日夜间模式的切换

在values里的colors.xml里

<?xml version="1.0" encoding="utf-8"?><resources>    <!--日间模式下的颜色-->    <color name="colorPrimary">#3F51B5</color>    <color name="colorPrimaryDark">#303F9F</color>    <color name="colorAccent">#FF4081</color>    <!--夜间模式下的颜色-->    <color name="nightColorPrimary">#3b3b3b</color>    <color name="nightColorPrimaryDark">#383838</color>    <color name="nightColorAccent">#a72b55</color></resources>

然后在values里的styles.xml里

<resources>    <!-- 日间模式 -->    <style name="AppTheme" parent="Theme.AppCompat.Light.DarkActionBar">        <!-- Customize your theme here. -->        <item name="colorPrimary">@color/colorPrimary</item>        <item name="colorPrimaryDark">@color/colorPrimaryDark</item>        <item name="colorAccent">@color/colorAccent</item>        <item name="android:textColor">@android:color/black</item>        <item name="mainBackground">@android:color/white</item>    </style>    <!-- 夜间模式 -->    <style name="NightAppTheme" parent="Theme.AppCompat.Light.DarkActionBar">        <!-- Customize your theme here. -->        <item name="colorPrimary">@color/nightColorPrimary</item>        <item name="colorPrimaryDark">@color/nightColorPrimaryDark</item>        <item name="colorAccent">@color/nightColorAccent</item>        <item name="android:textColor">@android:color/white</item>        <item name="mainBackground">@color/nightColorPrimaryDark</item>    </style></resources>

然后在values里创建attrs.xml

<?xml version="1.0" encoding="utf-8"?><resources>    <!--reference 引用-->    <attr name="mainBackground" format="color|reference"></attr></resources>

在相对布局中或者线性布局中添加:

android:background="?attr/mainBackground"

MainActivity里

//方法1
package bawei.com.riye;import android.content.SharedPreferences;import android.support.v7.app.AppCompatActivity;import android.os.Bundle;import android.view.View;import android.widget.Button;public class MainActivity extends AppCompatActivity {    private SharedPreferences sharedPreferences;    private SharedPreferences.Editor edit;    private Button button;    //默认的日间模式    private int theme = R.style.AppTheme;    @Override    protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
  //恢复数据 做判空        
if (savedInstanceState != null) {           
theme = savedInstanceState.getInt("theme");            
//设置主题 此方法必须在setContentView()之前调用          
  setTheme(theme);        }//         
setContentView(R.layout.activity_main);       
 button = (Button) findViewById(R.id.riye);       
 button.setOnClickListener(new View.OnClickListener() {      
 @Override 
public void onClick(View v) {        
    //切换日夜间模式               
 theme = (theme == R.style.AppTheme) ? R.style.NightAppTheme : R.style.AppTheme;
//重新创建               
 recreate();                           
 }        });    }   
 //保存数据   
 @Override    
protected void onSaveInstanceState(Bundle outState) {        
super.onSaveInstanceState(outState);        
outState.putInt("theme", theme);    }    
//恢复数据    
@Override   
 protected void onRestoreInstanceState(Bundle savedInstanceState) {        super.onRestoreInstanceState(savedInstanceState);       
 theme = savedInstanceState.getInt("theme");    }}


//方法2
package bawei.com.riye;import android.content.SharedPreferences;import android.support.v7.app.AppCompatActivity;import android.os.Bundle;import android.view.View;import android.widget.Button;public class MainActivity extends AppCompatActivity {    private SharedPreferences sharedPreferences;    private SharedPreferences.Editor edit;    private Button button;    @Override    protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);  
    sharedPreferences = getSharedPreferences("jiangjun",MODE_PRIVATE);      
 edit = sharedPreferences.edit();
 boolean riye = sharedPreferences.getBoolean("riye", false);
       if (riye){        
 setTheme(R.style.NightAppTheme);      
 }else {           
setTheme(R.style.AppTheme);//       
 }      
  setContentView(R.layout.activity_main);      
  button = (Button) findViewById(R.id.riye);       
 button.setOnClickListener(new View.OnClickListener() {         
   @Override         
   public void onClick(View v) {               
 boolean riye1 = sharedPreferences.getBoolean("riye", false);//             
   if (riye1){//               
         edit.putBoolean("riye",false);//     
               edit.commit();//      
         }else {//         
               edit.putBoolean("riye",true);//       
               edit.commit();//               
 }    //重新创建            
    recreate();                          
  }        });    }