android background selector selector and usage instructions

Reference http://blog.sina.com.cn/s/blog_4b93170a0100qhwa.html

First, we need to create a drawable xml file in the folder

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

Content selector selector

Then we add a key item in the xml file inside, using auto-complete build, we found that there are a lot item attributes can be set:

<-! Background image at the time of default -> <Item Android: = drawable "@ drawable / pic1" />

<-! Background image when there is no focal point ->
  <Item Android: state_window_focused = "false"
        drawable = "drawable @ / pic1" /: Android>
- <! Gets the focus and the background under a non-touch mode when clicking picture ->
  <Item Android: state_focused = "to true" Android: state_pressed = "to true"    Android: = drawable "@ drawable / pic2" />

<-! Background image when the touch mode, click ->

<-! Picture background when selected ->

<! - picture context in which to get the focus ->

Two . Use xml file:

1. Method a: in listview configuration android: listSelector = "@ drawable /
xxx or listview of item added attribute Android : background =" @ the drawable / XXX "

2. Method Two: . Drawable drawable = getResources () getDrawable (. R.drawable xxx );
ListView.setSelector (drawable); but sometimes this is the case there will be a list of black, you need to add: Android: cacheColorHint = "@ android: color / transparent " make it transparent. Related attributes:

android: state_selected is selected
android: state_focused is to get the focus
android: state_pressed clicking
android: state_enabled is set whether to respond to events , refers to all events

These states may be provided according to the same button of the selector effect. You may be provided selector change button text state.

以下是配置button中的文字效果：
drawable/button_font.xml
<?xml version="1.0" encoding="utf-8"?>
<selector xmlns:android="http://schemas.android.com/apk/res/android">
    <item android:state_selected="true" android:color="#FFF" />
    <item android:state_focused="true" android:color="#FFF" />
    <item android:state_pressed="true" android:color="#FFF" />
    <item android:color="#000" />
</selector>
Button还可以实现更复杂的效果，例如渐变
drawable/button_color.xml
<?xml version="1.0" encoding="utf-8"?>
<selector xmlns:android="http://schemas.android.com/apk/res/android">        /
<item android:state_pressed="true">//定义当button 处于pressed 状态时的形态。
                <shape>

</item>
<item android:state_focused="true">// 定义当button获得 focus时的形态
                 <shape>
                       <gradient android:startColor="#eac100"/>
                        <stroke android:width="2dp" android:color="#333333"  color="#ffffff"/>
                         <corners android:radius="8dp" />
                         <padding android:left="10dp" android:top="10dp"
                                 android:bottom="10dp" android:right="10dp"/>
                </shape>
</item>
</selector>
最后，需要在包含 button的xml文件里添加两项。例如main.xml 文件，需要在<Button />里加两项android：focusable="true" android:background="@drawable/button_color"

android background selector selector and usage instructions

Guess you like