Android Studio Preview 未显示 ListView 示例

Question

I'm new to app development, so maybe I just made an obvious mistake. However my problem is, like I mentioned in the title, my preview is not showing the ListView examples (Picture 1 show what I want the preview to show), but when I add an ArrayList and start it on the emulator every thing is displayed correctly.

1 https://i.stack.imgur.com/w4uON.png

2 https://i.stack.imgur.com/6Hneo.png

3 https://imgur.com/sQtBpAo

4 https://imgur.com/a/moT6M4K

Answer 1

In your layout XML (activity_main.xml), you can add the tools:listitem attribute to the ListView to specify a layout to show in the preview. Like this...

<ListView
    android:id="@+id/myListView"
    android:layout_width="0dp"
    android:layout_height="0dp"
    tools:listitem="@layout/item_something"
    ... />

Just replace 'item_something' with the name of the layout you want to use for each item.

PS. When you're in 'Design' mode rather than editing the XML, look for the attributes with a small spanner icon to the left. There are other 'tools' attributes you can use for similar things.