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

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:

其他回答

您应该扩展ImageView并绘制自己的圆角矩形。

如果你想在图像周围添加一个框架,你也可以在布局中将圆形框架叠加在图像视图的顶部。

例如,通过使用FrameLayout将帧叠加到原始图像上。FrameLayout的第一个元素将是你想要显示的图像。然后添加另一个ImageView与框架。第二个ImageView将显示在原始ImageView的顶部,因此Android将在原始ImageView上方绘制它的内容。

尝试材质组件库并使用ShapeableImageView。 大概是这样的:

Java:

imageView=new ShapeableImageView(context);
imageView.setShapeAppearanceModel(
        imageView.getShapeAppearanceModel()
                 .toBuilder()
                 .setAllCornerSizes(20)
                 .build());

芬兰湾的科特林:

val imageView = ShapeableImageView(context)
imageView.setShapeAppearanceModel(
        imageView.getShapeAppearanceModel()
                 .toBuilder()
                 .setAllCornerSizes(20f)
                 .build())

    /**
 * Background Async task to load user profile picture from url
 */
private class LoadProfileImage extends AsyncTask<String, Void, RoundedBitmapDrawable> {
    ImageView profileImageView;

    public LoadProfileImage(ImageView profileImageView) {
        this.profileImageView = profileImageView;
    }

    protected RoundedBitmapDrawable doInBackground(String... urls) {
        String photoUrl = urls[0];
        RoundedBitmapDrawable profileRoundedDrawable = null;
        try {
            InputStream inputStream = new java.net.URL(photoUrl).openStream();
            Resources res = getResources();

            profileRoundedDrawable = RoundedBitmapDrawableFactory.create(res, inputStream);
            profileRoundedDrawable.setCircular(true);
        } catch (Exception e) {
            Log.e("Error", e.getMessage());
            e.printStackTrace();
        }
        return profileRoundedDrawable;
    }

    protected void onPostExecute(RoundedBitmapDrawable result) {
        profileImageView.setImageDrawable(result);
    }
}

为了Glide 4.x.x

使用下面的简单代码

Glide
  .with(context)
  .load(uri)
  .apply(
      RequestOptions()
        .circleCrop())
  .into(imageView)

让你的ImageView像这样:

<com.example..CircularImageView
    android:id="@+id/profile_image_round_corner"
    android:layout_width="80dp"
    android:layout_height="80dp"
    android:scaleType="fitCenter"
    android:padding="2dp"
    android:background="@null"
    android:adjustViewBounds="true"
    android:layout_centerInParent="true"
    android:src="@drawable/dummy"
    />

并创建一个类:

package com.example;

import java.util.Formatter.BigDecimalLayoutForm;

import android.content.Context;
import android.graphics.Bitmap;
import android.graphics.Canvas;
import android.graphics.Color;
import android.graphics.Paint;
import android.graphics.PorterDuff.Mode;
import android.graphics.PorterDuffXfermode;
import android.graphics.Rect;
import android.graphics.drawable.BitmapDrawable;
import android.graphics.drawable.Drawable;
import android.util.AttributeSet;
import android.widget.ImageView;

public class CircularImageView extends ImageView {

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

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

    public CircularImageView(Context context, AttributeSet attrs, int defStyle) {
        super(context, attrs, defStyle);
    }

    @Override
    protected void onDraw(Canvas canvas) {

        Drawable drawable = getDrawable();

        if (drawable == null) {
            return;
        }

        if (getWidth() == 0 || getHeight() == 0) {
            return;
        }
        Bitmap b = ((BitmapDrawable) drawable).getBitmap();
        Bitmap bitmap = b.copy(Bitmap.Config.ARGB_8888, true);

        int w = getWidth(), h = getHeight();

        Bitmap roundBitmap = getRoundBitmap(bitmap, w);
        canvas.drawBitmap(roundBitmap, 0, 0, null);

    }

    public static Bitmap getRoundBitmap(Bitmap bmp, int radius) {
        Bitmap sBmp;

        if (bmp.getWidth() != radius || bmp.getHeight() != radius) {
            float smallest = Math.min(bmp.getWidth(), bmp.getHeight());
            float factor = smallest / radius;
            sBmp = Bitmap.createScaledBitmap(bmp, (int)(bmp.getWidth() / factor), (int)(bmp.getHeight() / factor), false);
        } else {
            sBmp = bmp;
        }

        Bitmap output = Bitmap.createBitmap(radius, radius, Bitmap.Config.ARGB_8888);
        Canvas canvas = new Canvas(output);
        final int color = 0xffa19774;
        final Paint paint = new Paint();
        final Rect rect = new Rect(0, 0, radius, radius);
        paint.setAntiAlias(true);
        paint.setFilterBitmap(true);
        paint.setDither(true);
        canvas.drawARGB(0, 0, 0, 0);
        paint.setColor(Color.parseColor("#BAB399"));
        canvas.drawCircle(radius / 2 + 0.7f,
                radius / 2 + 0.7f, radius / 2 + 0.1f, paint);
        paint.setXfermode(new PorterDuffXfermode(Mode.SRC_IN));
        canvas.drawBitmap(sBmp, rect, rect, paint);

        return output;
    }

}