如何知道Activity在Android中何时完成？

Question

In my android app I want to change the input method. So I start a new Activity which shows the language settings in the device. Then user can change it. However then I want to know that if the user has changed it. So I wrote a function for that also. My code so far is...

Intent enableIME = new Intent(android.provider.Settings.ACTION_INPUT_METHOD_SETTINGS);
                    startActivityForResult(enableIME,0);


                    if(isInputMethodEnabled()){
                        activateshadow.setBackgroundDrawable(getResources().getDrawable(R.drawable.button_pressed));
                        activateshadow.setText("Deactivate Shadow");
                        prefs.edit().putBoolean("Activate", false).commit();
                    }else{
                        Toast.makeText(MainActivity.this,"You haven't change the input method to simpleIME.In order to activate you must change it.",Toast.LENGTH_SHORT).show();
                    }

my is inputMethodEnabled function is....

  public boolean isInputMethodEnabled() {
  boolean isIME ;  
  String id = Settings.Secure.getString(getApplicationContext().getContentResolver(), Settings.Secure.DEFAULT_INPUT_METHOD);
    String [] name = id.split("/.");
   // Toast.makeText(MainActivity.this,"s:"+name[1]+":s",Toast.LENGTH_SHORT).show();
    if(name[1].contains("SimpleIME") ){
        isIME = true ;
    }else{
        isIME = false;
    }
   //  Toast.makeText(MainActivity.this,"Returning..."+isIME,Toast.LENGTH_SHORT).show();
    return isIME;
}

if(isInputMethodEnabled()) always fails because when the new intent(settings) opens and it take some time to change the input method to simpleIME . How to fix this problem?

Answer 1

You catch when a launched Activity returns in onActivityResult . The requestCode you supplied to startActivityForResult will be a parameter, as will the Activity 's result. The Activity may also set other data which you didn't ask about.

public void onActivityResult(int requestCode, int resultCode, Intent data) {
    if (requestCode == 555) {//555 is the intent ID you gave in startActivityForResult(enableIME,555);
        if (resultCode == /*Result1*/)
            //Do something
        else {
            //Do something else
        }
    }
}

You need a unique id when calling startActivityForResult(enableIME,0);

startActivityForResult(enableIME, 555);

Better still replace 555 with a named variable.

Answer 2

if u look at android life cycle, when activity is finished whole android call onDestroy() method. so u can call and override this method. just need write:

@override
protected void onDestroy(){
// code
super.onDestroy();
}

u can manage and override all of life cycle's parts in android eg: onResume to get current activity

i hope this help u