}

RubblerShow类：

public class RubblerShow extends TextView {

private float TOUCH_TOLERANCE; // 填充距离，使线条更自然，柔和,值越小，越柔和。

// private final int bgColor;

private Bitmap mBitmap;
private Canvas mCanvas;
private Paint mPaint;
private Path mPath;
private float mX, mY;

private boolean isDraw = false;

Handler handler;
int time=0;

public RubblerShow(Context context, Handler handler) {
super(context);
this.handler=handler;
// bgColor =
// attrs.getAttributeIntValue("http://schemas.android.com/apk/res/android",
// "textColor", 0xFFFFFF);
// System.out.println(bgColor);
// System.out.println(attrs.getAttributeva lue("http://schemas.android.com/apk/res/android",
// "layout_width"));
}

@Override
protected void onDraw(Canvas canvas) {
super.onDraw(canvas);
if (isDraw) {
mCanvas.drawPath(mPath, mPaint);
// mCanvas.drawPoint(mX, mY, mPaint);
canvas.drawBitmap(mBitmap, 0, 0, null);
}
}

/**
* 开启檫除功能
*
* @param bgColor
* 覆盖的背景颜色
* @param paintStrokeWidth
* 触点（橡皮）宽度
* @param touchTolerance
* 填充距离,值越小，越柔和。
*/
public void beginRubbler(final int bgColor, final int paintStrokeWidth,
float touchTolerance) {
TOUCH_TOLERANCE = touchTolerance;
// 设置画笔
mPaint = new Paint();
// mPaint.setAlpha(0);
// 画笔划过的痕迹就变成透明色了
mPaint.setColor(Color.BLACK); // 此处不能为透明色
mPaint.setXfermode(new PorterDuffXfermode(PorterDuff.Mode.DST_OUT));
// 或者
// mPaint.setAlpha(0);
// mPaint.setXfermode(new PorterDuffXfermode(PorterDuff.Mode.DST_IN));

mPaint.setAntiAlias(true);
mPaint.setDither(true);
mPaint.setStyle(Paint.Style.STROKE);
mPaint.setStrokeJoin(Paint.Join.ROUND); // 前圆角
mPaint.setStrokeCap(Paint.Cap.ROUND); // 后圆角
mPaint.setStrokeWidth(paintStrokeWidth); // 笔宽

// 痕迹
mPath = new Path();
// 覆盖
LayoutParams layoutParams = getLayoutParams();
int height = layoutParams.height;
int width;
if (getLayoutParams().width == LayoutParams.MATCH_PARENT) {
width = 700;
} else {
width = layoutParams.width;
}

mBitmap = Bitmap.createBitmap(width, height, Config.ARGB_8888);
mCanvas = new Canvas(mBitmap);

mCanvas.drawColor(bgColor);
isDraw = true;
}

@Override
public boolean onTouchEvent(MotionEvent event) {
if (!isDraw) {
return true;
}
switch (event.getAction()) {
case MotionEvent.ACTION_DOWN: // 触点按下
// touchDown(event.getRawX(),event.getRawY());
touchDown(event.getX(), event.getY());
invalidate();
break;
case MotionEvent.ACTION_MOVE: // 触点移动
touchMove(event.getX(), event.getY());
invalidate();
if(time++>3&&handler!=null){
handler.sendEmptyMessage(200);
}
break;
case MotionEvent.ACTION_UP: // 触点弹起
touchUp(event.getX(), event.getY());
invalidate();
break;
default:
break;
}
return true;
}

private void touchDown(float x, float y) {
mPath.reset();
mPath.moveTo(x, y);
mX = x;
mY = y;
}

private void touchMove(float x, float y) {
float dx = Math.abs(x - mX);
float dy = Math.abs(y - mY);
if (dx >= TOUCH_TOLERANCE || dy >= TOUCH_TOLERANCE) {
mPath.quadTo(mX, mY, (x + mX) / 2, (y + mY) / 2);
mX = x;
mY = y;
}

}

private void touchUp(float x, float y) {
mPath.lineTo(x, y);
mCanvas.drawPath(mPath, mPaint);
mPath.reset();
}

}