自定義的class 

FilletImageView.java

public class FilletImageView extends AppCompatImageView {

    float width, height;

    public FilletImageView(Context context) {
        this(context, null);
        init(context, null);
    }

    public FilletImageView(Context context, AttributeSet attrs) {
        this(context, attrs, 0);
        init(context, attrs);
    }

    public FilletImageView(Context context, AttributeSet attrs, int defStyleAttr) {
        super(context, attrs, defStyleAttr);
        init(context, attrs);
    }

    private void init(Context context, AttributeSet attrs) {
        if (Build.VERSION.SDK_INT < 18) {
            setLayerType(View.LAYER_TYPE_SOFTWARE, null);
        }
    }

    @Override
    protected void onLayout(boolean changed, int left, int top, int right, int bottom) {
        super.onLayout(changed, left, top, right, bottom);
        width = getWidth();
        height = getHeight();
    }

    @Override
    protected void onDraw(Canvas canvas) {
        if (width >= 12 && height > 12) {
            Path path = new Path();
            //四個圓角
            path.moveTo(12, 0);
            path.lineTo(width - 12, 0);
            path.quadTo(width, 0, width, 12);
            path.lineTo(width, height - 12);
            path.quadTo(width, height, width - 12, height);
            path.lineTo(12, height);
            path.quadTo(0, height, 0, height - 12);
            path.lineTo(0, 12);
            path.quadTo(0, 0, 12, 0);

            canvas.clipPath(path);
        }
        super.onDraw(canvas);
    }


}

呼叫的方法：

<com.zhiyin.zhiyinapplication.FilletImageView
    android:layout_width="65dp"
    android:layout_height="65dp"
    android:scaleType="fitXY"
    android:src="@drawable/bankbg"/>

然後看一下執行的效果圖