最近接了一个项目其中有功能要实现一个清理内存，要求和微信的效果一样。于是想到用surfaceView而不是继承view。下面小编给大家解析下实现思路。
surfaceView是为了解决频繁绘制动画产生了闪烁，而采用了双缓冲机制，即A、B两个缓冲轮流显示在画布上，同时，使用不当，同样容易产生闪烁，这是由于A、B中有一个缓冲没有改变。
在我写这个view的时候就遇到了这个问题，研究了好久终于解决。
首先说一下思路：
微信清理缓存的动画是：
一个圆环不停的转动，同时中间有文字显示-->加载完成后，出现一个慢慢展开的图标，同时第一块区域要突出一点。
这就是微信的动画效果。但是具体实现是怎么样的呢？
下面说一下我实现的方法：
1、旋转圆环：
这个圆环由两部分组成，一个圆和一个深灰的弧线，而弧线一直在转动，产生了圆环在旋转的效果。
因此，这个就很好解决了。我们画两个图形，一个圆形，一个弧线，而弧线的角度不停的变化就产了旋转的效果。为了让它不断变化，就要用到一个动画类ValueAnimator,通过这个类不停的给出一个角度，然后我们不停的绘制，就可以完成这个效果。
2、文字：
文字是和圆环是一部分的，当然他们其实应该同时绘制。但是每次绘制，为了避免文字的重叠，我们需要将canvas清除。
我们通过计算出总的旋转动画时间和一个由绘制动画开始，到具体当前绘制时的时间差来模拟出百分比。
3、会展开的图表：
这个是这个效果的难点部分，这里遇到的问题也比较多。
这是一个慢慢展开的动画，看似是一个圆在慢慢显现，其实不是。只不过是一个扇形再不停的旋转，但是没有清除之前的画布，这样产生了平铺效果。而第一块区域的扇形较大只不过是半径大一点而已。因此这部分我们同样利用ValueAnimator，也可以画出。
通过对第一个旋转动画进行监听，当第一个效果结束的时候，第二个图表的动画开始进行。
4、具体的内存大小信息：
这个比较简单，只需要确定坐标即可，但是在写的时候也遇到了闪烁情况。
下面是具体实现
最初版本：
package xiaoqi.expandablechartview; import android.animation.Animator; import android.animation.PropertyValuesHolder; import android.animation.ValueAnimator; import android.content.Context; import android.graphics.Canvas; import android.graphics.Color; import android.graphics.Paint; import android.graphics.PixelFormat; import android.graphics.PorterDuff; import android.graphics.RectF; import android.util.AttributeSet; import android.view.SurfaceHolder; import android.view.SurfaceView; import android.view.animation.LinearInterpolator; public class ChartView extends SurfaceView implements SurfaceHolder.Callback { private Context context; private SurfaceHolder holder; private ValueAnimator chartAnimator; private ValueAnimator circleAnimator; //中间内存信息方块的坐标 private float centerDetailLeft; private float centerDetailTop; private float centerDetailRight; private float centerDetailBottom; //chart外接正方形坐标 private float chartLeft; private float chartTop; private float chartRight; private float chartBottom; //起始角度 private float startAngle = 270; //半径 private float radius; //各区域角度 private float area1Angle; private float area2Angle; //区域的量 private float total; private float area1; private float area2; private long time; private int repeatCount = 2; //是否为第一次显示，用于防止surface闪烁 private boolean area1IsFirstShow = true; private boolean area2IsFirstShow = true; //大扇形外接正方形 private RectF rectF; //小扇形外接正方形 private RectF rectF2; private Paint area1Paint; private Paint area2Paint; private Paint area3Paint; private Paint circlePaint; private Paint arcPaint; private Paint loadingPaint; private Paint textPaint; private static final int CIRCLE_DURATION = 1000; public ChartView(Context context) { super(context); this.context = context; init(); } public ChartView(Context context, AttributeSet attrs) { super(context, attrs); this.context = context; init(); } public ChartView(Context context, AttributeSet attrs, int defStyleAttr) { super(context, attrs, defStyleAttr); this.context = context; init(); } private void init() { radius = Utility.dip2px(context, 100); holder = getHolder(); holder.addCallback(this); setZOrderOnTop(true); holder.setFormat(PixelFormat.TRANSLUCENT); initPaint(); initAnimator(); } private void initAnimator() { PropertyValuesHolder angleValues = PropertyValuesHolder.ofFloat("angle", 0f, 360f); chartAnimator = ValueAnimator.ofPropertyValuesHolder(angleValues); chartAnimator.setDuration(2000); chartAnimator.setInterpolator(new LinearInterpolator()); chartAnimator.addUpdateListener(new ValueAnimator.AnimatorUpdateListener() { @Override public void onAnimationUpdate(ValueAnimator animation) { float angle = obj2Float(animation.getAnimatedValue("angle")); Canvas canvas = holder.lockCanvas(null); if(canvas != null){ // canvas.drawColor(Color.TRANSPARENT, PorterDuff.Mode.CLEAR); drawDetail(canvas); // canvas.setDrawFilter(new PaintFlagsDrawFilter(0, Paint.ANTI_ALIAS_FLAG | Paint.FILTER_BITMAP_FLAG)); // if (!area1IsFirstShow) { // canvas.drawArc(rectF, startAngle, area1Angle, true, area1Paint); // } // if (!area2IsFirstShow) { // canvas.drawArc(rectF2, area1Angle + startAngle, area2Angle, true, area2Paint); // } if (angle < area1Angle) { canvas.drawArc(rectF, startAngle, angle, true, area1Paint); } else if (angle <= area2Angle + area1Angle) { // if (area1IsFirstShow) { // area1IsFirstShow = false; // canvas.drawArc(rectF, startAngle, area1Angle, true, area1Paint); // } else { canvas.drawArc(rectF2, startAngle+area1Angle, angle - area1Angle, true, area2Paint); // } } else { // if (area2IsFirstShow) { // area2IsFirstShow = false; // canvas.drawArc(rectF2, area1Angle + startAngle, area2Angle, true, area2Paint); // } else { canvas.drawArc(rectF2, startAngle + area1Angle + area2Angle, angle - area2Angle - area1Angle, true, area3Paint); // } } holder.unlockCanvasAndPost(canvas); } } }); circleAnimator = ValueAnimator.ofPropertyValuesHolder(angleValues); circleAnimator.setInterpolator(new LinearInterpolator()); circleAnimator.setDuration(CIRCLE_DURATION); circleAnimator.addUpdateListener(new ValueAnimator.AnimatorUpdateListener() { @Override public void onAnimationUpdate(ValueAnimator animation) { float angle = obj2Float(animation.getAnimatedValue("angle")); Canvas canvas = holder.lockCanvas(null); if(canvas != null){ long nowTime = System.currentTimeMillis(); int rate = (int) (nowTime - time) / (CIRCLE_DURATION * (repeatCount + 1) / 100); if (rate <= 100) { canvas.drawColor(Color.TRANSPARENT, PorterDuff.Mode.CLEAR); canvas.drawText("正在加载" + rate + "%", getMeasuredWidth() / 2 - radius / 2, getMeasuredHeight() / 2, loadingPaint); } canvas.drawCircle(getMeasuredWidth() / 2, getMeasuredHeight() / 2 - Utility.dip2px(context, 10), radius, circlePaint); canvas.drawArc(rectF2, 180 + angle, 30, false, arcPaint); holder.unlockCanvasAndPost(canvas); } } }); circleAnimator.addListener(new Animator.AnimatorListener() { @Override public void onAnimationStart(Animator animation) { time = System.currentTimeMillis(); } @Override public void onAnimationEnd(Animator animation) { chartAnimator.start(); } @Override public void onAnimationCancel(Animator animation) { } @Override public void onAnimationRepeat(Animator animation) { } }); } private void initPaint() { area1Paint = new Paint(); area1Paint.setAntiAlias(true); area1Paint.setStyle(Paint.Style.FILL); area1Paint.setTextSize((Utility.dip2px(context, 15))); area1Paint.setColor(context.getResources().getColor(R.color.background_blue)); area2Paint = new Paint(); area2Paint.setAntiAlias(true); area2Paint.setStyle(Paint.Style.FILL); area2Paint.setTextSize((Utility.dip2px(context, 15))); area2Paint.setColor(context.getResources().getColor(R.color.chart_blue)); area3Paint = new Paint(); area3Paint.setAntiAlias(true); area3Paint.setStyle(Paint.Style.FILL); area3Paint.setTextSize((Utility.dip2px(context, 15))); area3Paint.setColor(context.getResources().getColor(R.color.light_gary)); circlePaint = new Paint(); circlePaint.setAntiAlias(true); circlePaint.setStrokeWidth(Utility.dip2px(context, 5)); circlePaint.setStyle(Paint.Style.STROKE); circlePaint.setColor(context.getResources().getColor(R.color.background_gray)); arcPaint = new Paint(); arcPaint.setAntiAlias(true); arcPaint.setStrokeWidth(Utility.dip2px(context, 5)); arcPaint.setStyle(Paint.Style.STROKE); arcPaint.setColor(context.getResources().getColor(R.color.textcolor_gray)); loadingPaint = new Paint(); loadingPaint.setTextSize((Utility.dip2px(context, 15))); loadingPaint.setColor(context.getResources().getColor(R.color.textcolor_gray)); textPaint = new Paint(); textPaint.setTextSize((Utility.dip2px(context, 15))); textPaint.setColor(context.getResources().getColor(R.color.black)); } private float obj2Float(Object o) { return ((Number) o).floatValue(); } @Override protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) { super.onMeasure(widthMeasureSpec, heightMeasureSpec); chartLeft = getMeasuredWidth() / 2 - radius; chartTop = getMeasuredHeight() / 2 - radius - Utility.dip2px(context, 10); chartRight = getMeasuredWidth() / 2 + radius; chartBottom = getMeasuredHeight() / 2 + radius - Utility.dip2px(context, 10); centerDetailLeft = getMeasuredWidth() / 2 - Utility.dip2px(context, 20); centerDetailTop = getMeasuredHeight() / 2 + radius + Utility.dip2px(context, 15); centerDetailRight = getMeasuredWidth() / 2; centerDetailBottom = getMeasuredHeight() / 2 + radius + Utility.dip2px(context, 35); } @Override protected void onDraw(Canvas canvas) { super.onDraw(canvas); } @Override public void surfaceCreated(SurfaceHolder holder) { rectF = new RectF(chartLeft - Utility.dip2px(context, 5), chartTop - Utility.dip2px(context, 5), chartRight + Utility.dip2px(context, 5), chartBottom + Utility.dip2px(context, 5)); rectF2 = new RectF(chartLeft, chartTop, chartRight, chartBottom); // valueAnimator.start(); } @Override public void surfaceChanged(SurfaceHolder holder, int format, int width, int height) { } @Override public void surfaceDestroyed(SurfaceHolder holder) { circleAnimator.cancel(); chartAnimator.cancel(); } private void drawDetail(Canvas canvas) { canvas.drawRect(centerDetailLeft - Utility.dip2px(context, 150), centerDetailTop, centerDetailRight - Utility.dip2px(context, 150), centerDetailBottom, area1Paint); canvas.drawRect(centerDetailLeft, centerDetailTop, centerDetailRight, centerDetailBottom, area2Paint); canvas.drawRect(centerDetailLeft + Utility.dip2px(context, 150), centerDetailTop, centerDetailRight + Utility.dip2px(context, 150), centerDetailBottom, area3Paint); drawText(canvas); } private void drawText(Canvas canvas) { canvas.drawText("本软件", centerDetailRight - Utility.dip2px(context, 150) + Utility.dip2px(context, 5), centerDetailTop + Utility.dip2px(context, 10), area1Paint); canvas.drawText("200MB", centerDetailRight - Utility.dip2px(context, 150) + Utility.dip2px(context, 5), centerDetailTop + Utility.dip2px(context, 25), textPaint); canvas.drawText("其他", centerDetailRight + Utility.dip2px(context, 5), centerDetailTop + Utility.dip2px(context, 10), area2Paint); canvas.drawText("24.1GB", centerDetailRight + Utility.dip2px(context, 5), centerDetailTop + Utility.dip2px(context, 25), textPaint); canvas.drawText("可用", centerDetailRight + Utility.dip2px(context, 150) + Utility.dip2px(context, 5), centerDetailTop + Utility.dip2px(context, 10), area3Paint); canvas.drawText("30GB", centerDetailRight + Utility.dip2px(context, 150) + Utility.dip2px(context, 5), centerDetailTop + Utility.dip2px(context, 25), textPaint); } public void show() { circleAnimator.setRepeatCount(repeatCount); circleAnimator.start(); } public void setArea1Color(int color) { area1Paint.setColor(color); } public void setArea2Color(int color) { area2Paint.setColor(color); } public void setArea3Color(int color) { area3Paint.setColor(color); } public void setRadius(float radius) { this.radius = radius; } public void setScale(float total, float area1, float area2){ area1Angle = area1/total * 360; area2Angle = area2/total * 360; } public void setRepeatCount(int repeatCount){ this.repeatCount = repeatCount; } }
效果：
模仿微信的效果基本显示出来了，但是当区域改变的时候，会不停闪烁，其实下面标注信息的小正方形也在闪烁，只不过我已经修改好了。
查了网上许多方法都没有给出一个很直接的答案，大部分都是说要对surfaceView前后缓存都进行绘制，这样就不产生闪烁问题。还有一种方法就是通过背景覆盖，让A缓冲在该区域的背景与B缓冲相同，这样自然而然切换的时候，就不会看到缓存交替而产生的闪烁问题了。
关于第一种，我并不是很理解，说是每次要改变前后两个缓冲，不能只变一个。。。。。。（网上都是这么说，但是我到底怎么改才算改！！？）
第二种方法，我经过了多次尝试实现了，通过切换画笔之后，每次画图都覆盖上一层，这样保持了之前闪烁部分的缓存一致。
该部分为找到的一些资料：
双缓存(Double-buffer)与黑屏闪烁
每个SurfaceView 对象有两个独立的graphic buffer，官方SDK将它们称作"front buffer"和"back buffer"。
常规的"double-buffer"会这么做：每一帧的数据都被绘制到back buffer，然后back buffer的内容被持续翻转(flip)到front buffer；屏幕一直显示front buffer。但Android SurfaceView的"double-buffer"却是这么做的：在buffer A里绘制内容，然后让屏幕显示buffer A; 下一个循环，在buffer B里绘制内容，然后让屏幕显示buffer B; 如此往复。于是，屏幕上显示的内容依次来自buffer A, B, A, B,....这样看来，两个buffer其实没有主从的分别，与其称之为"front buffer""back buffer"，毋宁称之为"buffer A""buffer B"。
Android中"double-buffer"的实现机制，可以很好地解释闪屏现象。在第一个"lockCanvas-drawCanvas-unlockCanvasAndPost"循环中，更新的是buffer A的内容；到下一个"lockCanvas-drawCanvas-unlockCanvasAndPost"循环中，更新的是buffer B的内容。如果buffer A与buffer B中某个buffer内容为空，当屏幕轮流显示它们时，就会出现画面黑屏闪烁现象。
解决方法
出现黑屏是因为buffer A与buffer B中一者内容为空，而且为空的一方还被post到了屏幕。于是有两种解决思路：
不让空buffer出现：每次向一个buffer写完内容并post之后，顺便用这个buffer的内容填充另一个buffer。这样能保证两个buffer的内容是同步的，缺点是做了无用功，耗费性能。
不post空buffer到屏幕：当准备更新内容时，先判断内容是否为空，只有非空时才启动"lockCanvas-drawCanvas-unlockCanvasAndPost"这个流程。
就好比，A缓存是白色，B缓冲是黑色（也就是前后surfaceView的缓存）。而黑色是surfaceView的默认色。比如下面的伪代码，通过线程不停的绘制：
canvas = holder.lockCanvas(); if(flag) { canvas.drawColor(Color.WHITE); } holder.unlockCanvasAndPost(canvas); flag = false;
看似没有什么问题，但是在实际过程却一直在黑白闪烁，这就是因为，虽然A我们每次都绘制了，但是B一直没变还是黑色。这时，我们通过覆盖，讲背景变为白色，就解决了这个问题，而我的解决方法也类似于这种。
下面贴出代码：
package xiaoqi.expandablechartview; import android.animation.Animator; import android.animation.PropertyValuesHolder; import android.animation.ValueAnimator; import android.content.Context; import android.graphics.Canvas; import android.graphics.Color; import android.graphics.Paint; import android.graphics.PixelFormat; import android.graphics.PorterDuff; import android.graphics.RectF; import android.util.AttributeSet; import android.view.SurfaceHolder; import android.view.SurfaceView; import android.view.animation.LinearInterpolator; public class ChartView extends SurfaceView implements SurfaceHolder.Callback { private Context context; private SurfaceHolder holder; private ValueAnimator chartAnimator; private ValueAnimator circleAnimator; //中间内存信息方块的坐标 private float centerDetailLeft; private float centerDetailTop; private float centerDetailRight; private float centerDetailBottom; //chart外接正方形坐标 private float chartLeft; private float chartTop; private float chartRight; private float chartBottom; //起始角度 private float startAngle = 270; //半径 private float radius; //各区域角度 private float area1Angle; private float area2Angle; //区域的量 private float total; private float area1; private float area2; private long time; private int repeatCount = 2; //是否为第一次显示，用于防止surface闪烁 private boolean area1IsFirstShow = true; private boolean area2IsFirstShow = true; //大扇形外接正方形 private RectF rectF; //小扇形外接正方形 private RectF rectF2; private Paint area1Paint; private Paint area2Paint; private Paint area3Paint; private Paint circlePaint; private Paint arcPaint; private Paint loadingPaint; private Paint textPaint; private static final int CIRCLE_DURATION = 1000; public ChartView(Context context) { super(context); this.context = context; init(); } public ChartView(Context context, AttributeSet attrs) { super(context, attrs); this.context = context; init(); } public ChartView(Context context, AttributeSet attrs, int defStyleAttr) { super(context, attrs, defStyleAttr); this.context = context; init(); } private void init() { radius = Utility.dip2px(context, 100); holder = getHolder(); holder.addCallback(this); setZOrderOnTop(true); holder.setFormat(PixelFormat.TRANSLUCENT); initPaint(); initAnimator(); } private void initAnimator() { PropertyValuesHolder angleValues = PropertyValuesHolder.ofFloat("angle", 0f, 360f); chartAnimator = ValueAnimator.ofPropertyValuesHolder(angleValues); chartAnimator.setDuration(2000); chartAnimator.setInterpolator(new LinearInterpolator()); chartAnimator.addUpdateListener(new ValueAnimator.AnimatorUpdateListener() { @Override public void onAnimationUpdate(ValueAnimator animation) { float angle = obj2Float(animation.getAnimatedValue("angle")); Canvas canvas = holder.lockCanvas(null); if(canvas != null){ canvas.drawColor(Color.TRANSPARENT, PorterDuff.Mode.CLEAR); drawDetail(canvas); // canvas.setDrawFilter(new PaintFlagsDrawFilter(0, Paint.ANTI_ALIAS_FLAG | Paint.FILTER_BITMAP_FLAG)); if (!area1IsFirstShow) { canvas.drawArc(rectF, startAngle, area1Angle, true, area1Paint); } if (!area2IsFirstShow) { canvas.drawArc(rectF2, area1Angle + startAngle, area2Angle, true, area2Paint); } if (angle < area1Angle) { canvas.drawArc(rectF, startAngle, angle, true, area1Paint); } else if (angle <= area2Angle + area1Angle) { if (area1IsFirstShow) { area1IsFirstShow = false; canvas.drawArc(rectF, startAngle, area1Angle, true, area1Paint); } else { canvas.drawArc(rectF2, startAngle+area1Angle, angle - area1Angle, true, area2Paint); } } else { if (area2IsFirstShow) { area2IsFirstShow = false; canvas.drawArc(rectF2, area1Angle + startAngle, area2Angle, true, area2Paint); } else { canvas.drawArc(rectF2, startAngle + area1Angle + area2Angle, angle - area2Angle - area1Angle, true, area3Paint); } } holder.unlockCanvasAndPost(canvas); } } }); circleAnimator = ValueAnimator.ofPropertyValuesHolder(angleValues); circleAnimator.setInterpolator(new LinearInterpolator()); circleAnimator.setDuration(CIRCLE_DURATION); circleAnimator.addUpdateListener(new ValueAnimator.AnimatorUpdateListener() { @Override public void onAnimationUpdate(ValueAnimator animation) { float angle = obj2Float(animation.getAnimatedValue("angle")); Canvas canvas = holder.lockCanvas(null); if(canvas != null){ long nowTime = System.currentTimeMillis(); int rate = (int) (nowTime - time) / (CIRCLE_DURATION * (repeatCount + 1) / 100); if (rate <= 100) { canvas.drawColor(Color.TRANSPARENT, PorterDuff.Mode.CLEAR); canvas.drawText("正在加载" + rate + "%", getMeasuredWidth() / 2 - radius / 2, getMeasuredHeight() / 2, loadingPaint); } canvas.drawCircle(getMeasuredWidth() / 2, getMeasuredHeight() / 2 - Utility.dip2px(context, 10), radius, circlePaint); canvas.drawArc(rectF2, 180 + angle, 30, false, arcPaint); holder.unlockCanvasAndPost(canvas); } } }); circleAnimator.addListener(new Animator.AnimatorListener() { @Override public void onAnimationStart(Animator animation) { time = System.currentTimeMillis(); } @Override public void onAnimationEnd(Animator animation) { chartAnimator.start(); } @Override public void onAnimationCancel(Animator animation) { } @Override public void onAnimationRepeat(Animator animation) { } }); } private void initPaint() { area1Paint = new Paint(); area1Paint.setAntiAlias(true); area1Paint.setStyle(Paint.Style.FILL); area1Paint.setTextSize((Utility.dip2px(context, 15))); area1Paint.setColor(context.getResources().getColor(R.color.background_blue)); area2Paint = new Paint(); area2Paint.setAntiAlias(true); area2Paint.setStyle(Paint.Style.FILL); area2Paint.setTextSize((Utility.dip2px(context, 15))); area2Paint.setColor(context.getResources().getColor(R.color.chart_blue)); area3Paint = new Paint(); area3Paint.setAntiAlias(true); area3Paint.setStyle(Paint.Style.FILL); area3Paint.setTextSize((Utility.dip2px(context, 15))); area3Paint.setColor(context.getResources().getColor(R.color.light_gary)); circlePaint = new Paint(); circlePaint.setAntiAlias(true); circlePaint.setStrokeWidth(Utility.dip2px(context, 5)); circlePaint.setStyle(Paint.Style.STROKE); circlePaint.setColor(context.getResources().getColor(R.color.background_gray)); arcPaint = new Paint(); arcPaint.setAntiAlias(true); arcPaint.setStrokeWidth(Utility.dip2px(context, 5)); arcPaint.setStyle(Paint.Style.STROKE); arcPaint.setColor(context.getResources().getColor(R.color.textcolor_gray)); loadingPaint = new Paint(); loadingPaint.setTextSize((Utility.dip2px(context, 15))); loadingPaint.setColor(context.getResources().getColor(R.color.textcolor_gray)); textPaint = new Paint(); textPaint.setTextSize((Utility.dip2px(context, 15))); textPaint.setColor(context.getResources().getColor(R.color.black)); } private float obj2Float(Object o) { return ((Number) o).floatValue(); } @Override protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) { super.onMeasure(widthMeasureSpec, heightMeasureSpec); chartLeft = getMeasuredWidth() / 2 - radius; chartTop = getMeasuredHeight() / 2 - radius - Utility.dip2px(context, 10); chartRight = getMeasuredWidth() / 2 + radius; chartBottom = getMeasuredHeight() / 2 + radius - Utility.dip2px(context, 10); centerDetailLeft = getMeasuredWidth() / 2 - Utility.dip2px(context, 20); centerDetailTop = getMeasuredHeight() / 2 + radius + Utility.dip2px(context, 15); centerDetailRight = getMeasuredWidth() / 2; centerDetailBottom = getMeasuredHeight() / 2 + radius + Utility.dip2px(context, 35); } @Override protected void onDraw(Canvas canvas) { super.onDraw(canvas); } @Override public void surfaceCreated(SurfaceHolder holder) { rectF = new RectF(chartLeft - Utility.dip2px(context, 5), chartTop - Utility.dip2px(context, 5), chartRight + Utility.dip2px(context, 5), chartBottom + Utility.dip2px(context, 5)); rectF2 = new RectF(chartLeft, chartTop, chartRight, chartBottom); // valueAnimator.start(); } @Override public void surfaceChanged(SurfaceHolder holder, int format, int width, int height) { } @Override public void surfaceDestroyed(SurfaceHolder holder) { circleAnimator.cancel(); chartAnimator.cancel(); } private void drawDetail(Canvas canvas) { canvas.drawRect(centerDetailLeft - Utility.dip2px(context, 150), centerDetailTop, centerDetailRight - Utility.dip2px(context, 150), centerDetailBottom, area1Paint); canvas.drawRect(centerDetailLeft, centerDetailTop, centerDetailRight, centerDetailBottom, area2Paint); canvas.drawRect(centerDetailLeft + Utility.dip2px(context, 150), centerDetailTop, centerDetailRight + Utility.dip2px(context, 150), centerDetailBottom, area3Paint); drawText(canvas); } private void drawText(Canvas canvas) { canvas.drawText("本软件", centerDetailRight - Utility.dip2px(context, 150) + Utility.dip2px(context, 5), centerDetailTop + Utility.dip2px(context, 10), area1Paint); canvas.drawText("200MB", centerDetailRight - Utility.dip2px(context, 150) + Utility.dip2px(context, 5), centerDetailTop + Utility.dip2px(context, 25), textPaint); canvas.drawText("其他", centerDetailRight + Utility.dip2px(context, 5), centerDetailTop + Utility.dip2px(context, 10), area2Paint); canvas.drawText("24.1GB", centerDetailRight + Utility.dip2px(context, 5), centerDetailTop + Utility.dip2px(context, 25), textPaint); canvas.drawText("可用", centerDetailRight + Utility.dip2px(context, 150) + Utility.dip2px(context, 5), centerDetailTop + Utility.dip2px(context, 10), area3Paint); canvas.drawText("30GB", centerDetailRight + Utility.dip2px(context, 150) + Utility.dip2px(context, 5), centerDetailTop + Utility.dip2px(context, 25), textPaint); } public void show() { circleAnimator.setRepeatCount(repeatCount); circleAnimator.start(); } public void setArea1Color(int color) { area1Paint.setColor(color); } public void setArea2Color(int color) { area2Paint.setColor(color); } public void setArea3Color(int color) { area3Paint.setColor(color); } public void setRadius(float radius) { this.radius = radius; } public void setScale(float total, float area1, float area2){ area1Angle = area1/total * 360; area2Angle = area2/total * 360; } public void setRepeatCount(int repeatCount){ this.repeatCount = repeatCount; } }
效果：
同时建议每个图形都用自己的paint，而不是通过重新set不同设置来调用paint，因为在使用时，我发现，因为很多地方用的是同一个paint也导致了闪烁，而为每个图形都创建了自己的paint之后就好了。
以上所述是小编给大家介绍的Android仿微信清理内存图表动画（解决surfaceView屏幕闪烁问题）demo实例详解，希望对大家有所帮助，如果大家有任何疑问请给我们留言，小编会及时回复大家的。在此也非常感谢大家对查字典教程网的支持！