非常感谢第一个回答。下面是修改后的版本，将矩形图像转换为正方形(和圆形)，填充颜色作为参数传递。

public static Bitmap getRoundedBitmap(Bitmap bitmap, int pixels, int color) {

    Bitmap inpBitmap = bitmap;
    int width = 0;
    int height = 0;
    width = inpBitmap.getWidth();
    height = inpBitmap.getHeight();

    if (width <= height) {
        height = width;
    } else {
        width = height;
    }

    Bitmap output = Bitmap.createBitmap(width, height, 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 = 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(inpBitmap, rect, rect, paint);

    return output;
}

罗曼盖伊就在那里。

缩小版如下。

Bitmap bitmap = ((BitmapDrawable) getResources().getDrawable(R.drawable.image)).getBitmap();

Bitmap bitmapRounded = Bitmap.createBitmap(bitmap.getWidth(), bitmap.getHeight(), bitmap.getConfig());
Canvas canvas = new Canvas(bitmapRounded);
Paint paint = new Paint();
paint.setAntiAlias(true);
paint.setShader(new BitmapShader(bitmap, Shader.TileMode.CLAMP, Shader.TileMode.CLAMP));
canvas.drawRoundRect((new RectF(0.0f, 0.0f, bitmap.getWidth(), bitmap.getHeight())), 10, 10, paint);

imageView.setImageBitmap(bitmapRounded);

从材质组件库的1.2.0-alpha03版本开始，有了新的ShapeableImageView。

你可以这样使用:

<com.google.android.material.imageview.ShapeableImageView
    ...
    app:shapeAppearanceOverlay="@style/roundedImageView"
    app:srcCompat="@drawable/ic_image" />

在你的主题。xml:

<style name="roundedImageView" parent="">
    <item name="cornerFamily">rounded</item>
    <item name="cornerSize">8dp</item>
</style>

或通过编程:

float radius = getResources().getDimension(R.dimen.default_corner_radius);
imageView.setShapeAppearanceModel(imageView.getShapeAppearanceModel()
    .toBuilder()
    .setAllCorners(CornerFamily.ROUNDED,radius)
    .build());

使用jetpack compose，您可以使用RoundedCornerShape应用剪辑修饰器:

Image(
    painter = painterResource(R.drawable.xxxx),
    contentDescription = "xxxx",
    contentScale = ContentScale.Crop,            
    modifier = Modifier
        .size(64.dp)
        .clip(RoundedCornerShape(8.dp))             
)

如果你正在使用格莱德图书馆，这将是有帮助的:

Glide.with(getApplicationContext())
     .load(image_url)
     .asBitmap()
     .centerCrop()
     .into(new BitmapImageViewTarget(imageView) {
        @Override
        protected void setResource(Bitmap resource) {
          RoundedBitmapDrawable circularBitmapDrawable =
                       RoundedBitmapDrawableFactory.create(getApplicationContext().getResources(), resource);
          circularBitmapDrawable.setCornerRadius(dpToPx(10));
          circularBitmapDrawable.setAntiAlias(true);
          imageView.setImageDrawable(circularBitmapDrawable);
        }
     });


public int dpToPx(int dp) {
  DisplayMetrics displayMetrics = getApplicationContext().getResources().getDisplayMetrics();
  return Math.round(dp * (displayMetrics.xdpi / DisplayMetrics.DENSITY_DEFAULT));
}

有一个很酷的库可以让你塑造imageviews。

这里有一个例子:

<com.github.siyamed.shapeimageview.mask.PorterShapeImageView
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    app:siShape="@drawable/shape_rounded_rectangle"
    android:src="@drawable/neo"
    app:siSquare="true"/>

形状定义:

<shape android:shape="rectangle" xmlns:android="http://schemas.android.com/apk/res/android">
    <corners
        android:topLeftRadius="18dp"
        android:topRightRadius="18dp"
        android:bottomLeftRadius="18dp"
        android:bottomRightRadius="18dp" />
    <solid android:color="@color/black" />
</shape>

结果:

让你的ImageView像这样:

<com.example..CircularImageView
    android:id="@+id/profile_image_round_corner"
    android:layout_width="80dp"
    android:layout_height="80dp"
    android:scaleType="fitCenter"
    android:padding="2dp"
    android:background="@null"
    android:adjustViewBounds="true"
    android:layout_centerInParent="true"
    android:src="@drawable/dummy"
    />

并创建一个类:

package com.example;

import java.util.Formatter.BigDecimalLayoutForm;

import android.content.Context;
import android.graphics.Bitmap;
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;
import android.widget.ImageView;

public class CircularImageView extends ImageView {

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

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

    public CircularImageView(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 = getRoundBitmap(bitmap, w);
        canvas.drawBitmap(roundBitmap, 0, 0, null);

    }

    public static Bitmap getRoundBitmap(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, Bitmap.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;
    }

}