May 2014

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[Android ]Get Device Battery Information

<h1 class="headline" itemprop="name" style="color: #333333; font-family: Roboto, sans-serif; font-size: 40px; letter-spacing: -1px; line-height: 1.1em; margin: 10px 0px; padding-bottom: 5px; text-rendering: optimizelegibility; text-shadow: rgb(255, 255, 255) 0px 1px 0px;"></h1><div class="post_content" itemprop="articleBody"><div style="color: #333333; font-family: Roboto, sans-serif; font-size: 14px; line-height: 20px; margin-bottom: 10px;">The battery API is quite impressive, between other things not only can you get a battery’s voltage but you can also get the temperature, status and even an icon representing the current state of the battery.</div><div style="color: #333333; font-family: Roboto, sans-serif; font-size: 14px; line-height: 20px; margin-bottom: 10px;">In this post we’ll make an app that display’s all of the device’s battery information in a text view whenever there is a change of state in the battery.</div><h2 style="color: #333333; font-family: Roboto, sans-serif; font-size: 31.5px; line-height: 1.1em; margin: 10px 0px; padding-bottom: 5px; text-rendering: optimizelegibility; text-shadow: rgb(255, 255, 255) 0px 1px 0px;">The App’s Interface</h2><div style="color: #333333; font-family: Roboto, sans-serif; font-size: 14px; line-height: 20px; margin-bottom: 10px;">Our interface will consists of a simple text view where we will show the battery’s information and an image view where we will display the battery’s current state using the image provided by the API to do this.</div><div style="color: #333333; font-family: Roboto, sans-serif; font-size: 14px; line-height: 20px; margin-bottom: 10px;"> </div><div style="color: #333333; font-family: Roboto, sans-serif; font-size: 14px; line-height: 20px;"></div> <figure><figcaption style="color: #333333; font-family: Roboto, sans-serif; font-size: 14px; line-height: 20px;">File: layout/main.xml</figcaption><figcaption style="color: #333333; font-family: Roboto, sans-serif; font-size: 14px; line-height: 20px;"> </figcaption><figcaption><figcaption><?xml version="1.0" encoding="utf-8"?></figcaption><figcaption> </figcaption><figcaption><LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"</figcaption><figcaption> </figcaption><figcaption>    android:orientation="vertical"</figcaption><figcaption> </figcaption><figcaption>    android:layout_width="fill_parent"</figcaption><figcaption> </figcaption><figcaption>    android:layout_height="fill_parent"</figcaption><figcaption> </figcaption><figcaption>    ></figcaption><figcaption> </figcaption><figcaption> </figcaption><figcaption> </figcaption><figcaption>    <TextView</figcaption><figcaption> </figcaption><figcaption>        android:id="@+id/textViewBatteryInfo"</figcaption><figcaption> </figcaption><figcaption>        android:layout_width="wrap_content"</figcaption><figcaption> </figcaption><figcaption>        android:layout_height="wrap_content"</figcaption><figcaption> </figcaption><figcaption>        android:text="Battery Info: " /></figcaption><figcaption> </figcaption><figcaption> </figcaption><figcaption> </figcaption><figcaption>    <ImageView</figcaption><figcaption> </figcaption><figcaption>        android:id="@+id/imageViewBatteryState"</figcaption><figcaption> </figcaption><figcaption>        android:layout_width="wrap_content"</figcaption><figcaption> </figcaption><figcaption>        android:layout_height="wrap_content"</figcaption><figcaption> </figcaption><figcaption>        android:src="@drawable/icon" /></figcaption><figcaption> </figcaption><figcaption> </figcaption><figcaption> </figcaption><figcaption></LinearLayout></figcaption></figcaption></figure> <div style="color: #333333; font-family: Roboto, sans-serif; font-size: 14px; line-height: 20px; margin-bottom: 10px;"> </div><div style="color: #333333; font-family: Roboto, sans-serif; font-size: 14px; line-height: 20px; margin-bottom: 10px;">This is how the app will look.</div><div class="wp-caption aligncenter" style="background-color: #f4f4f4; border: 1px solid rgb(221, 221, 221); color: #333333; font-family: Roboto, sans-serif; font-size: 11px; font-style: italic; line-height: 20px; margin: 0px auto 1.571em; overflow: hidden; padding: 20px 20px 15px; text-align: center; width: 330px;"><img alt="Phone battery information" height="270" src="http://s3.amazonaws.com/MobileDevTuts/media/screenshots/posts/battery-information-android-app/phone-battery-info-connected-to-laptop.png" style="border: 0px; height: auto; max-width: 100%; vertical-align: middle;" title="phone battery information when connected to outlet" width="320" /> <div class="wp-caption-text" style="margin-bottom: 10px;">the result: an app showing the device's battery information</div></div><h2 style="color: #333333; font-family: Roboto, sans-serif; font-size: 31.5px; line-height: 1.1em; margin: 10px 0px; padding-bottom: 5px; text-rendering: optimizelegibility; text-shadow: rgb(255, 255, 255) 0px 1px 0px;">Receiving Battery Updates</h2><div style="color: #333333; font-family: Roboto, sans-serif; font-size: 14px; line-height: 20px; margin-bottom: 10px;">In order to receive the updated information from the battery we need to register a broadcast receiver and an intent filter. An intent filter tells the native battery app that our app is listening for its changes.</div><div style="color: #333333; float: left; font-family: Roboto, sans-serif; font-size: 14px; line-height: 20px; margin-bottom: 10px;"></div><div style="color: #333333; font-family: Roboto, sans-serif; font-size: 14px; height: 250px; line-height: 20px; text-align: center; width: 540px;"></div><div style="color: #333333; font-family: Roboto, sans-serif; font-size: 14px; line-height: 20px; margin-bottom: 10px;"></div><div style="color: #333333; font-family: Roboto, sans-serif; font-size: 14px; line-height: 20px; margin-bottom: 10px;"></div><div style="margin-bottom: 10px;"><div style="color: #333333; font-family: Roboto, sans-serif; font-size: 14px; line-height: 20px;">This is how we register a receiver with an intent filter:</div><div style="font-family: Roboto, sans-serif; font-size: 14px; line-height: 20px;"> </div>this.registerReceiver(this.batteryInfoReceiver, new IntentFilter(Intent.ACTION_BATTERY_CHANGED)); <div style="font-family: Roboto, sans-serif; font-size: 14px; line-height: 20px;"> </div><div style="color: #333333; font-family: Roboto, sans-serif; font-size: 14px; line-height: 20px;"> </div></div><div style="color: #333333; font-family: Roboto, sans-serif; font-size: 14px; line-height: 20px; margin-bottom: 10px;">In the code above the receiver is an object we are going to make called batteryInfoReceiver, the intent filter is listening for the action battery changed.</div><div style="margin-bottom: 10px;"><div style="font-family: Roboto, sans-serif; font-size: 14px; line-height: 20px;">Our receiver object is the following:</div>private BroadcastReceiver batteryInfoReceiver = new BroadcastReceiver() {   @Override   public void onReceive(Context context, Intent intent) {                   // this is where we deal with the data sent from the battery.   }  }; <div style="color: #333333; font-family: Roboto, sans-serif; font-size: 14px; line-height: 20px;"> </div><div style="color: #333333; font-family: Roboto, sans-serif; font-size: 14px; line-height: 20px;"> </div><div style="color: #333333; font-family: Roboto, sans-serif; font-size: 14px; line-height: 20px;">Battery Manager API</div></div><div style="color: #333333; font-family: Roboto, sans-serif; font-size: 14px; line-height: 20px; margin-bottom: 10px;">If you look at the <a href="http://developer.android.com/reference/android/os/BatteryManager.html#EXTRA_ICON_SMALL" style="color: #258aaf; text-decoration: none;" title="battery manager api">battery manager api</a> yo see that it has many constants that start with the word EXTRA_, these extras is the data we are able to get from the battery and also the type (int, String etc).</div><div style="color: #333333; font-family: Roboto, sans-serif; font-size: 14px; line-height: 20px;"></div> <figure><figcaption style="color: #333333; font-family: Roboto, sans-serif; font-size: 14px; line-height: 20px;">Storing the battery info in variables with matching types</figcaption><figcaption style="color: #333333; font-family: Roboto, sans-serif; font-size: 14px; line-height: 20px;"> </figcaption><figcaption><figcaption>int  health= intent.getIntExtra(BatteryManager.EXTRA_HEALTH,0);</figcaption><figcaption> </figcaption><figcaption>int  icon_small= intent.getIntExtra(BatteryManager.EXTRA_ICON_SMALL,0);</figcaption><figcaption> </figcaption><figcaption>int  level= intent.getIntExtra(BatteryManager.EXTRA_LEVEL,0);</figcaption><figcaption> </figcaption><figcaption>int  plugged= intent.getIntExtra(BatteryManager.EXTRA_PLUGGED,0);</figcaption><figcaption> </figcaption><figcaption>boolean  present= intent.getExtras().getBoolean(BatteryManager.EXTRA_PRESENT); </figcaption><figcaption> </figcaption><figcaption>int  scale= intent.getIntExtra(BatteryManager.EXTRA_SCALE,0);</figcaption><figcaption> </figcaption><figcaption>int  status= intent.getIntExtra(BatteryManager.EXTRA_STATUS,0);</figcaption><figcaption> </figcaption><figcaption>String  technology= intent.getExtras().getString(BatteryManager.EXTRA_TECHNOLOGY);</figcaption><figcaption> </figcaption><figcaption>int  temperature= intent.getIntExtra(BatteryManager.EXTRA_TEMPERATURE,0);</figcaption><figcaption> </figcaption><figcaption>int  voltage= intent.getIntExtra(BatteryManager.EXTRA_VOLTAGE,0);</figcaption><figcaption style="color: #333333; font-family: Roboto, sans-serif; font-size: 14px; line-height: 20px;"> </figcaption></figcaption></figure> <div style="color: #333333; font-family: Roboto, sans-serif; font-size: 14px; line-height: 20px;"></div><div style="color: #333333; font-family: Roboto, sans-serif; font-size: 14px; line-height: 20px; margin-bottom: 10px;">We can easily display the data in the views, the icon_small variable holds a resource id with the battery’s image:</div><div style="color: #333333; font-family: Roboto, sans-serif; font-size: 14px; line-height: 20px;"></div> <figure><figcaption style="color: #333333; font-family: Roboto, sans-serif; font-size: 14px; line-height: 20px;">Displaying data in text and image view</figcaption><figcaption style="color: #333333; font-family: Roboto, sans-serif; font-size: 14px; line-height: 20px;"> </figcaption><figcaption><figcaption>batteryInfo.setText(</figcaption><figcaption> </figcaption><figcaption> "Health: "+health+"\n"+</figcaption><figcaption> </figcaption><figcaption> "Icon Small:"+icon_small+"\n"+</figcaption><figcaption> </figcaption><figcaption> "Level: "+level+"\n"+</figcaption><figcaption> </figcaption><figcaption> "Plugged: "+plugged+"\n"+</figcaption><figcaption> </figcaption><figcaption> "Present: "+present+"\n"+</figcaption><figcaption> </figcaption><figcaption> "Scale: "+scale+"\n"+</figcaption><figcaption> </figcaption><figcaption> "Status: "+status+"\n"+</figcaption><figcaption> </figcaption><figcaption> "Technology: "+technology+"\n"+</figcaption><figcaption> </figcaption><figcaption> "Temperature: "+temperature+"\n"+</figcaption><figcaption> </figcaption><figcaption> "Voltage: "+voltage+"\n");</figcaption><figcaption> </figcaption><figcaption>imageBatteryState.setImageResource(icon_small);</figcaption></figcaption></figure> <div style="color: #333333; font-family: Roboto, sans-serif; font-size: 14px; line-height: 20px;"></div><div style="color: #333333; font-family: Roboto, sans-serif; font-size: 14px; line-height: 20px; margin-bottom: 10px;">This is the full Java code.</div><div style="color: #333333; font-family: Roboto, sans-serif; font-size: 14px; line-height: 20px;"></div> <figure><figcaption style="color: #333333; font-family: Roboto, sans-serif; font-size: 14px; line-height: 20px;">BatteryInformation.java</figcaption><figcaption style="color: #333333; font-family: Roboto, sans-serif; font-size: 14px; line-height: 20px;"> </figcaption><figcaption><figcaption> </figcaption><figcaption>package com.yoursite.batteryinformation;</figcaption><figcaption> </figcaption><figcaption> </figcaption><figcaption> </figcaption><figcaption>import android.app.Activity;</figcaption><figcaption> </figcaption><figcaption>import android.content.BroadcastReceiver;</figcaption><figcaption> </figcaption><figcaption>import android.content.Context;</figcaption><figcaption> </figcaption><figcaption>import android.content.Intent;</figcaption><figcaption> </figcaption><figcaption>import android.content.IntentFilter;</figcaption><figcaption> </figcaption><figcaption>import android.os.BatteryManager;</figcaption><figcaption> </figcaption><figcaption>import android.os.Bundle;</figcaption><figcaption> </figcaption><figcaption>import android.widget.ImageView;</figcaption><figcaption> </figcaption><figcaption>import android.widget.TextView;</figcaption><figcaption> </figcaption><figcaption> </figcaption><figcaption> </figcaption><figcaption> </figcaption><figcaption> </figcaption><figcaption>public class BatteryInformation extends Activity {</figcaption><figcaption> </figcaption><figcaption> private TextView batteryInfo;</figcaption><figcaption> </figcaption><figcaption> private ImageView imageBatteryState;</figcaption><figcaption> </figcaption><figcaption>    /** Called when the activity is first created. */</figcaption><figcaption> </figcaption><figcaption>    @Override</figcaption><figcaption> </figcaption><figcaption>    public void onCreate(Bundle savedInstanceState) {</figcaption><figcaption> </figcaption><figcaption>        super.onCreate(savedInstanceState);</figcaption><figcaption> </figcaption><figcaption>        setContentView(R.layout.main);</figcaption><figcaption> </figcaption><figcaption>        batteryInfo=(TextView)findViewById(R.id.textViewBatteryInfo);</figcaption><figcaption> </figcaption><figcaption>        imageBatteryState=(ImageView)findViewById(R.id.imageViewBatteryState);</figcaption><figcaption> </figcaption><figcaption>        </figcaption><figcaption> </figcaption><figcaption>        this.registerReceiver(this.batteryInfoReceiver, new IntentFilter(Intent.ACTION_BATTERY_CHANGED));</figcaption><figcaption> </figcaption><figcaption>    }</figcaption><figcaption> </figcaption><figcaption>    </figcaption><figcaption> </figcaption><figcaption>    private BroadcastReceiver batteryInfoReceiver = new BroadcastReceiver() {</figcaption><figcaption> </figcaption><figcaption>  @Override</figcaption><figcaption> </figcaption><figcaption>  public void onReceive(Context context, Intent intent) {</figcaption><figcaption> </figcaption><figcaption>   </figcaption><figcaption> </figcaption><figcaption>   int  health= intent.getIntExtra(BatteryManager.EXTRA_HEALTH,0);</figcaption><figcaption> </figcaption><figcaption>   int  icon_small= intent.getIntExtra(BatteryManager.EXTRA_ICON_SMALL,0);</figcaption><figcaption> </figcaption><figcaption>   int  level= intent.getIntExtra(BatteryManager.EXTRA_LEVEL,0);</figcaption><figcaption> </figcaption><figcaption>   int  plugged= intent.getIntExtra(BatteryManager.EXTRA_PLUGGED,0);</figcaption><figcaption> </figcaption><figcaption>   boolean  present= intent.getExtras().getBoolean(BatteryManager.EXTRA_PRESENT); </figcaption><figcaption> </figcaption><figcaption>   int  scale= intent.getIntExtra(BatteryManager.EXTRA_SCALE,0);</figcaption><figcaption> </figcaption><figcaption>   int  status= intent.getIntExtra(BatteryManager.EXTRA_STATUS,0);</figcaption><figcaption> </figcaption><figcaption>   String  technology= intent.getExtras().getString(BatteryManager.EXTRA_TECHNOLOGY);</figcaption><figcaption> </figcaption><figcaption>   int  temperature= intent.getIntExtra(BatteryManager.EXTRA_TEMPERATURE,0);</figcaption><figcaption> </figcaption><figcaption>   int  voltage= intent.getIntExtra(BatteryManager.EXTRA_VOLTAGE,0);</figcaption><figcaption> </figcaption><figcaption>   </figcaption><figcaption> </figcaption><figcaption> </figcaption><figcaption> </figcaption><figcaption>   batteryInfo.setText(</figcaption><figcaption> </figcaption><figcaption>     "Health: "+health+"\n"+</figcaption><figcaption> </figcaption><figcaption>     "Icon Small:"+icon_small+"\n"+</figcaption><figcaption> </figcaption><figcaption>     "Level: "+level+"\n"+</figcaption><figcaption> </figcaption><figcaption>     "Plugged: "+plugged+"\n"+</figcaption><figcaption> </figcaption><figcaption>     "Present: "+present+"\n"+</figcaption><figcaption> </figcaption><figcaption>     "Scale: "+scale+"\n"+</figcaption><figcaption> </figcaption><figcaption>     "Status: "+status+"\n"+</figcaption><figcaption> </figcaption><figcaption>     "Technology: "+technology+"\n"+</figcaption><figcaption> </figcaption><figcaption>     "Temperature: "+temperature+"\n"+</figcaption><figcaption> </figcaption><figcaption>     "Voltage: "+voltage+"\n");</figcaption><figcaption> </figcaption><figcaption>   imageBatteryState.setImageResource(icon_small);</figcaption><figcaption> </figcaption><figcaption>  }</figcaption><figcaption> </figcaption><figcaption> };</figcaption><figcaption> </figcaption><figcaption>    </figcaption><figcaption> </figcaption><figcaption> </figcaption><figcaption> </figcaption><figcaption>}</figcaption><figcaption style="color: #333333; font-family: Roboto, sans-serif; font-size: 14px; line-height: 20px;"> </figcaption></figcaption></figure> <div style="color: #333333; font-family: Roboto, sans-serif; font-size: 14px; line-height: 20px;"></div><h2 style="color: #333333; font-family: Roboto, sans-serif; font-size: 31.5px; line-height: 1.1em; margin: 10px 0px; padding-bottom: 5px; text-rendering: optimizelegibility; text-shadow: rgb(255, 255, 255) 0px 1px 0px;">Battery Permissions</h2><div style="color: #333333; font-family: Roboto, sans-serif; font-size: 14px; line-height: 20px; margin-bottom: 10px;">No special permissions are needed in the manifest file.</div><div style="margin-bottom: 10px;"><div style="color: #333333; font-family: Roboto, sans-serif; font-size: 14px; line-height: 20px;">No related posts.</div><div style="color: #333333; font-family: Roboto, sans-serif; font-size: 14px; line-height: 20px;"> </div><div style="color: #333333; font-family: Roboto, sans-serif; font-size: 14px; line-height: 20px;">Nguon: suu tam</div>http://android.programmerguru.com/android-broadcast-receiver-example/ broadcast receiver battery low</div></div>

The battery API is quite impressive, between other things not only can you get a battery’s voltage but you can also get the temperature, sta...

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[Android] Set Text Color for TextView Android

<div style="background-color: white; border: 0px; clear: both; font-family: Arial, 'Liberation Sans', 'DejaVu Sans', sans-serif; font-size: 13.63636302947998px; line-height: 17.804800033569336px; margin-bottom: 1em; padding: 0px; vertical-align: baseline;">In the string.xml file use the following tag</div><pre class="default prettyprint prettyprinted" style="background-color: #eeeeee; border: 0px; font-family: Consolas, Menlo, Monaco, 'Lucida Console', 'Liberation Mono', 'DejaVu Sans Mono', 'Bitstream Vera Sans Mono', 'Courier New', monospace, serif; font-size: 13.63636302947998px; line-height: 17.804800033569336px; margin-bottom: 10px; max-height: 600px; overflow: auto; padding: 5px; vertical-align: baseline; width: auto; word-wrap: normal;"><code style="border: 0px; font-family: Consolas, Menlo, Monaco, 'Lucida Console', 'Liberation Mono', 'DejaVu Sans Mono', 'Bitstream Vera Sans Mono', 'Courier New', monospace, serif; font-size: 13.63636302947998px; margin: 0px; padding: 0px; vertical-align: baseline; white-space: inherit;"> <string name="CodeColor" >"#0000ff"</string></code></pre><div style="background-color: white; border: 0px; clear: both; font-family: Arial, 'Liberation Sans', 'DejaVu Sans', sans-serif; font-size: 13.63636302947998px; line-height: 17.804800033569336px; margin-bottom: 1em; padding: 0px; vertical-align: baseline;">In the layout files you can call to the colors or styles:</div><pre class="default prettyprint prettyprinted" style="background-color: #eeeeee; border: 0px; font-family: Consolas, Menlo, Monaco, 'Lucida Console', 'Liberation Mono', 'DejaVu Sans Mono', 'Bitstream Vera Sans Mono', 'Courier New', monospace, serif; font-size: 13.63636302947998px; line-height: 17.804800033569336px; margin-bottom: 10px; max-height: 600px; overflow: auto; padding: 5px; vertical-align: baseline; width: auto; word-wrap: normal;"><code style="border: 0px; font-family: Consolas, Menlo, Monaco, 'Lucida Console', 'Liberation Mono', 'DejaVu Sans Mono', 'Bitstream Vera Sans Mono', 'Courier New', monospace, serif; font-size: 13.63636302947998px; margin: 0px; padding: 0px; vertical-align: baseline; white-space: inherit;">android:textColor="@color/titlecolor"</code></pre><div style="background-color: white; border: 0px; clear: both; font-family: Arial, 'Liberation Sans', 'DejaVu Sans', sans-serif; font-size: 13.63636302947998px; line-height: 17.804800033569336px; margin-bottom: 1em; padding: 0px; vertical-align: baseline;">Or you can use:</div><a name='more'></a> <div style="background-color: white; border: 0px; clear: both; font-family: Arial, 'Liberation Sans', 'DejaVu Sans', sans-serif; font-size: 13.63636302947998px; line-height: 17.804800033569336px; margin-bottom: 1em; padding: 0px; vertical-align: baseline;">You can use</div><pre class="default prettyprint prettyprinted" style="background-color: #eeeeee; border: 0px; font-family: Consolas, Menlo, Monaco, 'Lucida Console', 'Liberation Mono', 'DejaVu Sans Mono', 'Bitstream Vera Sans Mono', 'Courier New', monospace, serif; font-size: 13.63636302947998px; line-height: 17.804800033569336px; margin-bottom: 10px; max-height: 600px; overflow: auto; padding: 5px; vertical-align: baseline; width: auto; word-wrap: normal;"><code style="border: 0px; font-family: Consolas, Menlo, Monaco, 'Lucida Console', 'Liberation Mono', 'DejaVu Sans Mono', 'Bitstream Vera Sans Mono', 'Courier New', monospace, serif; font-size: 13.63636302947998px; margin: 0px; padding: 0px; vertical-align: baseline; white-space: inherit;"> textView1.setTextColor(getResources().getColor(R.color.mycolor))</code></pre><div style="background-color: white; border: 0px; clear: both; font-family: Arial, 'Liberation Sans', 'DejaVu Sans', sans-serif; font-size: 13.63636302947998px; line-height: 17.804800033569336px; margin-bottom: 1em; padding: 0px; vertical-align: baseline;">or</div><pre class="default prettyprint prettyprinted" style="background-color: #eeeeee; border: 0px; font-family: Consolas, Menlo, Monaco, 'Lucida Console', 'Liberation Mono', 'DejaVu Sans Mono', 'Bitstream Vera Sans Mono', 'Courier New', monospace, serif; font-size: 13.63636302947998px; line-height: 17.804800033569336px; margin-bottom: 10px; max-height: 600px; overflow: auto; padding: 5px; vertical-align: baseline; width: auto; word-wrap: normal;"><code style="border: 0px; font-family: Consolas, Menlo, Monaco, 'Lucida Console', 'Liberation Mono', 'DejaVu Sans Mono', 'Bitstream Vera Sans Mono', 'Courier New', monospace, serif; font-size: 13.63636302947998px; margin: 0px; padding: 0px; vertical-align: baseline; white-space: inherit;"> textview1.setBackgroundColor(<span class="typ" style="background-color: transparent; background-position: initial initial; background-repeat: initial initial; border: 0px; color: #2b91af; font-size: 13.63636302947998px; margin: 0px; padding: 0px; vertical-align: baseline;">Color.parseColor(<span class="str" style="background-color: transparent; background-position: initial initial; background-repeat: initial initial; border: 0px; color: maroon; font-size: 13.63636302947998px; margin: 0px; padding: 0px; vertical-align: baseline;">"#ffffff"));</code></pre><div style="background-color: white; border: 0px; clear: both; font-family: Arial, 'Liberation Sans', 'DejaVu Sans', sans-serif; font-size: 13.63636302947998px; line-height: 17.804800033569336px; margin-bottom: 1em; padding: 0px; vertical-align: baseline;">or</div><pre class="default prettyprint prettyprinted" style="background-color: #eeeeee; border: 0px; font-family: Consolas, Menlo, Monaco, 'Lucida Console', 'Liberation Mono', 'DejaVu Sans Mono', 'Bitstream Vera Sans Mono', 'Courier New', monospace, serif; font-size: 13.63636302947998px; line-height: 17.804800033569336px; margin-bottom: 10px; max-height: 600px; overflow: auto; padding: 5px; vertical-align: baseline; width: auto; word-wrap: normal;"><code style="border: 0px; font-family: Consolas, Menlo, Monaco, 'Lucida Console', 'Liberation Mono', 'DejaVu Sans Mono', 'Bitstream Vera Sans Mono', 'Courier New', monospace, serif; font-size: 13.63636302947998px; margin: 0px; padding: 0px; vertical-align: baseline; white-space: inherit;"> textview1.setBackgroundColor(<span class="typ" style="background-color: transparent; background-position: initial initial; background-repeat: initial initial; border: 0px; color: #2b91af; font-size: 13.63636302947998px; margin: 0px; padding: 0px; vertical-align: baseline;">Color.RED);</code></pre><div style="background-color: white; border: 0px; clear: both; font-family: Arial, 'Liberation Sans', 'DejaVu Sans', sans-serif; font-size: 13.63636302947998px; line-height: 17.804800033569336px; margin-bottom: 1em; padding: 0px; vertical-align: baseline;">or</div><pre class="default prettyprint prettyprinted" style="background-color: #eeeeee; border: 0px; font-family: Consolas, Menlo, Monaco, 'Lucida Console', 'Liberation Mono', 'DejaVu Sans Mono', 'Bitstream Vera Sans Mono', 'Courier New', monospace, serif; font-size: 13.63636302947998px; line-height: 17.804800033569336px; margin-bottom: 10px; max-height: 600px; overflow: auto; padding: 5px; vertical-align: baseline; width: auto; word-wrap: normal;"><code style="border: 0px; font-family: Consolas, Menlo, Monaco, 'Lucida Console', 'Liberation Mono', 'DejaVu Sans Mono', 'Bitstream Vera Sans Mono', 'Courier New', monospace, serif; font-size: 13.63636302947998px; margin: 0px; padding: 0px; vertical-align: baseline; white-space: inherit;"> textView1.setBackgroundColor(R.color.black);</code></pre>

In the string.xml file use the following tag <string name = "CodeColor" > "#0000ff" </string> In the layo...

[Android Game] Bài 6: Xét va chạm

<div style="border-bottom: solid #4F81BD 1.0pt; border: none; mso-element: para-border-div; padding: 0in 0in 4.0pt 0in;"><div class="MsoTitle"> </div></div><div class="MsoNormal">Phát triển tiếp từ bài 5: <a href="http://thanhcs.blogspot.com/2014/05/android-game-bai-5-tao-ke-thu.html" target="_blank">http://thanhcs.blogspot.com/2014/05/android-game-bai-5-tao-ke-thu.html</a><o:p></o:p></div><div class="MsoNormal">Phần này ta sẽ xét va chạm giữa các đối tượng.</div><div class="separator" style="clear: both; text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEj2g_57Nc6nwC6MYiczs1eZW_6pcePvf67CihzijEtzO8oYzgA6wYniajuw-yrl1-Cc55V4oVtjoJdHYbJnR5Vr_H2UDV8IKl6xv1IUG_mTn_TJiDnlbCE-Z4-D4zkBZJwV0tJBkE3AYhM/s1600/image002.gif" imageanchor="1" style="clear: left; float: left; margin-bottom: 1em; margin-right: 1em;">      <img border="0" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEj2g_57Nc6nwC6MYiczs1eZW_6pcePvf67CihzijEtzO8oYzgA6wYniajuw-yrl1-Cc55V4oVtjoJdHYbJnR5Vr_H2UDV8IKl6xv1IUG_mTn_TJiDnlbCE-Z4-D4zkBZJwV0tJBkE3AYhM/s1600/image002.gif" /></a><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEhdapTKxNb-OnqGBKSi_ggE4g-iGYJjpwA8eH_ldR3MdQNIWDMa4yseJ6ItH12yF27umBLTGP5i1Yj32qvv6qS1l-hVWWFaQS4Bkif1jVBvrzgAwswrPeU-ncgllLCahnMWfTdn7LWWXko/s1600/image004.gif" imageanchor="1" style="margin-left: 1em; margin-right: 1em;"><img border="0" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEhdapTKxNb-OnqGBKSi_ggE4g-iGYJjpwA8eH_ldR3MdQNIWDMa4yseJ6ItH12yF27umBLTGP5i1Yj32qvv6qS1l-hVWWFaQS4Bkif1jVBvrzgAwswrPeU-ncgllLCahnMWfTdn7LWWXko/s1600/image004.gif" /></a></div><o:p></o:p> <div align="center" class="MsoNormal" style="text-align: center;"><o:p></o:p></div><div class="MsoNormal">Theo thuật toán ta thấy rằng 2 hình chữ nhật chạm nhau khi thỏa 2 điều kiện (cho 2 trục x,y là).<o:p></o:p></div><div class="MsoListParagraphCxSpFirst" style="mso-list: l2 level1 lfo1; text-indent: -.25in;">·        Kích thước từ tâm của HCN_A đến tâm của HCN_B  theo trục  x <= nửa rộng HCN_A + nửa rộng HCN_B<o:p></o:p></div><div class="MsoListParagraphCxSpLast" style="mso-list: l2 level1 lfo1; text-indent: -.25in;">·        Kích thước từ tâm của HCN_A đến tâm của HCN_B theo trục y <= nửa cao HCN_A + nửa cao HCN_B<o:p></o:p></div><div class="MsoNormal">Các đại lượng này ta đều có thể tính được vì ta có tọa độ x,y của từng HCN và có kích thước của từng HCN.</div><a name='more'></a><o:p></o:p> <h2>Phần 1: Sửa class Enemies và Bullet</h2><div class="MsoNormal">Giờ ta phải bổ sung cho 2 class là Bullet và Enemies các hàm để lấy được chiều rộng và chiều cao của đối tượng, và thêm hàm để lấy tâm theo trục X, tâm theo trục Y. <o:p></o:p></div><div class="MsoListParagraph" style="mso-list: l1 level1 lfo2; text-indent: -.25in;">1.      Mở file Bullet và thêm 4 hàm như sau:<o:p></o:p></div><div style="border: solid windowtext 1.0pt; mso-border-alt: solid windowtext .5pt; mso-element: para-border-div; padding: 1.0pt 4.0pt 1.0pt 4.0pt;"><div class="MsoNormal" style="border: none; margin-bottom: 0.0001pt; padding: 0in;">publicint getWidth()<o:p></o:p></div><div class="MsoNormal" style="border: none; margin-bottom: 0.0001pt; padding: 0in;">{<o:p></o:p></div><div class="MsoNormal" style="border: none; margin-bottom: 0.0001pt; padding: 0in;">     returnbitmap.getWidth();<o:p></o:p></div><div class="MsoNormal" style="border: none; margin-bottom: 0.0001pt; padding: 0in;">}<o:p></o:p></div><div class="MsoNormal" style="border: none; margin-bottom: 0.0001pt; padding: 0in;">publicint getHeight()<o:p></o:p></div><div class="MsoNormal" style="border: none; margin-bottom: 0.0001pt; padding: 0in;">{<o:p></o:p></div><div class="MsoNormal" style="border: none; margin-bottom: 0.0001pt; padding: 0in;">     returnbitmap.getHeight();<o:p></o:p></div><div class="MsoNormal" style="border: none; margin-bottom: 0.0001pt; padding: 0in;">}<o:p></o:p></div><div class="MsoNormal" style="border: none; margin-bottom: 0.0001pt; padding: 0in;">publicint gettamX()<o:p></o:p></div><div class="MsoNormal" style="border: none; margin-bottom: 0.0001pt; padding: 0in;">{<o:p></o:p></div><div class="MsoNormal" style="border: none; margin-bottom: 0.0001pt; padding: 0in;">     //tam x=toa do x congvoinuarong<o:p></o:p></div><div class="MsoNormal" style="border: none; margin-bottom: 0.0001pt; padding: 0in;">     returnx+(bitmap.getWidth()/2);<o:p></o:p></div><div class="MsoNormal" style="border: none; margin-bottom: 0.0001pt; padding: 0in;">}<o:p></o:p></div><div class="MsoNormal" style="border: none; margin-bottom: 0.0001pt; padding: 0in;">publicint gettamY()<o:p></o:p></div><div class="MsoNormal" style="border: none; margin-bottom: 0.0001pt; padding: 0in;">{<o:p></o:p></div><div class="MsoNormal" style="border: none; margin-bottom: 0.0001pt; padding: 0in;">     //tam y=toa do y congnuacao<o:p></o:p></div><div class="MsoNormal" style="border: none; margin-bottom: 0.0001pt; padding: 0in;">     returny+(bitmap.getHeight()/2);<o:p></o:p></div><div class="MsoNormal" style="border: none; mso-border-alt: solid windowtext .5pt; mso-padding-alt: 1.0pt 4.0pt 1.0pt 4.0pt; padding: 0in;">}<o:p></o:p></div></div><div class="MsoListParagraph" style="mso-list: l1 level1 lfo2; text-indent: -.25in;">2.      Copy đoạn 4 hàm vừa tạo trong Bullet, mở class Enemies và paste 4 hàm này vào.<o:p></o:p></div><h2>Phần 2: Xây dựng hàm va chạm trong GamePanel</h2><div class="MsoListParagraph" style="mso-list: l0 level1 lfo3; text-indent: -.25in;">1.      Mở file GamePanel.java ta tạo ra một hàm mới vc_b_e, hàm này dùng để xét va chạm giữa bullet và enemies. Nó nhận vào 1 bullet và một enemies sau đó tính ra các thông tin cần thiết rồi xét điều kiện, nếu thỏa điều kiện tức là có va chạm nó trả về true, ngược lại không có va chạm thì trả về false, (có thể viết ngắn hơn nhưng chẻ ra cho nó dễ hiểu ;-)  )<o:p></o:p></div><div style="border: solid windowtext 1.0pt; mso-border-alt: solid windowtext .5pt; mso-element: para-border-div; padding: 1.0pt 4.0pt 1.0pt 4.0pt;"><div class="MsoNormal" style="border: none; margin-bottom: 0.0001pt; padding: 0in;">publicboolean vc_b_e(Bullet bullet,Enemies enemies)<o:p></o:p></div><div class="MsoNormal" style="border: none; margin-bottom: 0.0001pt; padding: 0in;">{<o:p></o:p></div><div class="MsoNormal" style="border: none; margin-bottom: 0.0001pt; padding: 0in;">     <o:p></o:p></div><div class="MsoNormal" style="border: none; margin-bottom: 0.0001pt; padding: 0in;">     float nuarong_b=(float)bullet.getWidth()/2;<o:p></o:p></div><div class="MsoNormal" style="border: none; margin-bottom: 0.0001pt; padding: 0in;">     int nuacao_b=bullet.getHeight()/2;<o:p></o:p></div><div class="MsoNormal" style="border: none; margin-bottom: 0.0001pt; padding: 0in;">     float nuarong_e=(float)enemies.getWidth()/2;<o:p></o:p></div><div class="MsoNormal" style="border: none; margin-bottom: 0.0001pt; padding: 0in;">     int nuacao_e=enemies.getHeight()/2;<o:p></o:p></div><div class="MsoNormal" style="border: none; margin-bottom: 0.0001pt; padding: 0in;">     //khoangcach 2 tamtheo x<o:p></o:p></div><div class="MsoNormal" style="border: none; margin-bottom: 0.0001pt; padding: 0in;">     int kc_ht_x=Math.abs(bullet.gettamX()-enemies.gettamX());<o:p></o:p></div><div class="MsoNormal" style="border: none; margin-bottom: 0.0001pt; padding: 0in;">     //khoangcach 2 tamtheo y<o:p></o:p></div><div class="MsoNormal" style="border: none; margin-bottom: 0.0001pt; padding: 0in;">     int kc_ht_y=Math.abs(bullet.gettamY()-enemies.gettamY());<o:p></o:p></div><div class="MsoNormal" style="border: none; margin-bottom: 0.0001pt; padding: 0in;">     if(kc_ht_x<=nuarong_b+nuarong_e && kc_ht_y<=nuacao_b+nuacao_e)<o:p></o:p></div><div class="MsoNormal" style="border: none; margin-bottom: 0.0001pt; padding: 0in;">          returntrue;<o:p></o:p></div><div class="MsoNormal" style="border: none; margin-bottom: 0.0001pt; padding: 0in;">     else<o:p></o:p></div><div class="MsoNormal" style="border: none; margin-bottom: 0.0001pt; padding: 0in;">          returnfalse;<o:p></o:p></div><div class="MsoNormal" style="border: none; mso-border-alt: solid windowtext .5pt; mso-padding-alt: 1.0pt 4.0pt 1.0pt 4.0pt; padding: 0in;">}<o:p></o:p></div></div><div class="MsoListParagraph" style="mso-list: l0 level1 lfo3; text-indent: -.25in;">2.      Tiếp theo ta xây một hàm mới tên “xetvacham” hàm này sẽ duyệt tất cả bullets và tương ứng với mỗi bullets sẽ duyệt tất cả enemies để xét xem nó có va chạm không, nếu có va chạm giữa một bullets và một enemies nào đó sẽ xóa 2 thằng đó ra khỏi ArrayList. Chỗ này nên để trong try catch.<o:p></o:p></div><div style="border: solid windowtext 1.0pt; mso-border-alt: solid windowtext .5pt; mso-element: para-border-div; padding: 1.0pt 4.0pt 1.0pt 4.0pt;"><div class="MsoNormal" style="border: none; margin-bottom: 0.0001pt; padding: 0in;">publicvoidxetvacham(Canvas canvas)<o:p></o:p></div><div class="MsoNormal" style="border: none; margin-bottom: 0.0001pt; padding: 0in;">{<o:p></o:p></div><div class="MsoNormal" style="border: none; margin-bottom: 0.0001pt; padding: 0in;">     try{<o:p></o:p></div><div class="MsoNormal" style="border: none; margin-bottom: 0.0001pt; padding: 0in;">          for(int i=0;i<bullets.size();i++)<o:p></o:p></div><div class="MsoNormal" style="border: none; margin-bottom: 0.0001pt; padding: 0in;">              for(int j=0;j<enemies.size();j++)<o:p></o:p></div><div class="MsoNormal" style="border: none; margin-bottom: 0.0001pt; padding: 0in;">              {<o:p></o:p></div><div class="MsoNormal" style="border: none; margin-bottom: 0.0001pt; padding: 0in;">                   if(vc_b_e(bullets.get(i), enemies.get(j))==true)<o:p></o:p></div><div class="MsoNormal" style="border: none; margin-bottom: 0.0001pt; padding: 0in;">                   {<o:p></o:p></div><div class="MsoNormal" style="border: none; margin-bottom: 0.0001pt; padding: 0in;">                        bullets.remove(i);<o:p></o:p></div><div class="MsoNormal" style="border: none; margin-bottom: 0.0001pt; padding: 0in;">                        enemies.remove(j);<o:p></o:p></div><div class="MsoNormal" style="border: none; margin-bottom: 0.0001pt; padding: 0in;">                   }<o:p></o:p></div><div class="MsoNormal" style="border: none; margin-bottom: 0.0001pt; padding: 0in;">              }<o:p></o:p></div><div class="MsoNormal" style="border: none; margin-bottom: 0.0001pt; padding: 0in;">     }catch(Exception e)<o:p></o:p></div><div class="MsoNormal" style="border: none; margin-bottom: 0.0001pt; padding: 0in;">     {<o:p></o:p></div><div class="MsoNormal" style="border: none; margin-bottom: 0.0001pt; padding: 0in;">          Log.d("loi",e.toString());<o:p></o:p></div><div class="MsoNormal" style="border: none; margin-bottom: 0.0001pt; padding: 0in;">     }<o:p></o:p></div><div class="MsoNormal" style="border: none; margin-bottom: 0.0001pt; padding: 0in;">     <o:p></o:p></div><div class="MsoNormal" style="border: none; mso-border-alt: solid windowtext .5pt; mso-padding-alt: 1.0pt 4.0pt 1.0pt 4.0pt; padding: 0in;">}<o:p></o:p></div></div><div class="MsoListParagraph" style="mso-list: l0 level1 lfo3; text-indent: -.25in;">3.      Cuối cùng trong hàm onDraw, sau khi vẽ bullet và enemies xong ta gọi hàm xetvacham để bỏ các đối tượng đã va chạm với nhau.<o:p></o:p></div><div style="border: solid windowtext 1.0pt; mso-border-alt: solid windowtext .5pt; mso-element: para-border-div; padding: 1.0pt 4.0pt 1.0pt 4.0pt;"><div class="MsoNormal" style="border: none; margin-bottom: 0.0001pt; padding: 0in;">          <a href="https://www.blogger.com/null" name="_GoBack"></a>if(myelement!=null)<o:p></o:p></div><div class="MsoNormal" style="border: none; margin-bottom: 0.0001pt; padding: 0in;">          {<o:p></o:p></div><div class="MsoNormal" style="border: none; margin-bottom: 0.0001pt; padding: 0in;">              myelement.doDraw(canvas);//vemay bay<o:p></o:p></div><div class="MsoNormal" style="border: none; margin-bottom: 0.0001pt; padding: 0in;">              this.doDrawBullet(canvas); //vetap hop viendan<o:p></o:p></div><div class="MsoNormal" style="border: none; margin-bottom: 0.0001pt; padding: 0in;">              this.doDrawEnemies(canvas);//vetap hop Enemies<o:p></o:p></div><div class="MsoNormal" style="border: none; margin-bottom: 0.0001pt; padding: 0in;">              xetvacham(canvas);//xetvacham<o:p></o:p></div><div class="MsoNormal" style="border: none; mso-border-alt: solid windowtext .5pt; mso-padding-alt: 1.0pt 4.0pt 1.0pt 4.0pt; padding: 0in;">          }<o:p></o:p></div></div> <div class="MsoNormal"> </div>

Phát triển tiếp từ bài 5: http://thanhcs.blogspot.com/2014/05/android-game-bai-5-tao-ke-thu.html Phần này ta sẽ xét va chạm giữa các đối tư...

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