【Android 界面效果44】Android之圆头像实例

十度 Android 2015年12月02日收藏

在很多应用中，我们看到，个人主页里面的头像一般都是圆的，设计成圆的会使整个界面布局变的优雅漂亮。那么，怎么使头像变圆呢？有的人说可以在上面加一个中间为透明圆形的png图，用它来遮盖住头像不就行了嘛，但是png四周始终始终是不透明的，怎么做也达不到如下的效果图的。

下面我们讲讲怎么做成的吧。

首先创建一个继承ImageView的抽象类MaskedImage。让他重写onDraw方法。代码如下

    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);  
            }  
        }  
    }

然后新建一个类CircularImage继承MaskedImage。代码如下：

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;  
    }  
}

新建一个MainActivity，代码如下：

    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.face);  
        }  
    }

其XML布局文件为：

<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"  
        android:gravity="center" >  
      
        <ImageView  
            android:layout_width="82.0dip"  
            android:layout_height="82.0dip"  
            android:layout_centerInParent="true"  
            android:contentDescription="@null"  
            android:src="@drawable/me_head_bg" />  
      
        <com.doublefi123.diary.widget.CircularImage  
            android:id="@+id/cover_user_photo"  
            android:layout_width="74.0dip"  
            android:layout_height="74.0dip"  
            android:layout_centerInParent="true" />  
      
    </RelativeLayout>