通过自定义选择器的 ListView 项目背景 [英] ListView item background via custom selector

问题描述

是否可以通过列表选择器为每个 Listview 项目应用自定义背景?

Is it possible to apply a custom background to each Listview item via the list selector?

默认选择器为 state_focused="false" 情况指定了 @android:color/transparent，但将其更改为某些自定义 drawable 不会影响不没有被选中.Romain Guy 似乎建议在这个答案中这是可能的.

The default selector specifies @android:color/transparent for the state_focused="false" case, but changing this to some custom drawable doesn't affect items that aren't selected. Romain Guy seems to suggest in this answer that this is possible.

我目前通过在每个视图上使用自定义背景并在项目被选中/聚焦/显示选择器时隐藏它来实现相同的效果，但将所有这些都定义在一处.

I'm currently achieving the same affect by using a custom background on each view and hiding it when the item is selected/focused/whatever so the selector is shown, but it'd be more elegant to have this all defined in one place.

作为参考，这是我用来尝试使其工作的选择器:

For reference, this is the selector I'm using to try and get this working:

<selector xmlns:android="http://schemas.android.com/apk/res/android">

    <item android:state_focused="false"
        android:drawable="@drawable/list_item_gradient" />

    <!-- Even though these two point to the same resource, have two states so the drawable will invalidate itself when coming out of pressed state. -->
    <item android:state_focused="true" android:state_enabled="false"
        android:state_pressed="true"
        android:drawable="@drawable/list_selector_background_disabled" />
    <item android:state_focused="true" android:state_enabled="false"
        android:drawable="@drawable/list_selector_background_disabled" />

    <item android:state_focused="true" android:state_pressed="true"
        android:drawable="@drawable/list_selector_background_transition" />
    <item android:state_focused="false" android:state_pressed="true"
        android:drawable="@drawable/list_selector_background_transition" />

    <item android:state_focused="true"
        android:drawable="@drawable/list_selector_background_focus" />

</selector>

这就是我设置选择器的方式:

And this is how I'm setting the selector:

<ListView
    android:id="@android:id/list"
    android:layout_width="fill_parent"
    android:layout_height="fill_parent"
    android:listSelector="@drawable/list_selector_background" />    

在此先感谢您的帮助！

推荐答案

我自己也为此感到沮丧，终于解决了.正如 Romain Guy 暗示的那样，您必须使用另一个状态 "android:state_selected".为列表项的背景使用状态可绘制，并为列表的 listSelector 使用不同的状态可绘制:

I've been frustrated by this myself and finally solved it. As Romain Guy hinted to, there's another state, "android:state_selected", that you must use. Use a state drawable for the background of your list item, and use a different state drawable for listSelector of your list:

list_row_layout.xml:

list_row_layout.xml:

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout 
    xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="fill_parent"
    android:layout_height="?android:attr/listPreferredItemHeight"
    android:background="@drawable/listitem_background"
    >
...
</LinearLayout>

listitem_background.xml:

listitem_background.xml:

<?xml version="1.0" encoding="utf-8"?>
<selector xmlns:android="http://schemas.android.com/apk/res/android">
    <item android:state_selected="true" android:drawable="@color/android:transparent" />
    <item android:drawable="@drawable/listitem_normal" />
</selector>

layout.xml 包含 ListView:

layout.xml that includes the ListView:

...
<ListView 
   android:layout_width="fill_parent"
   android:layout_height="wrap_content"
   android:listSelector="@drawable/listitem_selector"
   />
...

listitem_selector.xml:

listitem_selector.xml:

<?xml version="1.0" encoding="utf-8"?>
<selector xmlns:android="http://schemas.android.com/apk/res/android">
    <item android:state_pressed="true" android:drawable="@drawable/listitem_pressed" />
    <item android:state_focused="true" android:drawable="@drawable/listitem_selected" />
</selector>

这篇关于通过自定义选择器的 ListView 项目背景的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！