Analysis of Example Code of Picture and Button Press State Change in Android

1. Set the background selector for pictures, so as to click or set whether it is selected or not, and switch the background

res/drawable/selector_settings_item_back.xml

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

Color value definition:

res/values/colors.xml

<?xml version="1.0" encoding="utf-8"?> 
<resources> 
  <color name="settingsItem">#ffffff</color> 
  <color name="settingsSelectedItem">#FFA500</color> 
</resources> 

2. Round corner button, press and lift to switch the background and switch the text color at the same time

res/layout/activity_xxx.xml

<Button 
  android:layout_width="wrap_content" 
  android:layout_height="wrap_content" 
  android:layout_weight="1" 
android:background="@drawable/selector_shape_corner_button" 
  android:text=" Under approval " android:textColor="@drawable/selector_font_style_corner_button" 
  android:textSize="13sp" 
  /> 

Which refers to two selector under res/drawable/,

One is to switch the background picture with clicking and lifting state, and the other is to switch the text color with clicking and lifting.

res/drawable/selector_shape_corner_button.xml

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

shape_corner_button.xml

<?xml version="1.0" encoding="utf-8"?> 
<shape xmlns:android="http://schemas.android.com/apk/res/android" 
  android:shape="rectangle"> 
  <corners 
    android:radius="5dp" /> 
  <solid 
    android:color="#001da1f2" /> 
  <stroke 
    android:width="1dp" 
    android:color="#1da1f2" /> 
</shape> 

shape_corner_button_fill.xml

<?xml version="1.0" encoding="utf-8"?> 
<shape 
xmlns:android="http://schemas.android.com/apk/res/android" 
  android:shape="rectangle"> 
  <corners 
    android:radius="5dp" /> 
  <solid 
    android:color="#ff1da1f2" /> 
  <stroke 
    android:width="1dp" 
    android:color="#1da1f2" /> 
</shape> 
<?xml version="1.0" encoding="utf-8"?> 
<selector xmlns:android="http://schemas.android.com/apk/res/android"> 
  <item android:state_focused="true" android:color="#ffffff"/> 
  <item android:state_pressed="true" android:color="#ffffff"/> 
  <item android:state_selected="true" android:color="#ffffff"/> 
  <item android:state_focused="false" android:color="#1da1f2"/> 
</selector > 

Summarize