Detailed explanation of the use of Androidselector background selector

In developing applications, in many cases it is necessary to design the background of the listview or button control. Here is a summary of the usage of the android selector:
1. Configure the Android selector in the drawable.
Save the following XML file into a .xml file named by yourself (such as item_bg.xml), and place the file in the drawable file. When using the system, use the corresponding according to the status of the list items in the ListView. Background picture.

<?xml version="1.0" encoding="utf-8" ?>
<selector xmlns:android="http://schemas.android.com/apk/res/android">
    <!-- 默认时的背景图片-->
    <item android:drawable="@drawable/pic1" />
    <!-- 没有焦点时的背景图片-->
    <item android:state_window_focused="false" android:drawable="@drawable/pic1" />
    <!-- 非触摸模式下获得焦点并单击时的背景图片-->
    <item android:state_focused="true"  android:state_pressed="true"
       android:drawable="@drawable/pic2" />
    <!-- 触摸模式下单击时的背景图片-->
    <item android:state_focused="false" android:state_pressed="true"
       android:drawable="@drawable/pic3" />
    <!--选中时的图片背景-->
    <item android:state_selected="true" android:drawable="@drawable/pic4" />
    <!--获得焦点时的图片背景-->
    <item android:state_focused="true" android:drawable="@drawable/pic5" />
</selector>

2. Use the above configuration file:
The first method is to configure it in the listview configuration file, the code is as follows: android:listSelector="@drawable/item_bg"
The second method It is to add attributes to the item in the listview. The code is as follows: android:background="@drawable/item_bg"
The third method is to set it in the java code. The code is as follows: Drawable drawable =getResources().getDrawable(R. drawable.item_bg);
ListView.setSelector(drawable);
The display effect of the above setting method is sometimes black, so you need to add the following code to the configuration file: android:cacheColorHint="@android:color/ transparent" makes its background transparent.
Similarly, Button also has some background effects. The following is an attribute explanation:
android:state_selected is to set the effect when selected.
android:state_focused is to set the effect of getting focus.
android:state_pressed is to set the effect of clicking. Effect
android:state_enabled is to set whether to respond to events
The following is a selector used to set the text state in the button. The code is as follows:

<?xmlversion="1.0" encoding="utf-8"?>
<selectorxmlns:android="http://schemas.android.com/apk/res/android">
    <itemandroid:state_selected="true" android:color="#FFF" />
    <itemandroid:state_focused="true" android:color="#FFF" />
    <itemandroid:state_pressed="true" android:color="#FFF" />
    <itemandroid:color="#000" />
</selector>

For more detailed explanations on the use of the Androidselector background selector, please refer to related articles. Follow PHP Chinese website!