启动活动只有一次 [英] Start activity only once

问题描述

我想我的应用程序启动一个活动仅在第一次应用程序启动。 任何一个有任何想法？

I want my app to start a activity only the first time the app launches. Any one got any idea?

我发现这一点，但只显示黑屏。

i found this but it only shows a black screen.

public class WhatsNew extends Activity {

public static final String PREFS_NAME = "MyPrefsFile";

protected void onCreate(Bundle state){

       super.onCreate(state);
       SharedPreferences settings = getSharedPreferences(PREFS_NAME, 0);
       boolean dialogShown = settings.getBoolean("dialogShown", false);

       if (!dialogShown) {
         // AlertDialog code here

         SharedPreferences.Editor editor = settings.edit();
         editor.putBoolean("dialogShown", true);
         editor.commit();    
       }
    }

}

推荐答案

我想请您谈一下，如日志页面上的活动，您将启动只有一次在应用程序的整个生活。 对于这一点，你可以使用共享preferences：

I think that you talk about activities like "log" page that you would launch only once in your application's whole life. For this, you can use sharedPreferences:

SharedPreferences prefs;
SharedPreferences.Editor editor;

和下方的startActivity（意向），添加：

and below your startActivity(intent), you add:

prefs = getSharedPreferences("nbRepet",Context.MODE_PRIVATE);
editor = prefs.edit();
editor.putInt("nbRepet", 1);
editor.commit();

现在你的变量nbRepet有1的值。

Now your variable nbRepet have 1 as value.

在这之后，你可以在上面你startActivity（意向）添加这些行，以验证您的活动一直没有推出之前：

After that, you can add these lines ABOVE your startActivity(intent) to verify that your activity was never launched before:

//在这里恢复nbRepet的价值。

//here you recover nbRepet's value..

preferences = MainActivity.this.getSharedPreferences("nbRepet", MODE_PRIVATE);      
int value = preferences.getInt("nbRepet", 0);

// ..你验证，如果你的活动之前推出。

//.. and you verify if your activity is launched before.

if(value<1)
{
    startActivity(intent);
}

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