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;
    }

这是我设计的最简单的方法。试试这个。

依赖关系

implementation 'androidx.appcompat:appcompat:1.3.0-beta01' implementation 'androidx.cardview:cardview:1.0.0' <android.support.v7.widget.CardView android:layout_width="80dp" android:layout_height="80dp" android:elevation="12dp" android:id="@+id/view2" app:cardCornerRadius="40dp" android:layout_centerHorizontal="true" android:innerRadius="0dp" android:shape="ring" android:thicknessRatio="1.9"> <ImageView android:layout_height="80dp" android:layout_width="match_parent" android:id="@+id/imageView1" android:src="@drawable/YOUR_IMAGE" android:layout_alignParentTop="true" android:layout_centerHorizontal="true"> </ImageView> </android.support.v7.widget.CardView> If you are working on android versions above lollipop <android.support.v7.widget.CardView android:layout_width="80dp" android:layout_height="80dp" android:elevation="12dp" android:id="@+id/view2" app:cardCornerRadius="40dp" android:layout_centerHorizontal="true"> <ImageView android:layout_height="80dp" android:layout_width="match_parent" android:id="@+id/imageView1" android:src="@drawable/YOUR_IMAGE" android:scaleType="centerCrop"/> </android.support.v7.widget.CardView>

添加边界圆ImageView -最新版本

用另一个比内部CardView稍大的CardView包装它，并设置它的背景色，为圆形图像添加边框。你可以增加外部CardView的大小来增加边框的厚度。

<androidx.cardview.widget.CardView
  android:layout_width="155dp"
  android:layout_height="155dp"
  app:cardCornerRadius="250dp"
  app:cardBackgroundColor="@color/white">

    <androidx.cardview.widget.CardView
      android:layout_width="150dp"
      android:layout_height="150dp"
      app:cardCornerRadius="250dp"
      android:layout_gravity="center">

        <ImageView
          android:layout_width="150dp"
          android:layout_height="150dp"
          android:src="@drawable/default_user"
          android:scaleType="centerCrop"/>

   </androidx.cardview.widget.CardView>

 </androidx.cardview.widget.CardView>

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。

我希望这对你有所帮助。

1） 可塑性图像视图

<com.google.android.material.imageview.ShapeableImageView
        android:layout_width="250dp"
        android:layout_height="250dp"
        android:padding="5dp"
        app:strokeWidth="10dp"
        app:strokeColor="@android:color/darker_gray"
        app:shapeAppearanceOverlay="@style/circleImageView"
        android:src="@drawable/profile"
        android:layout_margin="10dp"/>


 Style add here: res/values/styles.xml 
<style name="circleImageView" parent="">
    <item name="cornerFamily">rounded</item>
    <item name="cornerSize">50%</item>
  </style>

完整的描述请查看这里:来源在这里。

2） 圆图像视图

 <de.hdodenhof.circleimageview.CircleImageView
    xmlns:app="http://schemas.android.com/apk/res-auto"
    android:id="@+id/profile_image"
    android:layout_width="96dp"
    android:layout_height="96dp"
    android:src="@drawable/profile"
    app:civ_border_width="2dp"
    app:civ_border_color="#FF000000"/>

别忘了实现:Gradle Scripts > build。gradle (Module: app) >依赖项

     implementation 'de.hdodenhof:circleimageview:3.1.0'   
        

完整的描述请查看这里:来源在这里。

3） 循环图像视图

<com.mikhaellopez.circularimageview.CircularImageView
    android:layout_width="250dp"
    android:layout_height="250dp"
    android:src="@drawable/image"
    app:civ_border_color="#3f51b5"
    app:civ_border_width="4dp"
    app:civ_shadow="true"
    app:civ_shadow_radius="10"
    app:civ_shadow_color="#3f51b5"/>

别忘了实现:Gradle Scripts > build。gradle (Module: app) >依赖项

     implementation 'com.mikhaellopez:circularimageview:4.3.1'   
        

完整的描述请查看这里:来源在这里。

创建一个CustomImageview，然后简单地覆盖它的onDraw()方法如下:

@Override
protected void onDraw(Canvas canvas) {

    float radius = this.getHeight()/2;
    Path path = new Path();
    RectF rect = new RectF(0, 0, this.getWidth(), this.getHeight());
    path.addRoundRect(rect, radius, radius, Path.Direction.CW);
    canvas.clipPath(path);
    super.onDraw(canvas);

}

如果你想要的代码自定义小部件以及:-

CircularImageView.java

import android.content.Context;
import android.content.res.TypedArray;
import android.graphics.Canvas;
import android.graphics.Path;
import android.graphics.RectF;
import android.graphics.drawable.Drawable;
import android.util.AttributeSet;
import android.widget.ImageView;

import androidx.annotation.Nullable;

public class CircularImageView extends ImageView {

    private Drawable image;

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

        init(null, 0);
    }

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

        init(attrs, 0);
    }

    public CircularImageView(Context context, @Nullable AttributeSet attrs, int defStyleAttr) {
        super(context, attrs, defStyleAttr);

        init(attrs, defStyleAttr);
    }

    @Override
    protected void onDraw(Canvas canvas) {

        float radius = this.getHeight()/2;
        Path path = new Path();
        RectF rect = new RectF(0, 0, this.getWidth(), this.getHeight());
        path.addRoundRect(rect, radius, radius, Path.Direction.CW);
        canvas.clipPath(path);
        super.onDraw(canvas);

    }

    private void init(AttributeSet attrs, int defStyle) {
        TypedArray a = Utils.CONTEXT.getTheme().obtainStyledAttributes(attrs, R.styleable.CircularImageView, 0, 0);
        try {
            image = a.getDrawable(R.styleable.CircularImageView_src);
        } finally {
            a.recycle();
        }

        this.setImageDrawable(image);
    }
}

此外，在res/attrs.xml中添加以下代码来创建所需的属性

<declare-styleable name="CircularImageView">
        <attr name="src" format="reference" />
</declare-styleable>

把这个答案贴出来供将来参考。你可以在com.google.android.material:material中使用ShapeableImageView。

<com.google.android.material.imageview.ShapeableImageView
    android:id="@+id/img_launcher_icon"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:layout_centerHorizontal="true"
    android:layout_margin="5dp"
    android:adjustViewBounds="true"
    android:background="@android:color/transparent"
    android:elevation="5dp"
    android:maxWidth="50dp"
    android:maxHeight="50dp"
    android:scaleType="fitXY"
    android:src="@mipmap/ic_launcher"
    app:shapeAppearance="?attr/actionButtonStyle"
    app:shapeAppearanceOverlay="@style/imageViewRounded"
    app:strokeColor="@android:color/white" />

在你的styles.xml中添加imageviewraded样式

<style name="imageViewRounded">
    <item name="cornerFamily">rounded</item>
    <item name="cornerSize">51%</item>
</style>

如果没有添加，可以添加材料设计依赖项。

    implementation 'com.google.android.material:material:1.4.0'

设计是这样的