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scale(float sx,float sy)//对canvas执行缩放skew(float sx,float sy)//对canvas执行倾斜变换translate(float dx,float dy)//移动canvas，向右dx,向下dy//PathmoveTo(float x,float y)//Set the beginning of the next contour to the point (x,y). lineTo(float x,float y)//Add a line from the last point to the specified point (x,y). //canvasdrawTextOnPath(String text, Path path, float hOffset, float vOffset, Paint paint)//hOffset水平偏移 vOffset垂直偏移paint.setPathEffect(PathEffect effect); publicclassDrawView extends View{ // 定义记录前一个拖动事件发生点的坐标 float preX; float preY; privatePath path; publicPaint paint = null; // 定义一个内存中的图片，该图片将作为缓冲区 Bitmap cacheBitmap = null; // 定义cacheBitmap上的Canvas对象 Canvas cacheCanvas = null; publicDrawView(Context context,int width ,int height) { super(context); // 创建一个与该View相同大小的缓存区 cacheBitmap =Bitmap.createBitmap(width, height, Bitmap.Config.ARGB_8888); cacheCanvas =newCanvas(); path =newPath(); // 设置cacheCanvas将会绘制到内存中的cacheBitmap上 cacheCanvas.setBitmap(cacheBitmap); // 设置画笔的颜色 paint =newPaint(Paint.DITHER_FLAG); paint.setColor(Color.RED); // 设置画笔风格 paint.setStyle(Paint.Style.STROKE); paint.setStrokeWidth(1); // 反锯齿 paint.setAntiAlias(true); paint.setDither(true); } @Override public boolean onTouchEvent(MotionEvent event) { // 获取拖动事件的发生位置 float x = event.getX(); float y = event.getY(); switch(event.getAction()) { caseMotionEvent.ACTION_DOWN: // 从前一个点绘制到当前点之后，把当前点定义成下次绘制的前一个点 path.moveTo(x, y); preX = x; preY = y; break; caseMotionEvent.ACTION_MOVE: // 从前一个点绘制到当前点之后，把当前点定义成下次绘制的前一个点 path.quadTo(preX, preY, x, y); preX = x; preY = y; break; caseMotionEvent.ACTION_UP: cacheCanvas.drawPath(path, paint);// ① path.reset(); break; } invalidate(); // 返回true表明处理方法已经处理该事件 returntrue; } @Override publicvoid onDraw(Canvas canvas) { Paint bmpPaint =newPaint(); // 将cacheBitmap绘制到该View组件上 canvas.drawBitmap(cacheBitmap,0,0, bmpPaint);// ② // 沿着path绘制 canvas.drawPath(path, paint); }}标签：
原文地址：http://www.cnblogs.com/Doing-what-I-love/p/5533053.html
