圆角和圆形ImageView

※效果

※代码

/**
* 转换图片成圆形
*
* @param bitmap
*            传入Bitmap对象
* @return
*/
public Bitmap toRoundBitmap(Bitmap bitmap) {
int width = bitmap.getWidth();
int height = bitmap.getHeight();
float roundPx;
float left, top, right, bottom, dst_left, dst_top, dst_right, dst_bottom;
if (width <= height) {
roundPx = width / 2;

left = 0;
top = 0;
right = width;
bottom = width;

height = width;

dst_left = 0;
dst_top = 0;
dst_right = width;
dst_bottom = width;
} else {
roundPx = height / 2;

float clip = (width - height) / 2;

left = clip;
right = width - clip;
top = 0;
bottom = height;
width = height;

dst_left = 0;
dst_top = 0;
dst_right = height;
dst_bottom = height;
}

Bitmap output = Bitmap.createBitmap(width, height, Config.ARGB_8888);
Canvas canvas = new Canvas(output);

final Paint paint = new Paint();
final Rect src = new Rect((int) left, (int) top, (int) right, (int) bottom);
final Rect dst = new Rect((int) dst_left, (int) dst_top, (int) dst_right, (int) dst_bottom);
final RectF rectF = new RectF(dst);

paint.setAntiAlias(true);// 设置画笔无锯齿

canvas.drawARGB(0, 0, 0, 0); // 填充整个Canvas

// 以下有两种方法画圆,drawRounRect和drawCircle
canvas.drawRoundRect(rectF, roundPx, roundPx, paint);// 画圆角矩形，第一个参数为图形显示区域，第二个参数和第三个参数分别是水平圆角半径和垂直圆角半径。
// canvas.drawCircle(roundPx, roundPx, roundPx, paint);

paint.setXfermode(new PorterDuffXfermode(Mode.SRC_IN));// 设置两张图片相交时的模式,参考http://trylovecatch.iteye.com/blog/1189452
canvas.drawBitmap(bitmap, src, dst, paint); // 以Mode.SRC_IN模式合并bitmap和已经draw了的Circle

return output;
}

/**
* 圆角图片
* @param bitmap
* @return
*/
public static Bitmap getRoundedCornerBitmap(Bitmap bitmap) {
Bitmap output = Bitmap.createBitmap(bitmap.getWidth(),
bitmap.getHeight(), Config.ARGB_8888);
Canvas canvas = new Canvas(output);

final int color = 0xff424242;
final Paint paint = new Paint();
final Rect rect = new Rect(0, 0, bitmap.getWidth(), bitmap.getHeight());
final RectF rectF = new RectF(rect);
final float roundPx = 12;

paint.setAntiAlias(true);
canvas.drawARGB(0, 0, 0, 0);
paint.setColor(color);
canvas.drawRoundRect(rectF, roundPx, roundPx, paint);

paint.setXfermode(new PorterDuffXfermode(Mode.SRC_IN));
canvas.drawBitmap(bitmap, rect, rect, paint);

return output;

}

/***
* 设置图片倒影
* @param originalBitmap
* @return
*/
private Bitmap createReflectedImage(Bitmap originalBitmap) {
// 图片与倒影间隔距离
final int reflectionGap = 4;

// 图片的宽度
int width = originalBitmap.getWidth();
// 图片的高度
int height = originalBitmap.getHeight();

Matrix matrix = new Matrix();
// 图片缩放，x轴变为原来的1倍，y轴为-1倍,实现图片的反转
matrix.preScale(1, -1);
// 创建反转后的图片Bitmap对象，图片高是原图的一半。
Bitmap reflectionBitmap = Bitmap.createBitmap(originalBitmap, 0,
height / 2, width, height / 2, matrix, false);
// 创建标准的Bitmap对象，宽和原图一致，高是原图的1.5倍。
Bitmap withReflectionBitmap = Bitmap.createBitmap(width, (height
+ height / 2 + reflectionGap), Config.ARGB_8888);

// 构造函数传入Bitmap对象，为了在图片上画图
Canvas canvas = new Canvas(withReflectionBitmap);
// 画原始图片
canvas.drawBitmap(originalBitmap, 0, 0, null);

// 画间隔矩形
Paint defaultPaint = new Paint();
canvas.drawRect(0, height, width, height + reflectionGap, defaultPaint);

// 画倒影图片
canvas.drawBitmap(reflectionBitmap, 0, height + reflectionGap, null);

// 实现倒影效果
Paint paint = new Paint();
LinearGradient shader = new LinearGradient(0, originalBitmap.getHeight(),
0, withReflectionBitmap.getHeight(), 0x70ffffff, 0x00ffffff,
TileMode.MIRROR);
paint.setShader(shader);
paint.setXfermode(new PorterDuffXfermode(Mode.DST_IN));

// 覆盖效果
canvas.drawRect(0, height, width, withReflectionBitmap.getHeight(), paint);

return withReflectionBitmap;
}

※Demo下载