prevent partial overlapping of shape drawable stroke

问题

Is there any way to prevent partial overlapping of the stroke on the shape drawable. I prefer to overlap the stroke completely on the borders of the shape.

Here is my xml

<?xml version="1.0" encoding="utf-8"?>
<shape xmlns:android="http://schemas.android.com/apk/res/android"
    android:shape="rectangle">
    <padding
        android:bottom="0dp"
        android:top="0dp"
        android:left="0dp"
        android:right="0dp" />
    <solid android:color="@color/green" />
    <stroke android:color="@color/red_50"
        android:width="20dp"
        android:dashGap="2dp"
        android:dashWidth="10dp" />
</shape>

colors.xml

<color name="green">#0f0</color>
<color name="red_50">#8f00</color>

And here is what is achieved

As you can see that the stroke is overlapping the solid part by 50% but I want it to be 100%.

回答1:

Try to divide it into two shapes - one for stroke and one for rectangle. In this solution I manipulate size of rectangle so that I can change its relation with borders.

<?xml version="1.0" encoding="utf-8"?>
<layer-list xmlns:android="http://schemas.android.com/apk/res/android">

    <item
        android:bottom="@dimen/offset"
        android:left="@dimen/offset"
        android:right="@dimen/offset"
        android:top="@dimen/offset">

        <shape android:shape="rectangle">
            <solid android:color="@color/green" />
        </shape>

    </item>

    <item>

        <shape android:shape="rectangle">
            <stroke
                android:width="20dp"
                android:color="@color/red_50"
                android:dashGap="2dp"
                android:dashWidth="10dp" />
        </shape>

    </item>

</layer-list>

You can adjust the offset to get outer or inner stroke.

These values come from difference of size of transparent rectangle (stroke layer) and the green one. In your case they will be 20dp or none.

来源：https://stackoverflow.com/questions/40169488/prevent-partial-overlapping-of-shape-drawable-stroke