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

你可以在你的布局中只使用ImageView,使用滑动,你可以使用这个方法应用圆角。

首先在你的gradle里写上,

compile 'com.github.bumptech.glide:glide:3.7.0'

对于有圆角的图像,

public void loadImageWithCorners(String url, ImageView view) {
    Glide.with(context)
            .load(url)
            .asBitmap()
            .centerCrop()
            .placeholder(R.color.gray)
            .error(R.color.gray)
            .diskCacheStrategy(DiskCacheStrategy.SOURCE)
            .into(new BitmapImageViewTarget(view) {
                @Override
                protected void setResource(Bitmap resource) {
                    RoundedBitmapDrawable circularBitmapDrawable =
                            RoundedBitmapDrawableFactory.create(context.getResources(), resource);
                    circularBitmapDrawable.setCornerRadius(32.0f); // radius for corners
                    view.setImageDrawable(circularBitmapDrawable);
                }
            });
}

调用方法:

loadImageWithCorners("your url","your imageview");

其他回答

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。

下面是一个覆盖imageView的简单示例,然后你也可以在布局设计器中使用它来预览。

public class RoundedImageView extends ImageView {

    public RoundedImageView(Context context) {
        super(context);
    }

    public RoundedImageView(Context context, AttributeSet attrs) {
        super(context, attrs);
    }

    public RoundedImageView(Context context, AttributeSet attrs, int defStyleAttr) {
        super(context, attrs, defStyleAttr);
    }

    @TargetApi(Build.VERSION_CODES.LOLLIPOP)
    public RoundedImageView(Context context, AttributeSet attrs, int defStyleAttr, int defStyleRes) {
        super(context, attrs, defStyleAttr, defStyleRes);
    }

    @Override
    public void setImageDrawable(Drawable drawable) {
        float radius = 0.1f;
        Bitmap bitmap = ((BitmapDrawable) drawable).getBitmap();
        RoundedBitmapDrawable rid = RoundedBitmapDrawableFactory.create(getResources(), bitmap);
        rid.setCornerRadius(bitmap.getWidth() * radius);
        super.setImageDrawable(rid);
    }
}

这是为了快速解决问题。半径用于所有角落,并基于位图宽度的百分比。

我只是覆盖了setImageDrawable,并使用支持v4方法绘制圆角位图。

用法:

<com.example.widgets.RoundedImageView
        android:layout_width="39dp"
        android:layout_height="39dp"
        android:src="@drawable/your_drawable" />

使用imageView和自定义imageView预览:

使用这个得到圆形图像与边界

    public static Bitmap getCircularBitmapWithBorder(Bitmap bitmap, int bordercolor) {
    if (bitmap == null || bitmap.isRecycled()) {
        return null;
    }
    int borderWidth=(int)(bitmap.getWidth()/40);
    final int width = bitmap.getWidth() + borderWidth;
    final int height = bitmap.getHeight() + borderWidth;

    Bitmap canvasBitmap = Bitmap.createBitmap(width, height,
            Bitmap.Config.ARGB_8888);
    BitmapShader shader = new BitmapShader(bitmap, TileMode.CLAMP,
            TileMode.CLAMP);
    Paint paint = new Paint();
    paint.setAntiAlias(true);
    paint.setShader(shader);

    Canvas canvas = new Canvas(canvasBitmap);
    float radius = width > height ? ((float) height) / 2f
            : ((float) width) / 2f;
    canvas.drawCircle(width / 2, height / 2, radius, paint);
    paint.setShader(null);
    paint.setStyle(Paint.Style.STROKE);
    paint.setColor(bordercolor);
    paint.setStrokeWidth(borderWidth);
    canvas.drawCircle(width / 2, height / 2, radius - borderWidth / 2,
            paint);
    return canvasBitmap;
}

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>