Android 逐帧动画OOM的解决方法

朱雀 2022-06-12 00:57 345阅读 0赞

项目中都会使用到动画，有时候会使用到逐帧动画，然后当帧数较多时，就会发生OOM的问题，网上有许多文字是提供一个工具类，解决这个方法。  
关于这个工具类的使用的原文地址：[http://blog.csdn.net/u014702999/article/details/50544455][http_blog.csdn.net_u014702999_article_details_50544455]

效果图（图片是gif需要等待一下才可以使用）：  
![SouthEast][]

这篇文章主要是换一种思路，如果我们只是需要动画每隔一段时间重复一次。那么我们仅使用gif图片进行展示就可以实现效果，下面提供一个我使用的GifView类，

**内存由原来的180M降到了14M**

package com.alpha.alphaapp.anim;
    
    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 com.alpha.alphaapp.R;
    
    public class GifView extends View { 
    
        /** * 默认为1秒 */
        private static final int DEFAULT_MOVIE_DURATION = 1000;
    
        private int mMovieResourceId;
    
        private Movie mMovie;
    
        private long mMovieStart;
        //当前动画
        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 GifView(Context context) {
            this(context, null);
        }
    
        public GifView(Context context, AttributeSet attrs) {
            this(context, attrs, R.styleable.CustomTheme_gifViewStyle);
        }
    
        public GifView(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.GifView, defStyle, R.style.Widget_GifView);
            mMovieResourceId = array.getResourceId(R.styleable.GifView_gif, -1);
            mPaused = array.getBoolean(R.styleable.GifView_paused, false);
            array.recycle();
            if (mMovieResourceId != -1) {
                mMovie = Movie.decodeStream(getResources().openRawResource(
                        mMovieResourceId));
            }
        }
    
        /** * 设置gif图资源 * * @param movieResId */
        public void setMovieResource(int movieResId) {
            this.mMovieResourceId = movieResId;
            mMovie = Movie.decodeStream(getResources().openRawResource(
                    mMovieResourceId));
            requestLayout();
        }
    
        public void setMovie(Movie movie) {
            this.mMovie = movie;
            requestLayout();
        }
    
        /** * 这里会停在最后一帧 */
        public void stop() {
            this.mPaused = true;
            //获取最后一帧,主要是为了让动画在设置暂停时停在最后一帧
            mCurrentAnimationTime = mMovie.duration();
            invalidate();
        }
    
        /** * 开始动画,重第一帧开始 */
        public void start() {
            this.mPaused = false;
            //获取最后一帧,主要是为了让动画在设置暂停时停在最后一帧
            mCurrentAnimationTime = 0;
            invalidate();
            //开始动画
    
        }
    
        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();
        }
    
    }

这个类是在别人的博客中找到的，自己又进行一些简单的修改，实现的效果与我用逐帧动画实现的效果一样，但**内存由原来的180M降到了14M,**简直瞬间感觉app都跑的快了，

在res/attrs中添加如下代码：

<declare-styleable name="GifView">
            <attr name="gif" format="reference" />
            <attr name="paused" format="boolean" />
        </declare-styleable>
        <declare-styleable name="CustomTheme">
            <attr name="gifViewStyle" format="reference" />
        </declare-styleable>

关于这类的使用如下，也是特别简单：  
layout.xml

<com.alpha.alphaapp.anim.GifView
       android:id="@+id/login_iv_sheep"
       android:layout_width="147.5dp"
       android:enabled="false"
       android:layout_height="match_parent"
    />

MainActvity中的使用

`R.raw.animation_sheep_normal`与`R.raw.animation_super_normal`就是放置到res/raw的gif图片资源

gif_sheep = (GifView) findViewById(R.id.login_iv_sheep);
       gif_super = (GifView) findViewById(R.id.login_iv_super);
         gif_sheep.setMovieResource(R.raw.animation_sheep_normal);
        gif_super.setMovieResource(R.raw.animation_super_normal);
            isStop = false;
            //每隔三秒开始播放动画
            runnable = new Runnable() {
                @Override
                public void run() {
                    //动画
                    gif_sheep.setPaused(isStop);
                    gif_super.setPaused(isStop);
                    isStop=!isStop;
                    handler.postDelayed(this, 3000);
                }
            };
            handler.postDelayed(runnable, 0);

Stop动画

public void stopNormalAnim() {
            gif_sheep.stop();
            gif_super.stop();
            handler.removeCallbacks(runnable);
        }

onDestroy  
最后在onDestroy中暂停动画

if（null!=gif_super）
      gif_super.setPaused(true);

这篇文章的题目有点与内容不符，但是我们在开发中，不就是实现了效果为主么，实现方式尽可能的简化。希望对大家有帮助。

[http_blog.csdn.net_u014702999_article_details_50544455]: http://blog.csdn.net/u014702999/article/details/50544455
[SouthEast]: /images/20220612/f91e682922174e1a9011e13091d45947.png