Android使用自定义ImageView实现圆形图片效果

package com.xc.xcskin.view;import android.content.Context;import android.graphics.Bitmap;import android.graphics.Bitmap.Config;import android.graphics.Canvas;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;/** * 自定义的圆形ImageView，可以直接当组件在布局中使用。 * @author caizhiming * */public class XCRoundImageView extends ImageView{ private Paint paint ; public XCRoundImageView(Context context) {  this(context,null);  }  public XCRoundImageView(Context context, AttributeSet attrs) {  this(context, attrs,0);  }  public XCRoundImageView(Context context, AttributeSet attrs, int defStyle) {  super(context, attrs, defStyle);  paint = new Paint(); }  /** * 绘制圆形图片 * @author caizhiming */ @Override  protected void onDraw(Canvas canvas) {  Drawable drawable = getDrawable();  if (null != drawable) {  Bitmap bitmap = ((BitmapDrawable) drawable).getBitmap();  Bitmap b = getCircleBitmap(bitmap, 14);  final Rect rectSrc = new Rect(0, 0, b.getWidth(), b.getHeight());  final Rect rectDest = new Rect(0,0,getWidth(),getHeight()); paint.reset();  canvas.drawBitmap(b, rectSrc, rectDest, paint);  } else {  super.onDraw(canvas);  }  }  /** * 获取圆形图片方法 * @param bitmap * @param pixels * @return Bitmap * @author caizhiming */ private Bitmap getCircleBitmap(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 Rect rect = new Rect(0, 0, bitmap.getWidth(), bitmap.getHeight());  paint.setAntiAlias(true);  canvas.drawARGB(0, 0, 0, 0);  paint.setColor(color);  int x = bitmap.getWidth();  canvas.drawCircle(x / 2, x / 2, x / 2, paint);  paint.setXfermode(new PorterDuffXfermode(Mode.SRC_IN));  canvas.drawBitmap(bitmap, rect, rect, paint);  return output;   } } 

<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android" xmlns:tools="http://schemas.android.com/tools" android:layout_width="match_parent" android:layout_height="match_parent" >  <com.xc.xcskin.view.XCRoundImageView android:id="@+id/roundImageView"  android:layout_centerInParent="true"  android:layout_width="200dp"  android:layout_height="200dp" android:src="@drawable/roundimageview" /> </RelativeLayout>