前段时间做了个项目，有播放gif的需求，
而android展示gif的时候只是播放其第一帧.
主要原理呢，就是通过movie来播放gif的每一帧。
相关代码如下：
package com.em.widget;import java.io.InputStream;import android.annotation.SuppressLint;import android.content.Context;import android.content.res.TypedArray;import android.graphics.Canvas;import android.graphics.Movie;import android.os.Build;import android.util.AttributeSet;import android.view.View;import android.widget.ImageView;import com.em.R;public class Fsgifview extends ImageView { /** * 默认为1秒 */ private static final int DEFAULT_MOVIE_DURATION = 1000; private int mMovieResourceId; private Movie mMovie; private long mMovieStart; private int mCurrentAnimationTime = 0; private float mLeft; private float mTop; private float mScale; private int mMeasuredMovieWidth; private int mMeasuredMovieHeight; private boolean mVisible = true; // private volatile boolean mPaused = false; public Fsgifview(Context context) { this(context, null); } public Fsgifview(Context context, AttributeSet attrs) { this(context, attrs, R.styleable.FSGifViewStyle_drawablevalue); } public Fsgifview(Context context, AttributeSet attrs, int defStyle) { super(context, attrs, defStyle); setViewAttributes(context, attrs, defStyle); } @SuppressLint("NewApi") private void setViewAttributes(Context context, AttributeSet attrs, int defStyle) { if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.HONEYCOMB) { setLayerType(View.LAYER_TYPE_SOFTWARE, null); } // 从描述文件中读出gif的值，创建出Movie实例 final TypedArray array = context.obtainStyledAttributes(attrs, R.styleable.FSGifViewStyle, defStyle, 0); mMovieResourceId = array.getResourceId( R.styleable.FSGifViewStyle_drawablevalue, -1); array.recycle(); if (mMovieResourceId != -1) { //根据设置的gif资源文件获取到moive对象 mMovie = Movie.decodeStream(getResources().openRawResource( mMovieResourceId)); } } /** * 设置gif图资源 * * @param movieResId */ public void setMovieResource(int movieResId) { } @Override public void setImageResource(int resId) { this.mMovieResourceId = resId; InputStream is = getResources().openRawResource(mMovieResourceId); mMovie = Movie.decodeStream(is);//重写setimageResource方法，获取到赋值及时通知播放 requestLayout(); } public void setMovie(Movie movie) { this.mMovie = movie; requestLayout(); } public Movie getMovie() { return mMovie; } public void setMovieTime(int time) { mCurrentAnimationTime = time; invalidate(); } /** * 设置暂停 * * @param paused */ // public void setPaused(boolean paused) { // this.mPaused = paused; // if (!paused) { // mMovieStart = android.os.SystemClock.uptimeMillis() // - mCurrentAnimationTime; // } // invalidate(); // } /** * 判断gif图是否停止了 * * @return */ // public boolean isPaused() { // return this.mPaused; // } @Override protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) { if (mMovie != null) { int movieWidth = mMovie.width(); int movieHeight = mMovie.height(); int maximumWidth = MeasureSpec.getSize(widthMeasureSpec); float scaleW = (float) movieWidth / (float) maximumWidth; mScale = 1f / scaleW; mMeasuredMovieWidth = maximumWidth; mMeasuredMovieHeight = (int) (movieHeight * mScale); setMeasuredDimension(mMeasuredMovieWidth, mMeasuredMovieHeight); } else { setMeasuredDimension(getSuggestedMinimumWidth(), getSuggestedMinimumHeight()); } } @Override protected void onLayout(boolean changed, int l, int t, int r, int b) { super.onLayout(changed, l, t, r, b); mLeft = (getWidth() - mMeasuredMovieWidth) / 2f; mTop = (getHeight() - mMeasuredMovieHeight) / 2f; mVisible = getVisibility() == View.VISIBLE; } @Override protected void onDraw(Canvas canvas) { if (mMovie != null) { // if (!mPaused) { updateAnimationTime(); drawMovieFrame(canvas); invalidateView(); // } else { // drawMovieFrame(canvas); // } } } @SuppressLint("NewApi") private void invalidateView() { if (mVisible) { if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.JELLY_BEAN) { postInvalidateOnAnimation(); } else { invalidate(); } } } private void updateAnimationTime() { long now = android.os.SystemClock.uptimeMillis(); // 如果第一帧，记录起始时间 if (mMovieStart == 0) { mMovieStart = now; } // 取出动画的时长 int dur = mMovie.duration(); if (dur == 0) { dur = DEFAULT_MOVIE_DURATION; } // 算出需要显示第几帧 mCurrentAnimationTime = (int) ((now - mMovieStart) % dur); } private void drawMovieFrame(Canvas canvas) { // 设置要显示的帧，绘制即可 mMovie.setTime(mCurrentAnimationTime); canvas.save(Canvas.MATRIX_SAVE_FLAG); canvas.scale(mScale, mScale); mMovie.draw(canvas, mLeft / mScale, mTop / mScale); canvas.restore(); } @SuppressLint("NewApi") @Override public void onScreenStateChanged(int screenState) { super.onScreenStateChanged(screenState); mVisible = screenState == SCREEN_STATE_ON; invalidateView(); } @SuppressLint("NewApi") @Override protected void onVisibilityChanged(View changedView, int visibility) { super.onVisibilityChanged(changedView, visibility); mVisible = visibility == View.VISIBLE; invalidateView(); } @Override protected void onWindowVisibilityChanged(int visibility) { super.onWindowVisibilityChanged(visibility); mVisible = visibility == View.VISIBLE; invalidateView(); }}attr 属性文件中的配置，可以通过这个来获取到gif图像的值，用于decodestream播放gif
<declare-styleable name="FSGifViewStyle"> <attr name="drawablevalue" format="reference" /> </declare-styleable>