Android圆形的Imageview

王玲lynn

已于 2022-09-14 12:26:27 修改

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分类专栏： Android 文章标签： imageview 自定义控件

于 2015-03-16 11:09:08 首次发布

本文链接：https://blog.youkuaiyun.com/Metis100/article/details/44302827

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本文介绍了一种自定义的圆形ImageView控件实现方法。该控件能够在Android应用中显示圆形头像等图片，通过继承ImageView并重写onDraw方法来实现圆形裁剪。文章提供了完整的Java代码示例及XML布局文件，方便开发者直接使用。

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圆形imageview自定义控件：‘

package com.wangll.widget;

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

/**
 * 圆形的Imageview
 * 
 * @author wangll
 * 
 */
public class CircularImage extends ImageView {

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

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

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

	@Override
	protected void onDraw(Canvas canvas) {

		Drawable drawable = getDrawable();
		if (null != drawable) {
			Bitmap bitmap = ((BitmapDrawable) drawable).getBitmap();
			if (null != bitmap) {
				Bitmap b = toRoundCorner(bitmap);

				Paint paint = new Paint();
				paint.setAntiAlias(true);
				paint.setFilterBitmap(true);

				canvas.drawBitmap(b, new Rect(0, 0, b.getWidth(), b.getHeight()),
						new Rect(0, 0, this.getWidth(), this.getHeight()), paint);
			}
		} else {
			super.onDraw(canvas);
		}
	}

	private Bitmap toRoundCorner(Bitmap bitmap) {
		Bitmap outBitmap = Bitmap.createBitmap(bitmap.getWidth(), bitmap.getHeight(), Config.ARGB_8888);

		final Paint paint = new Paint();
		paint.setAntiAlias(true);
		paint.setFilterBitmap(true);
		paint.setColor(0xffffffff);

		final Rect rect = new Rect(0, 0, bitmap.getWidth(), bitmap.getHeight());
		final RectF rectF = new RectF(rect);
		final float roundPX = bitmap.getWidth() / 2 < bitmap.getHeight() / 2 ? bitmap.getWidth() : bitmap.getHeight();

		Canvas canvas = new Canvas(outBitmap);
		canvas.drawARGB(0, 0, 0, 0);
		canvas.setDrawFilter(new PaintFlagsDrawFilter(0, Paint.ANTI_ALIAS_FLAG | Paint.FILTER_BITMAP_FLAG));
		canvas.drawRoundRect(rectF, roundPX, roundPX, paint);
		paint.setXfermode(new PorterDuffXfermode(Mode.SRC_IN));
		canvas.drawBitmap(bitmap, rect, rect, paint);

		return outBitmap;
	}
}

xml中直接用

 <com.wangll.widget.CircularImage
               android:id="@+id/mImg_photo"
                android:layout_width="35dp"
                android:layout_height="35dp"
                android:scaleType="centerCrop"
                android:layout_marginRight="9dp"
               android:layout_centerVertical="true"
                android:layout_alignParentRight="true"
                android:src="@drawable/default_head_man" />

图片效果：