日夜间模式切换

main.xml的布局

<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"    xmlns:tools="http://schemas.android.com/tools" android:id="@+id/activity_main"    android:layout_width="match_parent" android:layout_height="match_parent"    android:background="?attr/mainBackground"    tools:context="com.example.night.MainActivity"><!--注意:这里引用我们自定义的attr资源android:background="?attr/mainBackground"可以使用到此属性的控件带有日夜模式切换-->    <TextView        android:background="?attr/mainBackground"        android:id="@+id/bt_change"        android:layout_width="wrap_content" android:layout_height="wrap_content"        android:text="日夜模式切换"        android:layout_centerInParent="true"        /></RelativeLayout>

Main里面的代码

/*第一种设置夜间模式:通过重新给activity设置主题,然后销毁activity再创建activity,重新设置的主题才有效1.在values中的colors里设置颜色属性

<!--白天模式下的颜色--><color name="colorPrimary">#3F51B5</color><color name="colorPrimaryDark">#303F9F</color><color name="colorAccent">#FF4081</color><!--夜晚模式下的颜色--><color name="nightColorPrimary">#3b3b3b</color><color name="nightColorPrimaryDark">#383838</color><color name="nightColorAccent">#a72b55</color>
2.在style.xml中定义两组主题,也就是日间主题和夜间主题

 <!-- Base application theme.日间主题 -->    <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><!--夜间主题-->    <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>
3.创建attrs.xml文件

<!--自定义的属性方便引用--><attr name="mainBackground" format="color|reference"></attr>
4.需要夜间模式的布局引用attr自定义属性

5.java代码      a.判断存储的类型      b.点击事件,根据类型进行日夜的切换 */public class MainActivity extends AppCompatActivity implements View.OnClickListener {private TextView bt_change;    //默认是日间模式    private  int theme=R.style.AppTheme;    @Override    protected void onCreate(Bundle savedInstanceState) {        super.onCreate(savedInstanceState);        //判断是否有主题存储        if (savedInstanceState!=null){            theme = savedInstanceState.getInt("theme");            setTheme(theme);        }        setContentView(R.layout.activity_main);    //设计点击事件   bt_change=(TextView)findViewById(R.id.bt_change);        bt_change.setOnClickListener(this);    }    //根据点击事件,完成日间模式切换的代码.    @Override    public void onClick(View view) {        switch (view.getId()){            //点击,完成日间模式切换代码            case R.id.bt_change://切换日夜模式代码,三元运算符比if else效率更高                theme = (theme == R.style.AppTheme) ? R.style.NightAppTheme : R.style.AppTheme;               //重新创建                recreate();                break;            default:                break;        }    }//存theme属性

//这里需要特别注意这两个方法的区别  照片我已上传  一定要用第一个方法    @Override    protected void onSaveInstanceState(Bundle outState) {        super.onSaveInstanceState(outState);        outState.putInt("theme",theme);    }
    @Override    public void onSaveInstanceState(Bundle outState, PersistableBundle outPersistentState) {    super.onSaveInstanceState(outState, outPersistentState);    outState.putInt("theme",theme);    }
    //取theme属性    @Override    protected void onRestoreInstanceState(Bundle savedInstanceState) {        super.onRestoreInstanceState(savedInstanceState);        theme = savedInstanceState.getInt("theme");    }}

希望大家多多支持,评论!!!