试试这个

Bitmap finalBitmap;
        if (bitmap.getWidth() != radius || bitmap.getHeight() != radius)
            finalBitmap = Bitmap.createScaledBitmap(bitmap, radius, radius,
                    false);
        else
            finalBitmap = bitmap;
        Bitmap output = Bitmap.createBitmap(finalBitmap.getWidth(),
                finalBitmap.getHeight(), Config.ARGB_8888);
        Canvas canvas = new Canvas(output);

        final Paint paint = new Paint();
        final Rect rect = new Rect(0, 0, finalBitmap.getWidth(),
                finalBitmap.getHeight());

        paint.setAntiAlias(true);
        paint.setFilterBitmap(true);
        paint.setDither(true);
        canvas.drawARGB(0, 0, 0, 0);
        paint.setColor(Color.parseColor("#BAB399"));
        canvas.drawCircle(finalBitmap.getWidth() / 2 + 0.7f,
                finalBitmap.getHeight() / 2 + 0.7f,
                finalBitmap.getWidth() / 2 + 0.1f, paint);
        paint.setXfermode(new PorterDuffXfermode(
                android.graphics.PorterDuff.Mode.SRC_IN));
        canvas.drawBitmap(finalBitmap, rect, rect, paint);

        return output;

相当多的答案!

我遵循了一些人也建议的这个例子:http://www.techrepublic.com/article/pro-tip-round-corners-on-an-android-imageview-with-this-hack/

然而，我需要的是一个透明图像后面的彩色圆圈。对于任何有兴趣做同样事情的人…

1)设置FrameLayout的宽度和高度-在我的情况下，图像的大小(50dp)。 2)将带有src = "@drawable/…"的ImageView放在带有图像的ImageView之上。给它一个id，在我的例子中，我叫它iconShape 3) Drawable mask.xml应该是纯色的#ffffffff 4)如果你想在你的代码中动态地改变圆圈的颜色，可以这样做

ImageView iv2 = (ImageView) v.findViewById(R.id.iconShape);
Drawable shape = getResources().getDrawable(R.drawable.mask);
shape.setColorFilter(Color.BLUE, Mode.MULTIPLY);
iv2.setImageDrawable(shape);

对于上面提到的乔治·沃尔特斯二世，我只是把他的答案扩展了一下，以支持不同的圆角。这可以进一步优化(一些目标矩形重叠)，但不是很多。

我知道这个线程有点老了，但它是谷歌上关于如何在Android上圆角ImageViews的查询的顶级结果之一。

/**
 * Use this method to scale a bitmap and give it specific rounded corners.
 * @param context Context object used to ascertain display density.
 * @param bitmap The original bitmap that will be scaled and have rounded corners applied to it.
 * @param upperLeft Corner radius for upper left.
 * @param upperRight Corner radius for upper right.
 * @param lowerRight Corner radius for lower right.
 * @param lowerLeft Corner radius for lower left.
 * @param endWidth Width to which to scale original bitmap.
 * @param endHeight Height to which to scale original bitmap.
 * @return Scaled bitmap with rounded corners.
 */
public static Bitmap getRoundedCornerBitmap(Context context, Bitmap bitmap, float upperLeft,
        float upperRight, float lowerRight, float lowerLeft, int endWidth,
        int endHeight) {
    float densityMultiplier = context.getResources().getDisplayMetrics().density;

    // scale incoming bitmap to appropriate px size given arguments and display dpi
    bitmap = Bitmap.createScaledBitmap(bitmap, 
            Math.round(endWidth * densityMultiplier),
            Math.round(endHeight * densityMultiplier), true);

    // create empty bitmap for drawing
    Bitmap output = Bitmap.createBitmap(
            Math.round(endWidth * densityMultiplier),
            Math.round(endHeight * densityMultiplier), Config.ARGB_8888);

    // get canvas for empty bitmap
    Canvas canvas = new Canvas(output);
    int width = canvas.getWidth();
    int height = canvas.getHeight();

    // scale the rounded corners appropriately given dpi
    upperLeft *= densityMultiplier;
    upperRight *= densityMultiplier;
    lowerRight *= densityMultiplier;
    lowerLeft *= densityMultiplier;

    Paint paint = new Paint();
    paint.setAntiAlias(true);
    paint.setColor(Color.WHITE);

    // fill the canvas with transparency
    canvas.drawARGB(0, 0, 0, 0);

    // draw the rounded corners around the image rect. clockwise, starting in upper left.
    canvas.drawCircle(upperLeft, upperLeft, upperLeft, paint);
    canvas.drawCircle(width - upperRight, upperRight, upperRight, paint);
    canvas.drawCircle(width - lowerRight, height - lowerRight, lowerRight, paint);
    canvas.drawCircle(lowerLeft, height - lowerLeft, lowerLeft, paint);

    // fill in all the gaps between circles. clockwise, starting at top.
    RectF rectT = new RectF(upperLeft, 0, width - upperRight, height / 2);
    RectF rectR = new RectF(width / 2, upperRight, width, height - lowerRight);
    RectF rectB = new RectF(lowerLeft, height / 2, width - lowerRight, height);
    RectF rectL = new RectF(0, upperLeft, width / 2, height - lowerLeft);

    canvas.drawRect(rectT, paint);
    canvas.drawRect(rectR, paint);
    canvas.drawRect(rectB, paint);
    canvas.drawRect(rectL, paint);

    // set up the rect for the image
    Rect imageRect = new Rect(0, 0, width, height);

    // set up paint object such that it only paints on Color.WHITE
    paint.setXfermode(new AvoidXfermode(Color.WHITE, 255, AvoidXfermode.Mode.TARGET));

    // draw resized bitmap onto imageRect in canvas, using paint as configured above
    canvas.drawBitmap(bitmap, imageRect, imageRect, paint);

    return output;
}

对于那些使用Glide和Kotlin的，你可以通过扩展RequestBuilder来实现

fun <T> GlideRequest<T>.roundCorners(cornerRadius: Int) =
    apply(RequestOptions().transform(RoundedCorners(cornerRadius)))

并使用as;

 GlideApp.with(context)
            .load(url)
            .roundCorners(context.resources.getDimension(R.dimen.radius_in_dp).toInt())
            .into(imgView)

您应该扩展ImageView并绘制自己的圆角矩形。

如果你想在图像周围添加一个框架，你也可以在布局中将圆形框架叠加在图像视图的顶部。

例如，通过使用FrameLayout将帧叠加到原始图像上。FrameLayout的第一个元素将是你想要显示的图像。然后添加另一个ImageView与框架。第二个ImageView将显示在原始ImageView的顶部，因此Android将在原始ImageView上方绘制它的内容。

这是相当晚的响应，但对于任何其他人正在寻找这个，您可以执行以下代码手动圆角的图像。

http://www.ruibm.com/?p=184

这不是我的代码，但我用过它，它的工作非常出色。我将它用作ImageHelper类中的一个助手，并对它进行了一点点扩展，以便传入给定图像所需的羽化量。

最终代码如下所示:

package com.company.app.utils;

import android.graphics.Bitmap;
import android.graphics.Canvas;
import android.graphics.Paint;
import android.graphics.PorterDuffXfermode;
import android.graphics.Rect;
import android.graphics.RectF;
import android.graphics.Bitmap.Config;
import android.graphics.PorterDuff.Mode;

public class ImageHelper {
    public static Bitmap getRoundedCornerBitmap(Bitmap bitmap, int pixels) {
        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 = pixels;

        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;
    }
}