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:

你可以使用新的ShapableImageView提供的新版本的Android材料库。

为此，您首先需要在应用程序级别构建中添加以下依赖项。gradle文件

implementation 'com.google.android.material:material:<version>'

另外，确保这个应用程序级别的构建。gradle文件有谷歌的Maven资源库谷歌()如下所示

allprojects {
repositories {
  google()
  jcenter()
}

}

在此之后，您可以引用此资源来实现所需类型或形状的imageview。

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;
    }
}

下面的代码创建一个圆角矩形布局对象，该对象围绕放置在其中的任何子对象绘制圆角矩形。它还演示了如何在不使用布局xml文件的情况下以编程方式创建视图和布局。

package android.example;

import android.app.Activity;
import android.graphics.Color;
import android.os.Bundle;
import android.util.DisplayMetrics;
import android.util.TypedValue;
import android.view.ViewGroup.LayoutParams;
import android.widget.LinearLayout;
import android.widget.TextView;

public class MessageScreen extends Activity {
 /** Called when the activity is first created. */
 @Override
 public void onCreate(Bundle savedInstanceState) {
  super.onCreate(savedInstanceState);
  int mainBackgroundColor = Color.parseColor("#2E8B57");
  int labelTextColor = Color.parseColor("#FF4500");
  int messageBackgroundColor = Color.parseColor("#3300FF");
  int messageTextColor = Color.parseColor("#FFFF00");

  DisplayMetrics metrics = new DisplayMetrics();
  getWindowManager().getDefaultDisplay().getMetrics(metrics);
  float density = metrics.density;
  int minMarginSize = Math.round(density * 8);
  int paddingSize = minMarginSize * 2;
  int maxMarginSize = minMarginSize * 4;

  TextView label = new TextView(this);
  /*
   * The LayoutParams are instructions to the Layout that will contain the
   * View for laying out the View, so you need to use the LayoutParams of
   * the Layout that will contain the View.
   */
  LinearLayout.LayoutParams labelLayoutParams = new LinearLayout.LayoutParams(
    LayoutParams.WRAP_CONTENT, LayoutParams.WRAP_CONTENT);
  label.setLayoutParams(labelLayoutParams);
  label.setTextSize(TypedValue.COMPLEX_UNIT_SP, 18);
  label.setPadding(paddingSize, paddingSize, paddingSize, paddingSize);
  label.setText(R.string.title);
  label.setTextColor(labelTextColor);

  TextView message = new TextView(this);
  RoundedRectangle.LayoutParams messageLayoutParams = new RoundedRectangle.LayoutParams(
 LayoutParams.FILL_PARENT, LayoutParams.WRAP_CONTENT);
  /*
   * This is one of the calls must made to force a ViewGroup to call its
   * draw method instead of just calling the draw method of its children.
   * This tells the RoundedRectangle to put some extra space around the
   * View.
   */
  messageLayoutParams.setMargins(minMarginSize, paddingSize,
    minMarginSize, maxMarginSize);
  message.setLayoutParams(messageLayoutParams);
  message.setTextSize(TypedValue.COMPLEX_UNIT_SP, paddingSize);
  message.setText(R.string.message);
  message.setTextColor(messageTextColor);
  message.setBackgroundColor(messageBackgroundColor);

  RoundedRectangle messageContainer = new RoundedRectangle(this);
  LinearLayout.LayoutParams messageContainerLayoutParams = new LinearLayout.LayoutParams(
    LayoutParams.FILL_PARENT, LayoutParams.WRAP_CONTENT);
  messageContainerLayoutParams.setMargins(paddingSize, 0, paddingSize, 0);
  messageContainer.setLayoutParams(messageContainerLayoutParams);
  messageContainer.setOrientation(LinearLayout.VERTICAL);
  /*
   * This is one of the calls must made to force a ViewGroup to call its
   * draw method instead of just calling the draw method of its children.
   * This tells the RoundedRectangle to color the the exta space that was
   * put around the View as well as the View. This is exterior color of
   * the RoundedRectangle.
   */
  messageContainer.setBackgroundColor(mainBackgroundColor);
  /*
   * This is one of the calls must made to force a ViewGroup to call its
   * draw method instead of just calling the draw method of its children.
   * This is the interior color of the RoundedRectangle. It must be
   * different than the exterior color of the RoundedRectangle or the
   * RoundedRectangle will not call its draw method.
   */
  messageContainer.setInteriorColor(messageBackgroundColor);
  // Add the message to the RoundedRectangle.
  messageContainer.addView(message);

  //
  LinearLayout main = new LinearLayout(this);
  LinearLayout.LayoutParams mainLayoutParams = new LinearLayout.LayoutParams(
    LayoutParams.FILL_PARENT, LayoutParams.WRAP_CONTENT);
  main.setLayoutParams(mainLayoutParams);
  main.setOrientation(LinearLayout.VERTICAL);
  main.setBackgroundColor(mainBackgroundColor);
  main.addView(label);
  main.addView(messageContainer);

  setContentView(main);
 }
}

RoundedRectangle布局对象的类定义如下:

/**
 *  A LinearLayout that draws a rounded rectangle around the child View that was added to it.
 */
package android.example;

import android.app.Activity;
import android.content.Context;
import android.graphics.Canvas;
import android.graphics.Paint;
import android.graphics.Rect;
import android.graphics.RectF;
import android.util.AttributeSet;
import android.util.DisplayMetrics;
import android.widget.LinearLayout;

/**
 * A LinearLayout that has rounded corners instead of square corners.
 * 
 * @author Danny Remington
 * 
 * @see LinearLayout
 * 
 */
public class RoundedRectangle extends LinearLayout {
 private int mInteriorColor;

 public RoundedRectangle(Context p_context) {
  super(p_context);
 }

 public RoundedRectangle(Context p_context, AttributeSet attributeSet) {
  super(p_context, attributeSet);
 }

 // Listener for the onDraw event that occurs when the Layout is drawn.
 protected void onDraw(Canvas canvas) {
  Rect rect = new Rect(0, 0, getWidth(), getHeight());
  RectF rectF = new RectF(rect);
  DisplayMetrics metrics = new DisplayMetrics();
  Activity activity = (Activity) getContext();
  activity.getWindowManager().getDefaultDisplay().getMetrics(metrics);
  float density = metrics.density;
  int arcSize = Math.round(density * 10);

  Paint paint = new Paint();
  paint.setColor(mInteriorColor);

  canvas.drawRoundRect(rectF, arcSize, arcSize, paint);
 }

 /**
  * Set the background color to use inside the RoundedRectangle.
  * 
  * @param Primitive int - The color inside the rounded rectangle.
  */
 public void setInteriorColor(int interiorColor) {
  mInteriorColor = interiorColor;
 }

 /**
  * Get the background color used inside the RoundedRectangle.
  * 
  * @return Primitive int - The color inside the rounded rectangle.
  */
 public int getInteriorColor() {
  return mInteriorColor;
 }

}

因为所有的答案对我来说都太复杂了，只是为了圆角，我想到了另一个解决方案，我认为值得分享，只是XML，以防你在图像周围有一些空间:

创建一个带有透明内容的带边框的形状，如下所示:

<?xml version="1.0" encoding="utf-8"?>
<shape xmlns:android="http://schemas.android.com/apk/res/android"
    android:shape="rectangle">
    <corners 
        android:radius="30dp" />
    <stroke 
        android:color="#ffffffff"
        android:width="10dp" />
</shape> 

然后在RelativeLayout中，你可以先放置你的图像，然后在相同的位置上面的形状与另一个ImageView。封面形状的大小应与边框宽度相等。注意，要取一个较大的角半径，因为外半径已被定义，但内半径是覆盖你的图像。

希望它也能帮助到别人。

根据CQM请求编辑相关布局示例:

<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="match_parent"
    android:layout_height="match_parent" >

    <ImageView
        android:id="@+id/imageToShow"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_alignBottom="@+id/imgCorners"
        android:layout_alignLeft="@+id/imgCorners"
        android:layout_alignRight="@+id/imgCorners"
        android:layout_alignTop="@+id/imgCorners"
        android:background="#ffffff"
        android:contentDescription="@string/desc"
        android:padding="5dp"
        android:scaleType="centerCrop" />

    <ImageView
        android:id="@+id/imgCorners"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:adjustViewBounds="true"
        android:contentDescription="@string/desc"
        android:src="@drawable/corners_white" />

</RelativeLayout>

我认为最简单的解决方法是这样的:-

步骤1 -创建一个形状绘图文件如下所示

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

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

    <corners android:radius="@dimen/dimen_10dp" />

    <stroke
        android:width="1dp"
        android:color="@color/white" />
</shape>

步骤2 -在代码中使用上述绘图。

Drawable drawable = ContextCompat.getDrawable(mActivity, R.drawable.photos_round_shape);
            drawable.mutate().setColorFilter(randomColor, PorterDuff.Mode.SRC_ATOP);
            imageView.setBackground(drawable);
            if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.LOLLIPOP) {
               imageView.setClipToOutline(true);
            }

Glide.with(mContext)
                .setDefaultRequestOptions(getNoAnimationOptions())
                .load(url)
                .into(imageView);

希望这能有所帮助。