这是一个相对较老的问题，但您可以在可绘制文件夹中创建一个圆形边框(假设xml文件将称为circle_border)

<?xml version="1.0" encoding="utf-8"?>
<shape xmlns="http://schemas.android.com/apk/res/android"
    android:shape="oval">

    <solid android:color="@android:color/transparent" />

    <!-- If you want a padding -->
    <padding android:top="4dp" android:left="4dp" android:right="4dp" android:bottom="4dp" />

    <!-- If you want the circle border to have a color -->
    <strong android:width="1dp" android:color="#FFFFFF" />

</shape>

然后你可以使用它作为ImageView的背景

<ImageView
    android:background="@drawable/circle_border"
    <!-- other attributes here -->
/>

下面是最简单的方法之一，使用以下代码:

依赖关系

dependencies {
    ...
    compile 'de.hdodenhof:circleimageview:2.1.0'      // use this or use the latest compile version. In case u get bug.
}

XML代码

<de.hdodenhof.circleimageview.CircleImageView
    xmlns:app="http://schemas.android.com/apk/res-auto"
    android:id="@+id/profile_image"
    android:layout_width="96dp"             //  here u can adjust the width 
    android:layout_height="96dp"            //  here u can adjust the height 
    android:src="@drawable/profile"         //  here u can change the image 
    app:civ_border_width="2dp"              //  here u can adjust the border of the circle.  
    app:civ_border_color="#FF000000"/>      //  here u can adjust the border color

截图:

来源:Circular ImageView GitHub Repository

这是一个相对较老的问题，但您可以在可绘制文件夹中创建一个圆形边框(假设xml文件将称为circle_border)

<?xml version="1.0" encoding="utf-8"?>
<shape xmlns="http://schemas.android.com/apk/res/android"
    android:shape="oval">

    <solid android:color="@android:color/transparent" />

    <!-- If you want a padding -->
    <padding android:top="4dp" android:left="4dp" android:right="4dp" android:bottom="4dp" />

    <!-- If you want the circle border to have a color -->
    <strong android:width="1dp" android:color="#FFFFFF" />

</shape>

然后你可以使用它作为ImageView的背景

<ImageView
    android:background="@drawable/circle_border"
    <!-- other attributes here -->
/>

在glide库和RoundedBitmapDrawableFactory类的帮助下，很容易实现。您可能需要创建圆形占位符映像。

滑翔V4:

Glide.with(context).load(url).apply(RequestOptions.circleCropTransform()).into(imageView);

滑翔V3:

    Glide.with(context)
        .load(imgUrl)
        .asBitmap()
        .placeholder(R.drawable.placeholder)
        .error(R.drawable.placeholder)
        .into(new BitmapImageViewTarget(imgProfilePicture) {
            @Override
            protected void setResource(Bitmap resource) {
                RoundedBitmapDrawable drawable = RoundedBitmapDrawableFactory.create(context.getResources(),
                        Bitmap.createScaledBitmap(resource, 50, 50, false));
                drawable.setCircular(true);
                imgProfilePicture.setImageDrawable(drawable);
            }
        });

对于Picasso RoundedTransformation，这是一个非常好的解决方案，提供了一个额外的选择，在顶部或底部边缘的图像。

另一个想法是使用ImageView的clipToOutline属性。

这是一个布局示例:

<androidx.constraintlayout.widget.ConstraintLayout
    android:layout_width="match_parent"
    android:layout_height="match_parent">

    <!-- Simple view to draw borders for an image,
         borders will be rounded because of the oval-shaped background. -->
    <View
        android:id="@+id/v_border"
        android:layout_width="50dp"
        android:layout_height="50dp"
        android:background="@drawable/shape_border"
        app:layout_constraintStart_toStartOf="parent"
        app:layout_constraintTop_toTopOf="parent" />

    <!-- Image itself: fits the border view, 
         a margin serves as a border width;
         the key point here - is a background shape which will clip the view to its forms. -->
    <ImageView
        android:id="@+id/iv_image"
        android:layout_width="0dp"
        android:layout_height="0dp"
        android:layout_margin="4dp"
        android:background="@drawable/shape_oval"
        android:src="@mipmap/ic_launcher"
        app:layout_constraintBottom_toBottomOf="@+id/v_border"
        app:layout_constraintEnd_toEndOf="@+id/v_border"
        app:layout_constraintStart_toStartOf="@+id/v_border"
        app:layout_constraintTop_toTopOf="@+id/v_border" />

</androidx.constraintlayout.widget.ConstraintLayout>

这是我们的shape_border可绘制对象:

<?xml version="1.0" encoding="utf-8"?>
<shape xmlns:android="http://schemas.android.com/apk/res/android" android:shape="oval">
    <solid android:color="#FF00FF" />
</shape>

和shape_oval drawable:

<?xml version="1.0" encoding="utf-8"?>
<shape xmlns:android="http://schemas.android.com/apk/res/android" android:shape="oval" />

你在代码中唯一要做的就是启用clipToOutline属性:

binding.ivImage.clipToOutline = true

当然，您甚至可以使用一些BindingAdapter来避免这一行代码。

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;
    }