对我来说，下面的解决方案似乎是最优雅的:

ImageView roundedImageView = new ImageView (getContext());
roundedImageView.setClipToOutline(true);
Bitmap bitmap = AppUtil.decodeSampledBitmapFromResource(new File(valueListItemsView.getImagePath()), width, height);
roundedImageView.setScaleType(ImageView.ScaleType.CENTER_CROP);
roundedImageView.setImageBitmap(bitmap);
roundedImageView.setBackgroundResource(R.drawable.rounded_corner);

而可绘制的rounded_corner.xml的代码是:

<?xml version="1.0" encoding="utf-8"?>
<shape xmlns:android="http://schemas.android.com/apk/res/android">
    <solid android:color="@color/colorAccent" />
    <corners android:radius="24dp" />
</shape>

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;
    }
}

多亏了melanke，你可以使用一个自定义类并创建一个自定义循环ImageView。

import android.content.Context;
import android.graphics.Bitmap;
import android.graphics.Bitmap.Config;
import android.graphics.Canvas;
import android.graphics.Color;
import android.graphics.Paint;
import android.graphics.PorterDuff.Mode;
import android.graphics.PorterDuffXfermode;
import android.graphics.Rect;
import android.graphics.drawable.BitmapDrawable;
import android.graphics.drawable.Drawable;
import android.util.AttributeSet;

public class MLRoundedImageView extends android.support.v7.widget.AppCompatImageView {

    public MLRoundedImageView(Context context) {
        super(context);
    }

    public MLRoundedImageView(Context context, AttributeSet attrs) {
        super(context, attrs);
    }

    public MLRoundedImageView(Context context, AttributeSet attrs, int defStyle) {
        super(context, attrs, defStyle);
    }

    @Override
    protected void onDraw(Canvas canvas) {

        Drawable drawable = getDrawable();

        if (drawable == null) {
            return;
        }

        if (getWidth() == 0 || getHeight() == 0) {
            return;
        }
        Bitmap b = ((BitmapDrawable) drawable).getBitmap();
        Bitmap bitmap = b.copy(Bitmap.Config.ARGB_8888, true);

        int w = getWidth(), h = getHeight();

        Bitmap roundBitmap = getCroppedBitmap(bitmap, w);
        canvas.drawBitmap(roundBitmap, 0, 0, null);

    }

    public static Bitmap getCroppedBitmap(Bitmap bmp, int radius) {
        Bitmap sbmp;

        if (bmp.getWidth() != radius || bmp.getHeight() != radius) {
            float smallest = Math.min(bmp.getWidth(), bmp.getHeight());
            float factor = smallest / radius;
            sbmp = Bitmap.createScaledBitmap(bmp, (int)(bmp.getWidth() / factor), (int)(bmp.getHeight() / factor), false);
        } else {
            sbmp = bmp;
        }

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

        final int color = 0xffa19774;
        final Paint paint = new Paint();
        final Rect rect = new Rect(0, 0, radius, radius);

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

        return output;
    }

}

然后在XML中使用它:

<your.package.name.MLRoundedImageView
..
/>

源

它可以用ShapeableImageView使用ShapeAppearanceOverlay完成:

<com.google.android.material.imageview.ShapeableImageView
    android:id="@+id/avatar"
    android:layout_width="64dp"
    android:layout_height="64dp"
    android:padding="4dp"
    app:shapeAppearance="@style/ShapeAppearanceOverlay.Avatar"/>

其中样式为ShapeAppearanceOverlay。Avatar驻留在res/values/styles.xml中:

<style name="ShapeAppearanceOverlay.Avatar" parent="ShapeAppearance.MaterialComponents.SmallComponent">
    <item name="cornerFamily">rounded</item>
    <item name="cornerSize">50%</item>
</style>

这只需要相等的layout_height和layout_width设置，否则将是一个药丸和没有圆。

芬兰湾的科特林版:

@GlideExtension
object GamersGeekGlideExtension {

    @NonNull
    @JvmStatic
    @GlideOption
    fun roundedCorners(options: BaseRequestOptions<*>, context: Context, cornerRadius: Int): BaseRequestOptions<*> {
        val px =
            (cornerRadius * (context.resources.displayMetrics.xdpi / DisplayMetrics.DENSITY_DEFAULT)).roundToInt()
        return options.transforms(RoundedCorners(px))
    }
}

注意:Glide扩展现在需要BaseRequestOptions而不是RequestOptions。此外，它与@Sir Codesalot答案在kotlin中转换的函数相同。

这不是确切的答案，但它是一个类似的解决方案。它可能会帮助那些和我有同样遭遇的人。

我的图像是一个应用程序logo，它的背景是透明的，我正在应用XML渐变作为图像背景。我在imageView中添加了必要的padding/margin，然后添加了这个作为我的背景:

<?xml version="1.0" encoding="utf-8"?>
<!-- This file defines the gradient used on the background of the main activity. -->
<selector xmlns:android="http://schemas.android.com/apk/res/android">
    <item>
        <shape>
            <gradient
                android:type="linear"
                android:startColor="@color/app_color_light_background"
                android:endColor="@color/app_color_disabled"
                android:angle="90" />

            <!-- Round the top corners. -->
            <corners
                android:topLeftRadius="@dimen/radius_small"
                android:topRightRadius="@dimen/radius_small" />
        </shape>
    </item>
</selector>