自定义圆角

package test.bwie.com.yuanjiao;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.Rect;import android.graphics.drawable.BitmapDrawable;import android.graphics.drawable.Drawable;import android.support.annotation.Nullable;import android.util.AttributeSet;import android.widget.ImageView;/** * Created by Shinelon on 2017/12/1. */public class XCRoundImageView extends ImageView{    private Paint paint;    public XCRoundImageView(Context context) {        super(context,null);    }    public XCRoundImageView(Context context, @Nullable AttributeSet attrs) {        super(context, attrs,0);    }    public XCRoundImageView(Context context, @Nullable AttributeSet attrs, int defStyleAttr) {        super(context, attrs, defStyleAttr);        paint = new Paint();    }    @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);        }    }    private Bitmap getCircleBitmap(Bitmap bitmap, int pixels) {        Bitmap output = Bitmap.createBitmap(bitmap.getWidth(),                bitmap.getHeight(), Bitmap.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(PorterDuff.Mode.SRC_IN));        canvas.drawBitmap(bitmap, rect, rect, paint);        return output;    }}

//布局文件中

<test.bwie.com.yuanjiao.RoundAngleImageView    android:layout_width="100dp"    android:layout_height="100dp"    android:layout_centerInParent="true"    android:layout_marginLeft="2dp"    app:roundWidth="30dp"    app:roundHeight="30dp"    android:id="@+id/yj"  android:background="#0f0"    />