[置顶] Android中使用Movie显示gif动态图

转载请注明：
http://blog.csdn.net/u012975705/article/details/48717391
在看这篇博文之前对attr自定义属性还是不是很熟的童鞋可以先看看：Android中attr详解（http://blog.csdn.net/u012975705/article/details/48716797）
源码下载：https://github.com/noyo/GifTest

效果图

显示的事两张动态gif图

实现代码

1、布局activity_main.xml

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android" android:layout_width="fill_parent" android:layout_height="fill_parent" xmlns:gif="http://schemas.android.com/apk/res-auto" android:gravity="center" android:orientation="vertical" >

    <com.practice.noyet.giftest.MyGiftView  android:id="@+id/gif1" gif:gif="@raw/gift1" android:layout_width="150dp" android:layout_height="150dp" android:layout_gravity="center_horizontal" android:enabled="false" />

    <com.practice.noyet.giftest.MyGiftView  android:layout_marginTop="10dp" gif:gif="@raw/gift2" android:id="@+id/gif2" android:layout_width="150dp" android:layout_height="150dp" android:layout_gravity="center_horizontal" android:enabled="false" />

</LinearLayout>

2、自定义的com.practice.noyet.giftest.MyGiftView.java代码（代码中都有注释，我就不废话了）：

package com.practice.noyet.giftest;

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

/** * Created by noyet on 2015/9/24. */
public class MyGiftView extends View {

    /** gift动态效果总时长，在未设置时长时默认为1秒 */
    private static final int DEFAULT_MOVIE_DURATION = 1000;
    /** gift图片资源ID */
    private int mGiftId;
    /** Movie实例，用来显示gift图片 */
    private Movie mMovie;
    /** 显示gift图片的动态效果的开始时间 */
    private long mMovieStart;
    /** 动态图当前显示第几帧 */
    private int mCurrentAnimationTime = 0;
    /** 图片离屏幕左边的距离 */
    private float mLeft;
    /** 图片离屏幕上边的距离 */
    private float mTop;
    /** 图片的缩放比例 */
    private float mScale;
    /** 图片在屏幕上显示的宽度 */
    private int mMeasuredMovieWidth;
    /** 图片在屏幕上显示的高度 */
    private int mMeasuredMovieHeight;
    /** 是否显示动画,为true表示显示，false表示不显示 */
    private boolean mVisible = true;
    /** 动画效果是否被暂停 */
    private volatile boolean mPaused = false;

    public MyGiftView(Context context) {
        this(context, null);
    }

    public MyGiftView(Context context, AttributeSet attrs) {
        this(context, attrs, R.styleable.CustomTheme_gifViewStyle);
    }

    public MyGiftView(Context context, AttributeSet attrs, int defStyleAttr) {
        super(context, attrs, defStyleAttr);
        setViewAttributes(context, attrs, defStyleAttr);
    }

    /** * * @param context 上下文 * @param attrs 自定义属性 * @param defStyle 默认风格 */
    @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);
        }

        final TypedArray array = context.obtainStyledAttributes(attrs,
                R.styleable.MyGiftView, defStyle, R.style.Widget_MyGiftView);
        mGiftId = array.getResourceId(R.styleable.MyGiftView_gif, -1);
        mPaused = array.getBoolean(R.styleable.MyGiftView_paused, false);
        array.recycle();
        if (mGiftId != -1) {
            byte[] bytes = getGiftBytes();
            mMovie = Movie.decodeByteArray(bytes, 0, bytes.length);
        }
    }

    /** * 设置gif图资源 * @param giftResId */
    public void setMovieResource(int giftResId) {
        this.mGiftId = giftResId;
        byte[] bytes = getGiftBytes();
        mMovie = Movie.decodeByteArray(bytes, 0, bytes.length);
        requestLayout();
    }

    /** * 手动设置 Movie对象 * @param movie Movie */
    public void setMovie(Movie movie) {
        this.mMovie = movie;
        requestLayout();
    }

    /** * 得到Movie对象 * @return Movie */
    public Movie getMovie() {
        return mMovie;
    }

    /** * 设置要显示第几帧动画 * @param time */
    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);
            }
        }
    }

    /** * 重绘 */
    @SuppressLint("NewApi")
    private void invalidateView() {
        if (mVisible) {
            if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.JELLY_BEAN) {
                postInvalidateOnAnimation();
            } else {
                invalidate();
            }
        }
    }

    /** * 更新当前显示进度 */
    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);
    }

    /** * 绘制图片 * @param canvas 画布 */
    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();
    }

    /** * 将gif图片转换成byte[] * @return byte[] */
    private byte[] getGiftBytes() {
        ByteArrayOutputStream baos = new ByteArrayOutputStream();
        InputStream is = getResources().openRawResource(mGiftId);
        byte[] b = new byte[1024];
        int len;
        try {
            while ((len = is.read(b, 0, 1024)) != -1) {
                baos.write(b, 0, len);
            }
            baos.flush();
        } catch (IOException e) {
            e.printStackTrace();
        } finally {
            if (is != null) {
                try {
                    is.close();
                } catch (IOException e) {
                    e.printStackTrace();
                }
            }
        }
        return baos.toByteArray();
    }
}

3、MainActivity.java：

package com.practice.noyet.giftest;

import android.app.Activity;
import android.os.Bundle;

public class MainActivity extends Activity {

    private MyGiftView gif1;
    private MyGiftView gif2;

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

        gif1 = (MyGiftView) findViewById(R.id.gif1);
        gif2 = (MyGiftView) findViewById(R.id.gif2);

        /** ........ */
    }

}