從後臺打開android應用程序

Question

每當我的android應用程序進入後臺時，我總是希望在每次應用程序來自後臺時打開我的密碼活動，如何在我的代碼中實現此功能？

Answer 1

請按照下列步驟操作：

1. 添加新類全局

   public class Global extends Application 
   { 
   
   private static Global mInstance; 
   
   @Override 
   public void onCreate() { 
       super.onCreate(); 
   
       mInstance = this; 
   
       ApplicationLifeCycleHandler handler = new ApplicationLifeCycleHandler(); 
       registerActivityLifecycleCallbacks(handler); 
       registerComponentCallbacks(handler); 
   } 
   
   
   public static Global getInstance(){ 
       return mInstance; 
   } 
   } 
   

2. 在您的清單中的應用程序標記添加此行像

   <application 
        android:name=".Global" 
       </application> 
   

3. 添加這個類和打開你的密碼意圖當應用程序來到背景前景如

   public class ApplicationLifeCycleHandler implements Application.ActivityLifecycleCallbacks, ComponentCallbacks2 { 
   
   public static Activity activity; 
   
   private static final String TAG = ApplicationLifeCycleHandler.class.getSimpleName(); 
   public static boolean isInBackground = true; 
   
   @Override 
   public void onActivityCreated(Activity activity, Bundle bundle) { 
   } 
   
   @Override 
   public void onActivityStarted(Activity activity) { 
       this.activity = activity; 
   } 
   
   @Override 
   public void onActivityResumed(Activity activity) { 
       this.activity = activity; 
   
       if (isInBackground) { 
   
        Intent intent = new Intent(activity, PasswordActivity.class);//set your password activity 
        activity.startActivity(intent); 
   
        Log.d(TAG, "app went to foreground"); 
        isInBackground = false; 
       } 
   } 
   
   @Override 
   public void onActivityPaused(Activity activity) { 
   } 
   
   @Override 
   public void onActivityStopped(Activity activity) { 
   } 
   
   @Override 
   public void onActivitySaveInstanceState(Activity activity, Bundle bundle) { 
   } 
   
   @Override 
   public void onActivityDestroyed(Activity activity) { 
   } 
   
   @Override 
   public void onConfigurationChanged(Configuration configuration) { 
   } 
   
   @Override 
   public void onLowMemory() { 
   } 
   
   @Override 
   public void onTrimMemory(int i) { 
       if (i == ComponentCallbacks2.TRIM_MEMORY_UI_HIDDEN) { 
        Log.d(TAG, "app went to background"); 
        isInBackground = true; 
   
       } 
   } 
   } 
   

希望它會幫助你，請讓我知道，如果你正面臨的任何問題。謝謝