android试图圆位图角

Question

我有一个 imageView，我正在尝试创建圆角，尝试了这篇文章中的所有解决方案:How to make an ImageView with rounded corners?但没有任何效果..这是我的 XML

    <RelativeLayout
    android:id="@+id/RL_ImageHolder"
    android:layout_width="150dp"
    android:layout_height="180dp"
    android:layout_alignBottom="@+id/relativeLayout2"
    android:layout_alignParentLeft="true"
    android:layout_alignTop="@+id/relativeLayout2"
    android:layout_marginLeft="10dp" >

    <ImageView
        android:id="@+id/imgPreview"
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        android:layout_centerHorizontal="true"
        android:layout_centerVertical="true"
        android:contentDescription="Preview"

         />
</RelativeLayout>

这就是我使用上面链接的帖子中提到的方法设置 ImageView 的方式:

  byteArray = extras.getByteArray("picture");
    if (byteArray != null) {
        bmp = BitmapFactory.decodeByteArray(byteArray, 0, byteArray.length);
        preview.setScaleType(ScaleType.CENTER_CROP);
        preview.setImageBitmap(getRoundedCornerBitmap(bmp));

图像设置正确，但它仍然是一个矩形.. 知道为什么它不起作用吗？

编辑: 刚刚发现仅当包含图像的布局具有固定的宽度/高度时才行不通。必须考虑如何管理它。谢谢大家

Answer 1

尝试使用下面的代码 fragment :

public static Bitmap GetCurveImage(Bitmap bitmap) {
        // Bitmap myCoolBitmap = ... ; // <-- Your bitmap you
        // want rounded
        int w = bitmap.getWidth(), h = bitmap.getHeight();

        // We have to make sure our rounded corners have an
        // alpha channel in most cases
        Bitmap rounder = Bitmap.createBitmap(w, h, Bitmap.Config.ARGB_8888);
        Canvas canvas = new Canvas(rounder);

        // We're going to apply this paint eventually using a
        // porter-duff xfer mode.
        // This will allow us to only overwrite certain pixels.
        // RED is arbitrary. This
        // could be any color that was fully opaque (alpha =
        // 255)
        Paint xferPaint = new Paint(Paint.ANTI_ALIAS_FLAG);
        xferPaint.setColor(Color.RED);

        // We're just reusing xferPaint to paint a normal
        // looking rounded box, the 20.f
        // is the amount we're rounding by.
        canvas.drawRoundRect(new RectF(0, 0, w, h), 5.0f, 5.0f, xferPaint);

        // Now we apply the 'magic sauce' to the paint
        xferPaint.setXfermode(new PorterDuffXfermode(PorterDuff.Mode.DST_IN));

        Bitmap result = Bitmap.createBitmap(bitmap.getWidth(),
                bitmap.getHeight(), Bitmap.Config.ARGB_8888);
        Canvas resultCanvas = new Canvas(result);
        resultCanvas.drawBitmap(bitmap, 0, 0, null);
        resultCanvas.drawBitmap(rounder, 0, 0, xferPaint);

        return result;
    } 

希望对您有所帮助。