Android dashed divider in ListView

问题:

I'd like to draw dashed dividers for the listview. But I failed. There are a few similar questions in StackOverflow, but none of them fixed my problem.

Here are the steps I create the dashed divider:

• Create a list_divider.html

  <?xml version="1.0" encoding="utf-8"?><layer-list xmlns:android="http://schemas.android.com/apk/res/android"> <item>
      <shape android:shape="line">
          <stroke
              android:color="#ff0000"
              android:dashWidth="10px"
              android:dashGap="10px" />
      </shape>
  </item> </layer-list>
  

• My layout contains the list view

  <ListView
      android:layout_width="wrap_content"
      android:layout_height="wrap_content"
      android:id="@android:id/list"
      android:layout_gravity="center_horizontal"
      android:footerDividersEnabled="true"
      android:divider="@drawable/list_divider"
      android:dividerHeight="1px"/>
  

Then in the preview inside the UI editor, it's like it works:

• 3.But unfortunate it doesn't work in emulator:

Can anybody give me a hint? Thanks.

P.S.: The reason I'm using layer-list is that I may need to draw 2 lines in the future.

回答1:

Its documented here: https://code.google.com/p/android/issues/detail?id=29944

You have 2 options:

• turn off hardware acceleration: android:hardwareAccelerated="false"
• or: listView.setLayerType(View.LAYER_TYPE_SOFTWARE, null) or xml android:layerType="software"

It gave me too a headache!

回答2:

Did you name the drawable realy list_divider.html? Rename it to list_divider.xml. I'm surprised that it works in the UI editor.

A second thing which might have an impact: for the sizing of the divider use dp instead of px as units. In Listview and in divider xml. You never know how much 10 pixel are.