方法1: 使用RoundedBitmapDrawable

public static RoundedBitmapDrawable bitmapToRoundedDrawable(@NonNull Resources res, @NonNull Bitmap bitmap,boolean circular, float cornerRadius) {RoundedBitmapDrawable drawable = RoundedBitmapDrawableFactory.create(res, bitmap);drawable.setAlpha(255);//设置透明度drawable.setAntiAlias(true);//设置抗锯齿drawable.setDither(true);//设置防抖动drawable.setGravity(Gravity.CENTER);if (circular) {drawable.setCircular(true);//设置正圆形} else {drawable.setCornerRadius(cornerRadius);//设置圆角半径}return drawable;}final Bitmap bitmap = BitmapFactory.decodeResource(getResources(), R.drawable.test);
//圆形照片
final Drawable circleDrawable = Util.bitmapToRoundedDrawable(getResources(), bitmap, true, 0);
mImageView1.setImageDrawable(circleDrawable);
//圆角照片
final Drawable roundedDrawable = Util.bitmapToRoundedDrawable(getResources(), bitmap, false, 100);
mImageView2.setImageDrawable(roundedDrawable);

使用RoundedBitmapDrawable生成带边框的圆形照片：

public static Drawable bitmapToRoundedDrawableWithBorder(Resources res, Bitmap bitmap) {//原图宽度int bitmapWidth = bitmap.getWidth();//原图高度int bitmapHeight = bitmap.getHeight();//边框宽度 pixelint borderWidthHalf = 20;//转换为正方形后的宽高int bitmapSquareWidth = Math.min(bitmapWidth, bitmapHeight);//最终图像的宽高int newBitmapSquareWidth = bitmapSquareWidth + borderWidthHalf;Bitmap roundedBitmap = Bitmap.createBitmap(newBitmapSquareWidth, newBitmapSquareWidth, Bitmap.Config.ARGB_8888);Canvas canvas = new Canvas(roundedBitmap);int x = borderWidthHalf + bitmapSquareWidth - bitmapWidth;int y = borderWidthHalf + bitmapSquareWidth - bitmapHeight;//裁剪后图像,注意X,Y要除以2 来进行一个中心裁剪canvas.drawBitmap(bitmap, x / 2, y / 2, null);Paint borderPaint = new Paint();borderPaint.setAntiAlias(true);borderPaint.setStyle(Paint.Style.STROKE);borderPaint.setStrokeWidth(borderWidthHalf);borderPaint.setColor(Color.GRAY);//添加边框canvas.drawCircle(canvas.getWidth() / 2, canvas.getWidth() / 2, newBitmapSquareWidth / 2, borderPaint);return bitmapToRoundedDrawable(res, roundedBitmap, true, 0);}
final Drawable roundedDrawableWithBorder = Util.bitmapToRoundedDrawableWithBorder(getResources(), bitmap);
mImageView3.setImageDrawable(roundedDrawableWithBorder);

方法2: 使用PorterDuffXfermode(PorterDuff.Mode.SRC_IN)实现圆角照片

public static Bitmap getRoundedCornerBitmap(Bitmap bitmap) {try {int width = bitmap.getWidth();int height = bitmap.getHeight();Bitmap output = Bitmap.createBitmap(width, height, Bitmap.Config.ARGB_8888);Canvas canvas = new Canvas(output);final Paint paint = new Paint();final Rect rect = new Rect(0, 0, width, height);final RectF rectF = new RectF(rect);final float roundPx = 200;paint.setAntiAlias(true);canvas.drawARGB(0, 0, 0, 0);paint.setColor(Color.BLACK);canvas.drawRoundRect(rectF, roundPx, roundPx, paint);paint.setXfermode(new PorterDuffXfermode(PorterDuff.Mode.SRC_IN));final Rect src = new Rect(0, 0, width, bitmap.getHeight());canvas.drawBitmap(bitmap, src, rect, paint);return output;} catch (Exception e) {e.printStackTrace();return bitmap;}}
final Bitmap roundBitmap = Util.getRoundedCornerBitmap(bitmap);
mImageView4.setImageBitmap(roundBitmap);

方法3: 使用BitmapShader带边框的圆形照片

public static Bitmap getRoundBitmapByShader(Bitmap bitmap, int outWidth, int outHeight, int radius, int boarder) {if (bitmap == null) {return null;}int width = bitmap.getWidth();int height = bitmap.getHeight();float widthScale = outWidth * 1f / width;float heightScale = outHeight * 1f / height;Matrix matrix = new Matrix();matrix.setScale(widthScale, heightScale);//创建输出的bitmapBitmap desBitmap = Bitmap.createBitmap(outWidth, outHeight, Bitmap.Config.ARGB_8888);//创建canvas并传入desBitmap，这样绘制的内容都会在desBitmap上Canvas canvas = new Canvas(desBitmap);Paint paint = new Paint(Paint.ANTI_ALIAS_FLAG);//创建着色器BitmapShader bitmapShader = new BitmapShader(bitmap, Shader.TileMode.CLAMP, Shader.TileMode.CLAMP);//给着色器配置matrixbitmapShader.setLocalMatrix(matrix);paint.setShader(bitmapShader);//创建矩形区域并且预留出borderRectF rect = new RectF(boarder, boarder, outWidth - boarder, outHeight - boarder);//把传入的bitmap绘制到圆角矩形区域内canvas.drawRoundRect(rect, radius, radius, paint);if (boarder > 0) {//绘制boarderPaint boarderPaint = new Paint(Paint.ANTI_ALIAS_FLAG);boarderPaint.setColor(Color.BLACK);boarderPaint.setStyle(Paint.Style.STROKE);boarderPaint.setStrokeWidth(boarder);canvas.drawRoundRect(rect, radius, radius, boarderPaint);}return desBitmap;}
final Bitmap roundBitmap1 = Util.getRoundBitmapByShader(bitmap, 800, 800, 400, 50);
mImageView5.setImageBitmap(roundBitmap1);

方法4: 使用CareView使用圆角

<android.support.v7.widget.CardViewandroid:layout_width="300dp"android:layout_height="300dp"app:cardBackgroundColor="#1ac"app:cardCornerRadius="12dp"app:cardElevation="0dp"app:cardPreventCornerOverlap="false"><ImageViewandroid:id="@+id/iv6"android:layout_width="300dp"android:layout_height="300dp"android:scaleType="centerCrop" /></android.support.v7.widget.CardView>