可以在Android中将动画gif文件设置为动态壁纸吗？

Question

我是Android平台的新手.我想开发一个动态壁纸应用程序.当我在搜索引擎中对此进行搜索时,他们中的许多人创建了一个动态壁纸作为他们的代码(使用SurfaceView和Canvas),我对此并不十分了解.我怀疑的是,任何可能将.gif图像设置为动态壁纸.

Answer 1

这是基本的壁纸服务(在动态壁纸教程中提供)被黑客攻击以显示动画gif.

首先 - 创建一个项目并将您的清单设置为动态壁纸.
然后 - 下载一个像这样的gif
   

将gif保存res/raw/nyan.gif在项目中.
创建一个动态壁纸服务,如本例所示.

public class NyanNyanService extends WallpaperService {
    static final String TAG = "NYAN";
    static final Handler mNyanHandler = new Handler();

    /**
     * @see android.service.wallpaper.WallpaperService#onCreate()
     */
    @Override
    public void onCreate() {
        super.onCreate();
    }

    /**
     * @see android.service.wallpaper.WallpaperService#onCreateEngine()
     */
    @Override
    public Engine onCreateEngine() {
        try {
            return new NyanEngine();
        } catch (IOException e) {
            Log.w(TAG, "Error creating NyanEngine", e);
            stopSelf();
            return null;
        }
    }

    class NyanEngine extends Engine {
        private final Movie mNyan;
        private final int mNyanDuration;
        private final Runnable mNyanNyan;
        float mScaleX;
        float mScaleY;
        int mWhen;
        long mStart;

        NyanEngine() throws IOException {
            InputStream is = getResources().openRawResource(R.raw.nyan);
            if (is != null) {
                try {
                    mNyan = Movie.decodeStream(is);
                    mNyanDuration = mNyan.duration();
                } finally {
                    is.close();
                }
            } else {
                throw new IOException("Unable to open R.raw.nyan");
            }

            mWhen = -1;
            mNyanNyan = new Runnable() {
                public void run() {
                    nyan();
                }
            };
        }

        @Override
        public void onDestroy() {
            super.onDestroy();
            mNyanHandler.removeCallbacks(mNyanNyan);
        }

        @Override
        public void onVisibilityChanged(boolean visible) {
            super.onVisibilityChanged(visible);
            if (visible) {
                nyan();
            } else {
                mNyanHandler.removeCallbacks(mNyanNyan);
            }
        }

        @Override
        public void onSurfaceChanged(SurfaceHolder holder, int format, int width, int height) {
            super.onSurfaceChanged(holder, format, width, height);
            mScaleX = width / (1f * mNyan.width());
            mScaleY = height / (1f * mNyan.height());
            nyan();
        }

        @Override
        public void onOffsetsChanged(float xOffset, float yOffset, float xOffsetStep,
                float yOffsetStep, int xPixelOffset, int yPixelOffset) {
            super.onOffsetsChanged(xOffset, yOffset, xOffsetStep, yOffsetStep, xPixelOffset, yPixelOffset);
            nyan();
        }

        void nyan() {
            tick();
            SurfaceHolder surfaceHolder = getSurfaceHolder();
            Canvas canvas = null;
            try {
                canvas = surfaceHolder.lockCanvas();
                if (canvas != null) {
                    nyanNyan(canvas);
                }
            } finally {
                if (canvas != null) {
                    surfaceHolder.unlockCanvasAndPost(canvas);
                }
            }
            mNyanHandler.removeCallbacks(mNyanNyan);
            if (isVisible()) {
                mNyanHandler.postDelayed(mNyanNyan, 1000L/25L);
            }
        }

        void tick() {
            if (mWhen == -1L) {
                mWhen = 0;
                mStart = SystemClock.uptimeMillis();
            } else {
                long mDiff = SystemClock.uptimeMillis() - mStart;
                mWhen = (int) (mDiff % mNyanDuration);
            }
        }

        void nyanNyan(Canvas canvas) {
            canvas.save();
            canvas.scale(mScaleX, mScaleY);
            mNyan.setTime(mWhen);
            mNyan.draw(canvas, 0, 0);
            canvas.restore();
        }
    }
}

这将基本上缩放nyan-nyan猫以适应屏幕并永久地制作它.

动态壁纸清单看起来像这样(此示例不包含配置活动):

<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
    package="your.nyan.nyan.package"
    android:versionCode="1"
    android:versionName="1.0" >
    <uses-sdk android:minSdkVersion="10" />
    <application
        android:icon="@drawable/ic_launcher"
        android:label="@string/application_nyan" > 
        <service 
            android:label="@string/wallpaper_nyan"
            android:name=".NyanNyanService"
            android:permission="android.permission.BIND_WALLPAPER">
            <intent-filter>
                <action android:name="android.service.wallpaper.WallpaperService" />
            </intent-filter>
            <meta-data android:name="android.service.wallpaper" android:resource="@xml/nyan" />
        </service>
    </application>
</manifest>

AndroidManifest.xml引用了一个文件res/xml,在本例中名为"nyan.xml":

<?xml version="1.0" encoding="utf-8"?>
<wallpaper xmlns:android="http://schemas.android.com/apk/res/android" />