定制知识积累

若对系统自带的widget外观不满意,可以进行定制,原理是修改widget属性对应的drawable,操作步骤如下:

1.在android系统的styles.xml/theme.xml中找到控件的属性所对应的drawable(图片或selector);

2.在项目的styles.xml中自定义风格,继承系统风格,修改相应的drawable;

3.在layout.xml中设置widget的style = "@style/自定义style";

CheckBox定制

1. 在sdk/platforms/android-**/data/res文件夹内搜索"styles.xml",并打开;
2. 找到所需控件的style:
   

    <style name="Widget.CompoundButton.CheckBox">
        <item name="android:button">?android:attr/listChoiceIndicatorMultiple</item>
    </style>

   属性开头是"?",表明引用了系统的theme属性;
3. 继续在当前目录内搜索"theme.xml",打开后找到"listChoiceIndicatorMultiple":
   

   <item name="listChoiceIndicatorMultiple">@android:drawable/btn_check</item>

4. 再次搜索"btn_check",可以找到"btn_check.xml":

   <selector xmlns:android="http://schemas.android.com/apk/res/android">
   
       <!-- Enabled states -->
           
       <item android:state_checked="true" android:state_window_focused="false"
             android:state_enabled="true"
             android:drawable="@drawable/btn_check_on" />
       <item android:state_checked="false" android:state_window_focused="false"
             android:state_enabled="true"
             android:drawable="@drawable/btn_check_off" />
   
       <item android:state_checked="true" android:state_pressed="true"
             android:state_enabled="true"
             android:drawable="@drawable/btn_check_on_pressed" />
       <item android:state_checked="false" android:state_pressed="true"
             android:state_enabled="true"
             android:drawable="@drawable/btn_check_off_pressed" />
   
       <item android:state_checked="true" android:state_focused="true"
             android:state_enabled="true"
             android:drawable="@drawable/btn_check_on_selected" />
       <item android:state_checked="false" android:state_focused="true"
             android:state_enabled="true"
             android:drawable="@drawable/btn_check_off_selected" />
   
       <item android:state_checked="false"
             android:state_enabled="true"
             android:drawable="@drawable/btn_check_off" />
       <item android:state_checked="true"
             android:state_enabled="true"
             android:drawable="@drawable/btn_check_on" />
   
   
       <!-- Disabled states -->
   
       <item android:state_checked="true" android:state_window_focused="false"
             android:drawable="@drawable/btn_check_on_disable" />
       <item android:state_checked="false" android:state_window_focused="false"
             android:drawable="@drawable/btn_check_off_disable" />
   
       <item android:state_checked="true" android:state_focused="true"
             android:drawable="@drawable/btn_check_on_disable_focused" />
       <item android:state_checked="false" android:state_focused="true"
             android:drawable="@drawable/btn_check_off_disable_focused" />
   
       <item android:state_checked="false" android:drawable="@drawable/btn_check_off_disable" />
       <item android:state_checked="true" android:drawable="@drawable/btn_check_on_disable" />
   
   </selector>

   可知系统定义了该widget选中/未选中时的图片,因此定制时,通过创建style,继承系统的checkbox风格,引用自定义selector即可;
5. 在项目drawable目录下创建"selector_my_checkbox.xml":
   

   <?xml version="1.0" encoding="utf-8"?>
   <selector xmlns:android="http://schemas.android.com/apk/res/android">
       <item android:state_checked="true" android:drawable="@drawable/my_checkbox_selected" ></item>
       <item android:drawable="@drawable/my_checkbox_unselected"></item>
   </selector>

6. 在项目values/styles.xml中自定义style:
   

    <style name="MyCheckBox" parent="@android:style/Widget.CompoundButton.CheckBox">
        <item name="android:button">@drawable/selector_my_checkbox</item>
    </style>

7. 设置CheckBox的属性即可:
   

    <CheckBox
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        style="@style/MyCheckBox"/>