绘制带圆角的LinearLayout

Question

我正在尝试实现一个使用圆角绘制自己的LinearLayout子类.根据我的研究,我设置setWillNotDraw(false)并覆盖onDraw()在画布上绘制一个圆角矩形:

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

    int sc = canvas.saveLayer(0, 0, getWidth(), getHeight(), drawPaint, Canvas.MATRIX_SAVE_FLAG | Canvas.CLIP_SAVE_FLAG | Canvas.HAS_ALPHA_LAYER_SAVE_FLAG
            | Canvas.FULL_COLOR_LAYER_SAVE_FLAG | Canvas.CLIP_TO_LAYER_SAVE_FLAG);
    canvas.drawRoundRect(bounds, mCornerRadius, mCornerRadius, roundPaint);
    canvas.restoreToCount(sc);
}

哪里:

drawPaint = new Paint(Paint.ANTI_ALIAS_FLAG);
drawPaint.setColor(0xffffffff);
drawPaint.setXfermode(new PorterDuffXfermode(PorterDuff.Mode.DST_IN));

roundPaint = new Paint(Paint.ANTI_ALIAS_FLAG);
roundPaint.setColor(0xffffffff);

DST_IN这里似乎是正确的选择(根据APIDemos示例),但应该是透明的区域(圆形的)具有黑色背景,并且子项的角仍然可见.这是使用Android 4.2.2的Galaxy Nexus的结果:

任何提示？

编辑:这是我想要实现的,抱歉photoshopping的粗糙:)

编辑2:我向GitHub添加了一个可运行的示例项目:https://github.com/venator85/RoundClippingLayout

谢谢 ;)

Answer 1

不太一样:Romain Guy做了一篇关于使用位图着色器裁剪图像边角的博文.不确定是否要扩展同样的东西.

http://www.curious-creature.org/2012/12/11/android-recipe-1-image-with-rounded-corners/

Answer 2

试试这个,

布局:-

<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout 
    xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="match_parent"
    android:layout_height="match_parent">
    <LinearLayout 
        android:id="@+id/linearLayout"
        android:layout_width="300dp"
        android:gravity="center"
        android:layout_height="300dp"
        android:layout_centerInParent="true"
        android:background="@drawable/rounded_edge">
        <TextView
             android:layout_width="wrap_content"
             android:layout_height="wrap_content"
             android:text="foo" />
    </LinearLayout>
</RelativeLayout>

形状(可绘制): - rounded_edge.xml

<shape 
        xmlns:android="http://schemas.android.com/apk/res/android">
            <solid 
                android:color="@android:color/darker_gray">
            </solid>
            <stroke 
                 android:width="0dp" 
                 android:color="#424242">
            </stroke>
            <corners 
                 android:topLeftRadius="100dip"
                 android:topRightRadius="100dip"
                 android:bottomLeftRadius="100dip"
                 android:bottomRightRadius="100dip">
            </corners>
        </shape>

Answer 3

怎么样...

myLayout.setBackgroundResource(R.drawable.my_rounded_drawable);

然后...

my_rounded_drawable.xml

<?xml version="1.0" encoding="utf-8"?>
<selector xmlns:android="http://schemas.android.com/apk/res/android">
    <item>
        <shape>
            <solid android:color="#FFFFFFFF" />
            <stroke android:width="1dip" android:color="#FF000000" />
            <corners android:radius="10dp" />
        </shape>
    </item>
</selector>