public static Bitmap toRoundImage(Bitmap bitmap) { float roundPx = 0; int rectStartX=0; int rectStartY=0; Bitmap output = Bitmap.createBitmap(bitmap.getWidth(), bitmap.getHeight(), Bitmap.Config.ARGB_8888); Rect rect=null;
/**
截取宽高较小的图片,就是截取正中间的正方形
*/ if (bitmap.getWidth()>bitmap.getHeight()){ roundPx=bitmap.getHeight()/2;//半径 rectStartX=(bitmap.getWidth()-bitmap.getHeight())/2; //矩形x开始位置 rect = new Rect(rectStartX, 0, bitmap.getWidth()-rectStartX, bitmap.getHeight());//取中间部分 }else{ roundPx=bitmap.getWidth()/2;//半径 rectStartY=(bitmap.getHeight()-bitmap.getWidth())/2; //矩形Y开始位置 rect = new Rect(0, rectStartY, bitmap.getWidth(), bitmap.getHeight()-rectStartY);//取中间部分 } Canvas canvas = new Canvas(output); int color = 0xff424242; Paint paint = new Paint(); RectF rectF = new RectF(rect); paint.setAntiAlias(true); canvas.drawARGB(0, 0, 0, 0); paint.setColor(color); canvas.drawRoundRect(rectF, roundPx, roundPx, paint); //画拐角,拐角的半径为正方形的边长一半 paint.setXfermode(new PorterDuffXfermode(PorterDuff.Mode.SRC_IN)); canvas.drawBitmap(bitmap, rect, rect, paint); return output; }
//下面上图来解释,就一目了然