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>
源码在此:http://download.csdn.net/detail/dongdong230/8428989 (免费奉献源码)