Android Image 圆角图片与圆形图片 ImageView

项目开发中遇到联系头像需要设置成圆角或者圆形图片

技术实现，自定义继承自ImageView 的子类，Override Ondraw

private Path clipPath =new Path();

// 圆角图

protected void onDraw(Canvas canvas) {

    clipPath.addRoundRect(new RectF(0, 0, getWidth(), getHeight()), 10.0f, 10.0f, Path.Direction.CW);

    canvas.clipPath(clipPath);
    super.onDraw(canvas);

}

其中10.0f 为圆角半径

如果是一张正方形的图片设置其值为getWidth()/2 实现效果是可以实现一个圆形图片效果的

// 圆形图

protected void onDraw(Canvas canvas) {

    clipPath.addCircle(getWidth()/2,getHeight()/2,getWidth()/2,Path.Direction.CCW);

    //clipPath.addRoundRect(new RectF(0, 0, getWidth(), getHeight()), 10.0f, 10.0f, Path.Direction.CW);

    canvas.clipPath(clipPath);
    super.onDraw(canvas);

}

也就是说在正方形图的基础上：

clipPath.addCircle(getWidth()/2,getHeight()/2,getWidth()/2,Path.Direction.CCW);

与

clipPath.addRoundRect(new RectF(0, 0, getWidth(), getHeight()), getWidth()/2, getHeitght()/2, Path.Direction.CW);

达到的效果一致，都可以实现一个圆图，

但是这样实现的圆图是有毛边的，

要继续优化界面，办法是有的：Canvas 在上面圆图的基础上再画一个圆边

//是Paint.Style.STROKE 不是FILL 不然就覆盖成一块饼了

private final Paint mButtonPaint = new Paint(Paint.ANTI_ALIAS_FLAG);

mButtonPaint.setStyle(Paint.Style.STROKE);
mButtonPaint.setColor(mColor);

// 圆形图

protected void onDraw(Canvas canvas) {

    clipPath.addCircle(getWidth()/2,getHeight()/2,getWidth()/2,Path.Direction.CCW);

    //clipPath.addRoundRect(new RectF(0, 0, getWidth(), getHeight()), 10.0f, 10.0f, Path.Direction.CW);

    canvas.clipPath(clipPath);
    super.onDraw(canvas);

    canvas.drawCircle(getWidth() / 2, getHeight() / 2, (float) (getWidth() / 2), mButtonPaint);

}

效果图：