github项目之自定义图片形状（圆形和圆角矩形）

效果

关键代码分析

1.定义paint

paint = new Paint();
paint.setAntiAlias(true);

2.使用图片来渲染paint

BitmapShader shader = new BitmapShader(
    Bitmap.createScaledBitmap(image, canvasSize, canvasSize, false),
    Shader.TileMode.CLAMP,
    Shader.TileMode.CLAMP);
paint.setShader(shader);

3.利用RadialGradient的模糊效果和综合shader来渲染模糊的效果：

RadialGradient radialGradient = new RadialGradient(
                        circleCenter,
                        circleCenter,
                        circleCenter,
                        mColors,
                        mPositions,
                        Shader.TileMode.CLAMP);

ComposeShader composeShader = new ComposeShader(
                        shader,
                        radialGradient,
                        PorterDuff.Mode.SRC_OVER);

paint.setShader(composeShader);

4.使用paint来画形状
画圆角矩形：

canvas.drawRoundRect(
    new RectF(
        roundRectPadding,
        roundRectPadding,
        canvasSize-roundRectPadding,
        canvasSize-roundRectPadding),
    roundRectXRadius,
    roundRectYRadius,
    paint);

画圆：

canvas.drawCircle(
    circleCenter + borderWidth,
    circleCenter + borderWidth,
    ((canvasSize - (borderWidth * 2)) / 2) - 4.0f,
    paint);

参考资料

1.CircularImageView
https://github.com/lopspower/CircularImageView

2.circle and round rect image
https://github.com/hfreeman2008/AndroidDemo

3.Paint、Canvas、Matrix使用讲解(一、Paint)
http://blog.csdn.net/tianjian4592/article/details/44336949