Android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：

<ImageView android: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。

public class MainActivity extends Activity {         private Movie mMovie;     private long mMovieStart;    /** Called when the activity is first created. */     @Override     public void 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));        }                 public void 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。

public void 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。






源代码见：http://bigcateasymorse.googlecode.com/svn/trunk/android_gif_demo/