它可以很容易地完成下面的形状。将其作为src添加到图像中。 如果你想删除边界，只需添加你的背景颜色的边界 :-)

<?xml version="1.0" encoding="utf-8"?>
<layer-list xmlns:android="http://schemas.android.com/apk/res/android">
    <item
        android:drawable="@drawable/img_area_one"
        android:bottom="5dp"
        android:left="5dp"
        android:right="5dp"
        android:top="5dp" />

    <item>
        <shape
            android:padding="10dp"
            android:shape="rectangle">
            <corners
                android:topLeftRadius="8dp"
                android:topRightRadius="8dp"
                />
            <stroke
                android:width="5dp"
                android:color="@color/white" />
        </shape>
    </item>
</layer-list> 

它可以很容易地完成下面的形状。将其作为src添加到图像中。 如果你想删除边界，只需添加你的背景颜色的边界 :-)

<?xml version="1.0" encoding="utf-8"?>
<layer-list xmlns:android="http://schemas.android.com/apk/res/android">
    <item
        android:drawable="@drawable/img_area_one"
        android:bottom="5dp"
        android:left="5dp"
        android:right="5dp"
        android:top="5dp" />

    <item>
        <shape
            android:padding="10dp"
            android:shape="rectangle">
            <corners
                android:topLeftRadius="8dp"
                android:topRightRadius="8dp"
                />
            <stroke
                android:width="5dp"
                android:color="@color/white" />
        </shape>
    </item>
</layer-list> 

相当多的答案!

我遵循了一些人也建议的这个例子:http://www.techrepublic.com/article/pro-tip-round-corners-on-an-android-imageview-with-this-hack/

然而，我需要的是一个透明图像后面的彩色圆圈。对于任何有兴趣做同样事情的人…

1)设置FrameLayout的宽度和高度-在我的情况下，图像的大小(50dp)。 2)将带有src = "@drawable/…"的ImageView放在带有图像的ImageView之上。给它一个id，在我的例子中，我叫它iconShape 3) Drawable mask.xml应该是纯色的#ffffffff 4)如果你想在你的代码中动态地改变圆圈的颜色，可以这样做

ImageView iv2 = (ImageView) v.findViewById(R.id.iconShape);
Drawable shape = getResources().getDrawable(R.drawable.mask);
shape.setColorFilter(Color.BLUE, Mode.MULTIPLY);
iv2.setImageDrawable(shape);

以下是我的解决方案:

<com.myproject.ui.RadiusCornerImageView
        android:id="@+id/imageViewPhoto"
        android:layout_width="160dp"
        android:layout_height="160dp"
        app:corner_radius_dp="5"
        app:corner_radius_position="top"
        app:layout_constraintLeft_toLeftOf="parent"
        app:layout_constraintRight_toRightOf="parent"
        app:layout_constraintTop_toTopOf="parent" />

在java代码中:

public class RadiusCornerImageView extends android.support.v7.widget.AppCompatImageView {
    private int cornerRadiusDP = 0; // dp
    private int corner_radius_position;

    public RadiusCornerImageView(Context context) {
        super(context);
    }

    public RadiusCornerImageView(Context context, AttributeSet attrs) {
        super(context, attrs);
    }

    public RadiusCornerImageView(Context context, AttributeSet attrs, int defStyle) {
        super(context, attrs, defStyle);
        TypedArray typeArray = context.getTheme().obtainStyledAttributes(attrs, R.styleable.RadiusCornerImageView, 0, 0);
        try {
            cornerRadiusDP = typeArray.getInt(R.styleable.RadiusCornerImageView_corner_radius_dp, 0);
            corner_radius_position = typeArray.getInteger(R.styleable.RadiusCornerImageView_corner_radius_position, 0);
        } finally {
            typeArray.recycle();
        }
    }

    @Override
    protected void onDraw(Canvas canvas) {
        float radiusPx = AndroidUtil.dpToPx(getContext(), cornerRadiusDP);
        Path clipPath = new Path();
        RectF rect = null;
        if (corner_radius_position == 0) { // all
            // round corners on all 4 angles
            rect = new RectF(0, 0, this.getWidth(), this.getHeight());
        } else if (corner_radius_position == 1) {
            // round corners only on top left and top right
            rect = new RectF(0, 0, this.getWidth(), this.getHeight() + radiusPx);

    } else {
        throw new IllegalArgumentException("Unknown corner_radius_position = " + corner_radius_position);
    }
    clipPath.addRoundRect(rect, radiusPx, radiusPx, Path.Direction.CW);
    canvas.clipPath(clipPath);
    super.onDraw(canvas);
 }
}

我知道这个问题已经过时了，但这里有另一种更简单的四舍五入图像的方法:

这是一种编程方法。

创造你的空白……

} public static Bitmap getRoundedCornerBitmap(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 Paint paint = new Paint(); final Rect rect = new Rect(0, 0, bitmap.getWidth(), bitmap.getHeight());
final RectF rectF = new RectF(rect);
final float roundPx = pixels; paint.setAntiAlias(true); 
canvas.drawARGB(0, 0, 0, 0); paint.setColor(color);
canvas.drawRoundRect(rectF, roundPx, roundPx, paint);
paint.setXfermode(new PorterDuffXfermode(PorterDuff.Mode.SRC_IN));
canvas.drawBitmap(bitmap, rect, rect, paint); return output;

加载图像，然后设置圆角

imageview1.setImageResource(R.drawable.yourimage);

Bitmap bm = ((android.graphics.drawable.BitmapDrawable) imageview1.getDrawable()).getBitmap();
imageview1.setImageBitmap(getRoundedCornerBitmap(bm, 30)); 

以30为半径，你会得到这样的结果:

不管我的图像看起来如何，它只是一个放大的小图标

我使用路径在图像画布上只画角。(我需要没有位图内存分配的解决方案)

@Override
protected void onDraw(final Canvas canvas) {
    super.onDraw(canvas);

    if (!hasRoundedCorners()) return;

    mPaint.setStyle(Paint.Style.FILL);
    mPaint.setStrokeWidth(0);

    Path path = new Path();
    path.setFillType(Path.FillType.INVERSE_WINDING);
    path.addRoundRect(new RectF(0, 0, getWidth(), getHeight()), mRadius, mRadius, Path.Direction.CCW);
    canvas.drawPath(path, mPaint);
}

注意，你不应该在onDraw方法中分配任何新对象。此代码是概念验证，不应该在产品代码中这样使用

看到更多: https://medium.com/@przemek.materna/rounded-image-view-no-bitmap-reallocation-11a8b163484d