Android仿微信清理內存圖表動畫（解決surfaceView屏幕閃爍問題）demo實例詳解

最近接了一個項目其中有功能要實現一個清理內存，要求和微信的效果一樣。於是想到用surfaceView而不是繼承view。下面小編給大家解析下實現思路。

surfaceView是為了解決頻繁繪制動畫產生了閃爍，而采用了雙緩沖機制，即A、B兩個緩沖輪流顯示在畫布上，同時，使用不當，同樣容易產生閃爍，這是由於A、B中有一個緩沖沒有改變。

在我寫這個view的時候就遇到了這個問題，研究了好久終於解決。

首先說一下思路：

微信清理緩存的動畫是：

一個圓環不停的轉動，同時中間有文字顯示-->加載完成後，出現一個慢慢展開的圖標，同時第一塊區域要突出一點。

這就是微信的動畫效果。但是具體實現是怎麼樣的呢？

下面說一下我實現的方法：

1、旋轉圓環：

這個圓環由兩部分組成，一個圓和一個深灰的弧線，而弧線一直在轉動，產生了圓環在旋轉的效果。

因此，這個就很好解決了。我們畫兩個圖形，一個圓形，一個弧線，而弧線的角度不停的變化就產了旋轉的效果。為了讓它不斷變化，就要用到一個動畫類ValueAnimator,通過這個類不停的給出一個角度，然後我們不停的繪制，就可以完成這個效果。

2、文字：

文字是和圓環是一部分的，當然他們其實應該同時繪制。但是每次繪制，為了避免文字的重疊，我們需要將canvas清除。

我們通過計算出總的旋轉動畫時間和一個由繪制動畫開始，到具體當前繪制時的時間差來模擬出百分比。

3、會展開的圖表：

這個是這個效果的難點部分，這裡遇到的問題也比較多。

這是一個慢慢展開的動畫，看似是一個圓在慢慢顯現，其實不是。只不過是一個扇形再不停的旋轉，但是沒有清除之前的畫布，這樣產生了平鋪效果。而第一塊區域的扇形較大只不過是半徑大一點而已。因此這部分我們同樣利用ValueAnimator，也可以畫出。

通過對第一個旋轉動畫進行監聽，當第一個效果結束的時候，第二個圖表的動畫開始進行。

4、具體的內存大小信息：

這個比較簡單，只需要確定坐標即可，但是在寫的時候也遇到了閃爍情況。

下面是具體實現

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; 
//中間內存信息方塊的坐標 
private float centerDetailLeft; 
private float centerDetailTop; 
private float centerDetailRight; 
private float centerDetailBottom; 
//chart外接正方形坐標 
private float chartLeft; 
private float chartTop; 
private float chartRight; 
private float chartBottom; 
//起始角度 
private float startAngle = 270; 
//半徑 
private float radius; 
//各區域角度 
private float area1Angle; 
private float area2Angle; 
//區域的量 
private float total; 
private float area1; 
private float area2; 
private long time; 
private int repeatCount = 2; 
//是否為第一次顯示，用於防止surface閃爍 
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("正在加載" + 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("本軟件", 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顯示出來了，但是當區域改變的時候，會不停閃爍，其實下面標注信息的小正方形也在閃爍，只不過我已經修改好了。

查了網上許多方法都沒有給出一個很直接的答案，大部分都是說要對surfaceView前後緩存都進行繪制，這樣就不產生閃爍問題。還有一種方法就是通過背景覆蓋，讓A緩沖在該區域的背景與B緩沖相同，這樣自然而然切換的時候，就不會看到緩存交替而產生的閃爍問題了。

關於第一種，我並不是很理解，說是每次要改變前後兩個緩沖，不能只變一個。。。。。。（網上都是這麼說，但是我到底怎麼改才算改！！？）

第二種方法，我經過了多次嘗試實現了，通過切換畫筆之後，每次畫圖都覆蓋上一層，這樣保持了之前閃爍部分的緩存一致。

該部分為找到的一些資料：

雙緩存(Double-buffer)與黑屏閃爍

每個SurfaceView 對象有兩個獨立的graphic buffer，官方SDK將它們稱作"front buffer"和"back buffer"。

常規的"double-buffer"會這麼做：每一幀的數據都被繪制到back buffer，然後back buffer的內容被持續翻轉(flip)到front buffer；屏幕一直顯示front buffer。但Android SurfaceView的"double-buffer"卻是這麼做的：在buffer A裡繪制內容，然後讓屏幕顯示buffer A; 下一個循環，在buffer B裡繪制內容，然後讓屏幕顯示buffer B; 如此往復。於是，屏幕上顯示的內容依次來自buffer A, B, A, B,....這樣看來，兩個buffer其實沒有主從的分別，與其稱之為"front buffer""back buffer"，毋寧稱之為"buffer A""buffer B"。

Android中"double-buffer"的實現機制，可以很好地解釋閃屏現象。在第一個"lockCanvas-drawCanvas-unlockCanvasAndPost"循環中，更新的是buffer A的內容；到下一個"lockCanvas-drawCanvas-unlockCanvasAndPost"循環中，更新的是buffer B的內容。如果buffer A與buffer B中某個buffer內容為空，當屏幕輪流顯示它們時，就會出現畫面黑屏閃爍現象。

解決方法

出現黑屏是因為buffer A與buffer B中一者內容為空，而且為空的一方還被post到了屏幕。於是有兩種解決思路：

不讓空buffer出現：每次向一個buffer寫完內容並post之後，順便用這個buffer的內容填充另一個buffer。這樣能保證兩個buffer的內容是同步的，缺點是做了無用功，耗費性能。

不post空buffer到屏幕：當准備更新內容時，先判斷內容是否為空，只有非空時才啟動"lockCanvas-drawCanvas-unlockCanvasAndPost"這個流程。

就好比，A緩存是白色，B緩沖是黑色（也就是前後surfaceView的緩存）。而黑色是surfaceView的默認色。比如下面的偽代碼，通過線程不停的繪制：

canvas = holder.lockCanvas(); 
if(flag) { 
canvas.drawColor(Color.WHITE); 
} 
holder.unlockCanvasAndPost(canvas); 
flag = false;

看似沒有什麼問題，但是在實際過程卻一直在黑白閃爍，這就是因為，雖然A我們每次都繪制了，但是B一直沒變還是黑色。這時，我們通過覆蓋，講背景變為白色，就解決了這個問題，而我的解決方法也類似於這種。

下面貼出代碼：

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; 
//中間內存信息方塊的坐標 
private float centerDetailLeft; 
private float centerDetailTop; 
private float centerDetailRight; 
private float centerDetailBottom; 
//chart外接正方形坐標 
private float chartLeft; 
private float chartTop; 
private float chartRight; 
private float chartBottom; 
//起始角度 
private float startAngle = 270; 
//半徑 
private float radius; 
//各區域角度 
private float area1Angle; 
private float area2Angle; 
//區域的量 
private float total; 
private float area1; 
private float area2; 
private long time; 
private int repeatCount = 2; 
//是否為第一次顯示，用於防止surface閃爍 
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("正在加載" + 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("本軟件", 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：

同時建議每個圖形都用自己的paint，而不是通過重新set不同設置來調用paint，因為在使用時，我發現，因為很多地方用的是同一個paint也導致了閃爍，而為每個圖形都創建了自己的paint之後就好了。

以上所述是小編給大家介紹的Android仿微信清理內存圖表動畫（解決surfaceView屏幕閃爍問題）demo實例詳解，希望對大家有所幫助，如果大家有任何疑問請給我留言，小編會及時回復大家的。在此也非常感謝大家對本站網站的支持！