Android 如何在运行时将主题设置为活动？在 onCreate 和 setContentView 之前调用 setTheme 不起作用

How to setTheme to an activity at runtime? It doesn't work call setTheme before onCreate and setContentView

提问by herman brain

I want setThemeto an activity at runtime, I have search some solutions by google. someone said call setThemebefore onCreate and setContentView can works, the code section like

我想setTheme在运行时进行活动，我通过谷歌搜索了一些解决方案。有人说setTheme在 onCreate 和 setContentView 之前调用可以工作，代码部分像

public void onCreate(Bundle savedInstanceState) {
    setTheme(android.R.style.Theme_Translucent_NoTitleBar);
    super.onCreate(savedInstanceState);
    ...
    setContentView(...)
}

but it not works, I want to know, is there another solution can setTheme to activity?

但它不起作用，我想知道，是否有另一种解决方案可以将主题设置为活动？

回答by Praveenkumar

Just try this - set your theme after super.onCreate(savedInstanceState);and before setContentView(...)

试试这个 - 在super.onCreate(savedInstanceState);前后设置你的主题setContentView(...)

Like below code -

像下面的代码 -

public void onCreate(Bundle savedInstanceState) 
{
    super.onCreate(savedInstanceState);
    setTheme(android.R.style.Theme_Translucent_NoTitleBar); // Set here
    setContentView(...)
}

回答by Chris.Jenkins

Actually this only worked for me if I set it before calling super.onCreate(savedInstanceState);

实际上，如果我在打电话之前设置它，这只对我有用 super.onCreate(savedInstanceState);

public void onCreate(Bundle savedInstanceState)
{
    final int themeRes = getIntent().getIntExtra(EXTRA_THEME_ID, 0);
    if (themeRes != 0) setTheme(themeRes);
    super.onCreate(savedInstanceState);
    //ect...
}

回答by Umesh

setContentView(...);
setTheme(R.style.MyTheme);
setContentView(...);

It must work well..

它必须运作良好..

More on Themes, Read this http://entertheinfinity.blogspot.in/2016/06/designing-android-interface-themes.html

有关主题的更多信息，请阅读 http://entertheinfinity.blogspot.in/2016/06/designing-android-interface-themes.html

回答by Eric

To set the theme at runtime and fix the "black background" problem:

在运行时设置主题并修复“黑色背景”问题：

1. the theme should be set before onCreate().

   public void onCreate(Bundle savedInstanceState) {
       setTheme(android.R.style.Theme_Translucent_NoTitleBar);
       super.onCreate(savedInstanceState);
       ...
       setContentView(...)
   }
   

2. the theme of the transparent activity in the android manifest should be set to any theme that has a transparent background (e.g. a dialog theme).

   • this tells the Android OS continue to draw the activities behind the transparent activity so that you don't end up with a black background.

   • i'm using an AppCompatActivity; i need to use an AppCompattheme:

     <?xml version="1.0" encoding="utf-8"?>
     <manifest
         xmlns:android="http://schemas.android.com/apk/res/android"
         package="com.example.app">
         ...
         <application
             ...>
             ...
             <activity
                 android:name=".TranslucentActivity"
                 android:theme="@style/Theme.AppCompat.DayNight.Dialog"
                 .../>
             ...
         </application>
     </manifest>
     

1. 主题应该是之前设定的onCreate()。

   public void onCreate(Bundle savedInstanceState) {
       setTheme(android.R.style.Theme_Translucent_NoTitleBar);
       super.onCreate(savedInstanceState);
       ...
       setContentView(...)
   }
   

2. android manifest 中透明活动的主题应该设置为任何具有透明背景的主题（例如对话框主题）。

   • 这告诉 Android 操作系统继续在透明活动后面绘制活动，这样您就不会以黑色背景结束。

   • 我正在使用AppCompatActivity; 我需要使用一个AppCompat主题：

     <?xml version="1.0" encoding="utf-8"?>
     <manifest
         xmlns:android="http://schemas.android.com/apk/res/android"
         package="com.example.app">
         ...
         <application
             ...>
             ...
             <activity
                 android:name=".TranslucentActivity"
                 android:theme="@style/Theme.AppCompat.DayNight.Dialog"
                 .../>
             ...
         </application>
     </manifest>