MainActivity.java

public class MainActivity extends Activity {

@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.main);
}
}

AnimationView.java

import java.io.ByteArrayOutputStream;
import java.io.InputStream;

import android.content.Context;
import android.graphics.Canvas;
import android.graphics.Movie;
import android.util.AttributeSet;
import android.view.View;

public class AnimationView extends View {
private Movie mMovie;
private long mMovieStart;
private static final boolean DECODE_STREAM = true;

private int mDrawLeftPos;
private int mHeight,mWidth;

private static byte[] streamToBytes(InputStream is) {
    ByteArrayOutputStream os = new ByteArrayOutputStream(1024);
    byte[] buffer = new byte[1024];
    int len;
    try {
        while ((len = is.read(buffer)) >= 0) {
            os.write(buffer,len);
        }
    } catch (java.io.IOException e) {
    }
    return os.toByteArray();
}

public AnimationView(Context context,AttributeSet attrs) {
    super(context,attrs);
    setFocusable(true);
    java.io.InputStream is;
    is = context.getResources().openRawResource(R.drawable.scanning);
    if (DECODE_STREAM) {
        mMovie = Movie.decodeStream(is);
    } else {
        byte[] array = streamToBytes(is);
        mMovie = Movie.decodeByteArray(array,array.length);
    }
}

@Override
protected void onMeasure( int widthMeasureSpec,int heightMeasureSpec )
{   
    int p_top = this.getPaddingTop(),p_bottom = this.getPaddingBottom();

    mWidth = mMovie.width();
    mHeight = mMovie.height();
    // Calculate new desired height
    final int desiredHSpec = MeasureSpec.makeMeasureSpec( mHeight + p_top + p_bottom,MeasureSpec.EXACTLY );

    setMeasuredDimension( widthMeasureSpec,desiredHSpec );
    super.onMeasure( widthMeasureSpec,desiredHSpec );

    // Update the draw left position
    mDrawLeftPos = Math.max( ( this.getWidth() - mWidth ) / 2,0) ;
}

@Override
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 = 3000;
        }
        int relTime = (int) ((now - mMovieStart) % dur);
        // Log.d("","real time :: " +relTime);
        mMovie.setTime(relTime);
        mMovie.draw(canvas,mDrawLeftPos,this.getPaddingTop());
        invalidate();
    }
}
}

main.xml中

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:background="#FFFFFF"
android:orientation="vertical" >

<com.example.androidgifwork.AnimationView
                    android:layout_width="wrap_content"
                    android:layout_height="wrap_content"
                    android:layout_centerInParent="true" />
</LinearLayout>

的Manifest.xml

<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
package="com.example.androidgifwork"
android:versionCode="1"
android:versionName="1.0" >

<uses-sdk
    android:minSdkVersion="8"
    android:targetSdkVersion="19" />

<application
    android:icon="@drawable/ic_launcher"
    android:label="@string/app_name" >
    <activity
        android:name="com.example.androidgifwork.MainActivity"
        android:label="@string/app_name" >
        <intent-filter>
            <action android:name="android.intent.action.MAIN" />

            <category android:name="android.intent.category.LAUNCHER" />
        </intent-filter>
    </activity>
</application>

当我运行上面的代码片段GIF不是一直在运行,但是当我删除android：targetSdkVersion =“19”GIF运行,请帮我解决这个谜语.

谢谢