自定义实现圆头像

<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"
    tools:context="com.bwei.imagecircle.MainActivity"
    android:background="#f0f">

    <ImageView  
        android:layout_width="82.0dip"  
        android:layout_height="82.0dip"  
        android:layout_centerInParent="true"  
        android:contentDescription="@null"/>  

    <com.bwei.imagecircle.CircularImage  
        android:id="@+id/cover_user_photo"  
        android:layout_width="74.0dip"  
        android:layout_height="74.0dip"  
        android:layout_centerInParent="true" />  
RelativeLayout>

package com.example.imagecircle;
import android.content.Context;
import android.graphics.Bitmap;
import android.graphics.Canvas;
import android.graphics.Paint;
import android.graphics.PorterDuff;
import android.graphics.PorterDuffXfermode;
import android.graphics.Xfermode;
import android.graphics.drawable.Drawable;
import android.util.AttributeSet;
import android.widget.ImageView;

public abstract class MaskedImage extends ImageView{

     private static final Xfermode MASK_XFERMODE;  
        private Bitmap mask;  
        private Paint paint;  

        static {  
            PorterDuff.Mode localMode = PorterDuff.Mode.DST_IN;  
            MASK_XFERMODE = new PorterDuffXfermode(localMode);  
        }  

        public MaskedImage(Context paramContext) {  
            super(paramContext);  
        }  

        public MaskedImage(Context paramContext, AttributeSet paramAttributeSet) {  
            super(paramContext, paramAttributeSet);  
        }  

        public MaskedImage(Context paramContext, AttributeSet paramAttributeSet, int paramInt) {  
            super(paramContext, paramAttributeSet, paramInt);  
        }  

        public abstract Bitmap createMask();  

        protected void onDraw(Canvas paramCanvas) {  
            Drawable localDrawable = getDrawable();  
            if (localDrawable == null)  
                return;  
            try {  
                if (this.paint == null) {  
                    Paint localPaint1 = new Paint();  
                    this.paint = localPaint1;  
                    this.paint.setFilterBitmap(false);  
                    Paint localPaint2 = this.paint;  
                    Xfermode localXfermode1 = MASK_XFERMODE;  
                    @SuppressWarnings("unused")  
                    Xfermode localXfermode2 = localPaint2.setXfermode(localXfermode1);  
                }  
                float f1 = getWidth();  
                float f2 = getHeight();  
                int i = paramCanvas.saveLayer(0.0F, 0.0F, f1, f2, null, 31);  
                int j = getWidth();  
                int k = getHeight();  
                localDrawable.setBounds(0, 0, j, k);  
                localDrawable.draw(paramCanvas);  
                if ((this.mask == null) || (this.mask.isRecycled())) {  
                    Bitmap localBitmap1 = createMask();  
                    this.mask = localBitmap1;  
                }  
                Bitmap localBitmap2 = this.mask;  
                Paint localPaint3 = this.paint;  
                paramCanvas.drawBitmap(localBitmap2, 0.0F, 0.0F, localPaint3);  
                paramCanvas.restoreToCount(i); 
                return;  
            } catch (Exception localException){  
                StringBuilder localStringBuilder = new StringBuilder()  
                        .append("Attempting to draw with recycled bitmap. View ID = ");  
                System.out.println("localStringBuilder=="+localStringBuilder);  
            }  
        }  

}

package com.example.imagecircle;
import android.content.Context;
import android.graphics.Bitmap;
import android.graphics.Canvas;
import android.graphics.Paint;
import android.graphics.RectF;
import android.util.AttributeSet;

public class CircularImage extends MaskedImage{

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

        public CircularImage(Context paramContext, AttributeSet paramAttributeSet) {  
            super(paramContext, paramAttributeSet);  
        }  

        public CircularImage(Context paramContext, AttributeSet paramAttributeSet, int paramInt) {  
            super(paramContext, paramAttributeSet, paramInt);  
        }  

        public Bitmap createMask(){  
            int i = getWidth();  
            int j = getHeight();  
            Bitmap.Config localConfig = Bitmap.Config.ARGB_8888;  
            Bitmap localBitmap = Bitmap.createBitmap(i, j, localConfig);  
            Canvas localCanvas = new Canvas(localBitmap);  
            Paint localPaint = new Paint(1);  
            localPaint.setColor(-16777216);  
            float f1 = getWidth();  
            float f2 = getHeight();  
            RectF localRectF = new RectF(0.0F, 0.0F, f1, f2);  
            localCanvas.drawOval(localRectF, localPaint);  
            return localBitmap;  
        }  

}

package com.example.imagecircle;
import android.app.Activity;
import android.os.Bundle;
import android.view.Menu;
import android.view.MenuItem;
import android.view.View;
import android.view.View.OnClickListener;
import android.widget.Toast;
public class MainActivity extends Activity {
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        CircularImage cover_user_photo = (CircularImage) findViewById(R.id.cover_user_photo);  
        cover_user_photo.setImageResource(R.drawable.aa);  
    }
}