如何确保在用户退出时调用onDestroy方法

Question

我无法在代码中调用onDestroy（）方法。 我的代码的目的是当用户通过使用屏幕底部的按钮退出应用程序时编写两个txt文件。这可以节省他们的进展。 然后将它加载到OnCreate（）方法 然而，OnDestroy（）方法不会被调用 有没有办法在手机上按下退出按钮时发生这种情况？ 代码的主体不包括在内，因为它对我的问题并不重要。谢谢。 这里是我的代码

protected void onCreate(Bundle savedInstanceState) { 
    super.onCreate(savedInstanceState); 
    setContentView(R.layout.activity_card_question); 
    try{ 
     FileInputStream fis = openFileInput("correct.txt"); 
     //InputStreamReader isr = new InputStreamReader(fIn); 
     StringBuffer sb= new StringBuffer(); 
     BufferedReader br= new BufferedReader(new InputStreamReader(fis)); 
     String strLine = null; 
     int x=0; 


     while((strLine=br.readLine())!=null){ 
      arrayCorrect[x]=strLine; 
      x++; 

     } 


     //Log.i("File Reading stuff", "success = " + "hell"); 

    } catch (IOException ioe) 
    {//ioe.printStackTrace(); 
    } 
    try{ 
     FileInputStream fis = openFileInput("incorrect.txt"); 
     //InputStreamReader isr = new InputStreamReader(fIn); 
     StringBuffer sb= new StringBuffer(); 
     BufferedReader br= new BufferedReader(new InputStreamReader(fis)); 
     String strLine = null; 
     int x=0; 


     while((strLine=br.readLine())!=null){ 
      arrayIncorrect[x]=strLine; 
      x++; 

     } 


     //Log.i("File Reading stuff", "success = " + "hell"); 

    } catch (IOException ioe) 
    {//ioe.printStackTrace(); 
    } 
@Override 
public void onDestroy() { 
    super.onDestroy(); // Always call the superclass 
    try{ 
     FileOutputStream fOut = openFileOutput("correct.txt", 
       MODE_WORLD_READABLE); 
     OutputStreamWriter osw = new OutputStreamWriter(fOut); 

     // Write the string to the file 
     for(int x=0; x<arrayCorrect.length; x++) { 
      osw.write(arrayCorrect[x] + "\n"); 
     } 

    /* ensure that everything is 
    * really written out and close */ 
     osw.flush(); 
     osw.close(); 
    } 
    catch(IOException ioe){ 
     ioe.printStackTrace(); 
    } 
    try{ 
     FileOutputStream fOut = openFileOutput("incorrect.txt", 
       MODE_WORLD_READABLE); 
     OutputStreamWriter osw = new OutputStreamWriter(fOut); 

     // Write the string to the file 
     for(int x=0; x<arrayIncorrect.length; x++) { 
      osw.write(arrayIncorrect[x] + "\n"); 
     } 

    /* ensure that everything is 
    * really written out and close */ 
     osw.flush(); 
     osw.close(); 
    } 
    catch(IOException ioe){ 
     ioe.printStackTrace(); 
    } 

    // startActivity(new Intent(getApplication(),second.class)); 
} 

Answer 1

你不应该把这段代码放在onDestroy方法中。您应该在onPause方法上启动后台服务。