【Android】【绘图】Canvas类，Paint类

canvas.save();
//保存画布状态

canvas.translate(10, 10);
//画布原点移到(10,10),默认为(0,0)

canvas.clipRect(0, 0, 100, 100); 
//设置绘图区域

Bitmap bitmap=BitmapFactory.decodeResource(getResources(), R.drawable.bitmap);
//从res获得bitmap

canvas.drawBitmap(bitmap, 0, 0, paint);
//绘制bitmap

canvas.restore();
//取出保存的画布状态

paint = new Paint();

paint.setColor(Color.WHITE);

paint.setStyle(Style.FILL);
//填充方式：实心

paint.setPathEffect(new CornerPathEffect(3));
//设置路径效果：圆角

Shader shader= new LinearGradient(0, 0, 100, 100,  new int[] { Color.RED, Color.GREEN, Color.BLUE, Color.YELLOW }, null, Shader.TileMode.REPEAT); 
 //定义阴影

paint.setShader(shader);
//设置阴影

paint.setAntiAlias(true);
//设置平滑边缘，这个操作会消耗资源