在Android中,ImageView默认是一个矩形。如何使它成为一个圆角矩形(剪辑我的位图的所有4个角为圆角矩形)在ImageView?


请注意,从2021年起,只需使用ShapeableImageView


当前回答

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))             
)

其他回答

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;
 }

}

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);

它可以很容易地完成下面的形状。将其作为src添加到图像中。 如果你想删除边界,只需添加你的背景颜色的边界 :-)

<?xml version="1.0" encoding="utf-8"?>
<layer-list xmlns:android="http://schemas.android.com/apk/res/android">
    <item
        android:drawable="@drawable/img_area_one"
        android:bottom="5dp"
        android:left="5dp"
        android:right="5dp"
        android:top="5dp" />

    <item>
        <shape
            android:padding="10dp"
            android:shape="rectangle">
            <corners
                android:topLeftRadius="8dp"
                android:topRightRadius="8dp"
                />
            <stroke
                android:width="5dp"
                android:color="@color/white" />
        </shape>
    </item>
</layer-list> 

试试这个

Bitmap finalBitmap;
        if (bitmap.getWidth() != radius || bitmap.getHeight() != radius)
            finalBitmap = Bitmap.createScaledBitmap(bitmap, radius, radius,
                    false);
        else
            finalBitmap = bitmap;
        Bitmap output = Bitmap.createBitmap(finalBitmap.getWidth(),
                finalBitmap.getHeight(), Config.ARGB_8888);
        Canvas canvas = new Canvas(output);

        final Paint paint = new Paint();
        final Rect rect = new Rect(0, 0, finalBitmap.getWidth(),
                finalBitmap.getHeight());

        paint.setAntiAlias(true);
        paint.setFilterBitmap(true);
        paint.setDither(true);
        canvas.drawARGB(0, 0, 0, 0);
        paint.setColor(Color.parseColor("#BAB399"));
        canvas.drawCircle(finalBitmap.getWidth() / 2 + 0.7f,
                finalBitmap.getHeight() / 2 + 0.7f,
                finalBitmap.getWidth() / 2 + 0.1f, paint);
        paint.setXfermode(new PorterDuffXfermode(
                android.graphics.PorterDuff.Mode.SRC_IN));
        canvas.drawBitmap(finalBitmap, rect, rect, paint);

        return output;