Android如何播放GIF动画

Android支持GIF动画，但是如果利用ImageView标签直接写在布局文件中：

<ImageViewandroid:id="@+id/gifpicture"   
android:layout_width="fill_parent"   
android:layout_height="wrap_content"   
android:src="@drawable/animation"    />  

程序只能加载GIF动画的第一帧。效果如下：

如果想要正常播放GIF动画，需要借助Movie实现。写了一个简单示例，程序目录结构如下：


animation.gif是需要播放的GIF动画。
MainActivity实现了加载GIF动画的功能。

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publicclass MainActivity extends Activity {               private Movie mMovie;       privatelong mMovieStart;      /** Called when the activity is first created. */       @Override       publicvoid onCreate(Bundle savedInstanceState) {           super.onCreate(savedInstanceState);          setContentView(new CustomGifView(this));             }      class CustomGifView extends View {          public CustomGifView(Context context) {               super(context);               mMovie = Movie.decodeStream(getResources().openRawResource(                       R.drawable.animation));          }                       publicvoid onDraw(Canvas canvas) {              long now = android.os.SystemClock.uptimeMillis();                               if (mMovieStart == 0) { // first time                   mMovieStart = now;               }               if (mMovie != null) {                                       int dur = mMovie.duration();                   if (dur == 0) {                       dur = 1000;                   }                   int relTime = (int) ((now – mMovieStart) % dur);                                  mMovie.setTime(relTime);                   mMovie.draw(canvas, 0, 0);                   invalidate();               }           }      }  }

内部类CustomGifView 利用Movie播放GIF动画。解释一下：

mMovie = Movie.decodeStream(getResources().openRawResource(R.drawable.animation));  

将GIF动画以文件流的形式转换成Movie。

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publicvoid onDraw(Canvas canvas) {          long now = android.os.SystemClock.uptimeMillis();                       if (mMovieStart == 0) { // first time               mMovieStart = now;           }           if (mMovie != null) {                               int dur = mMovie.duration();               if (dur == 0) {                   dur = 1000;               }               int relTime = (int) ((now – mMovieStart) % dur);                              mMovie.setTime(relTime);               mMovie.draw(canvas, 0, 0);               invalidate();           }       }

invalidate();作用是刷新当前View，这样onDraw方法重复执行，Movie就能画出GIF动画的每一帧。到此，GIF动画就能正常播放了。

 

还有一种方法是根据配置文件，设置播放帧，显然是不推荐的。当然想了解，请看 http://developer.aiwgame.com/