如果您希望将图像切割成圆形显示，可以这样做

public static Bitmap getCircularBitmap(Bitmap bitmap) {
        Bitmap output;

        if (bitmap.getWidth() > bitmap.getHeight()) {
            output = Bitmap.createBitmap(bitmap.getHeight(), bitmap.getHeight(), Bitmap.Config.ARGB_8888);
        } else {
            output = Bitmap.createBitmap(bitmap.getWidth(), bitmap.getWidth(), Bitmap.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());

        float r = 0;

        if (bitmap.getWidth() > bitmap.getHeight()) {
            r = bitmap.getHeight() / 2;
        } else {
            r = bitmap.getWidth() / 2;
        }

        paint.setAntiAlias(true);
        canvas.drawARGB(0, 0, 0, 0);
        paint.setColor(color);
        canvas.drawCircle(r, r, r, paint);
        paint.setXfermode(new PorterDuffXfermode(PorterDuff.Mode.SRC_IN));
        canvas.drawBitmap(bitmap, rect, rect, paint);
        return output;
    }

另一种不使用任何库的方法是使用ImageFilterView，并设置视图的圆百分比将使圆

app: roundPercent =“1”

  <androidx.constraintlayout.utils.widget.ImageFilterView
        android:id="@+id/ivProfile"
        android:layout_width="150dp"
        android:layout_height="150dp"
        android:src="@drawable/custom_button_1"
        app:roundPercent="1"
        android:scaleType="fitXY"
        app:layout_constraintTop_toTopOf="parent"
        app:layout_constraintStart_toStartOf="parent"
        app:layout_constraintEnd_toEndOf="parent"
        app:layout_constraintBottom_toTopOf="@+id/etName"/>

最佳解决方案https://www.youtube.com/watch?v=0MHoNU7ytaw 卡视图的宽度和高度决定了它所包含图像的大小设置如下:

向Gradle添加依赖项(模块) 将xml代码添加到activity.xml或fragment.xml文件中

    implementation 'androidx.cardview:cardview:1.0.0'

   <androidx.cardview.widget.CardView
      android:layout_width="300dp"
      android:layout_height="270dp"
      android:layout_gravity="center"
      app:cardCornerRadius="150dp"
      app:cardBackgroundColor="@color/trans"
      >
    <ImageView
        android:id="@+id/resultImage"
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        android:src="@drawable/congrats"
        android:layout_gravity="center">

    </ImageView>


  </androidx.cardview.widget.CardView>```

只需使用这段简单的代码: 首先添加依赖项:

implementation 'de.hdodenhof:circleimageview:2.2.0'

然后在XML布局中添加以下代码

<de.hdodenhof.circleimageview.CircleImageView xmlns:app="http://schemas.android.com/apk/res-auto"
                                        android:id="@+id/Imgshaligram"
                                        android:layout_width="96dp"
                                        android:layout_height="96dp"
                                        android:src="@drawable/shaligram"
                                        app:civ_border_color="#d1b1b1"

                                        android:foregroundGravity="center"/>

2021年更新:使用Glide v4 CircleCrop参见https://bumptech.github.io/glide/doc/generatedapi.html

    implementation 'com.github.bumptech.glide:glide:4.11.0'
    annotationProcessor 'com.github.bumptech.glide:compiler:4.11.0'

XML

<ImageView
    android:id="@+id/vinyl"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:ignore="ContentDescription" />

在代码中

    Glide.with(this)
            .load("https://images.pexels.com/photos/3828241/pexels-photo-3828241.jpeg")
            .transform(CircleCrop())
            .into(rootView.findViewById<ImageView>(R.id.vinyl))

你可以简单地使用AndroidX ImageFilterView。

 <androidx.constraintlayout.utils.widget.ImageFilterView
        android:layout_width="48dp"
        android:layout_height="48dp"
        android:layout_marginStart="@dimen/margin_medium"
        android:layout_marginBottom="@dimen/margin_medium"
        android:background="@color/white"
        android:padding="@dimen/margin_small"
        app:layout_constraintBottom_toBottomOf="parent"
        app:layout_constraintStart_toStartOf="parent"
        app:roundPercent="1"
        app:srcCompat="@drawable/ic_gallery" />