为什么在重新启动应用程序时在onActivityResult上获取NullPointerException？

Question

I have a problem on onActivityResult method of an activity(Cordova activity), following is the case where this happens

1. Launch a Activity1
2. StartActivityForResult named Activity2
3. Press home button
4. Relaunch the app through clicking on app icon

am getting the splash activity called and then activity1 is called but this gives me nullpointerException on onActivityResult and the activity is not displaying the view as well.

Can anyone give me the solution to avoid this error?

<activity
        android:name=".MDLIVEMain"
        android:configChanges="orientation|keyboardHidden|keyboard|screenSize|locale"
        android:label="@string/app_name"
        android:launchMode="singleTask"
        android:taskAffinity=""
        android:clearTaskOnLaunch="true"
        android:finishOnTaskLaunch="true"
        android:excludeFromRecents="true"
        android:screenOrientation="portrait"
        android:theme="@android:style/Theme.Black.NoTitleBar"
        android:windowSoftInputMode="adjustResize" />

Starting activity for result part

 Intent passcodeIntent = new Intent(getActivity(), PasscodeActivity.class);
 passcodeIntent.putExtra("passcode_data_page",passcodeDataPage);
 startActivityForResult(passcodeIntent, PASSCODE_RESULT_PAGE);

OnaActivityResult code

     @Override
    protected void onActivityResult(int requestCode, int responseCode, Intent intent) {
        CordovaPlugin callback = this.activityResultCallbacks;
        try {
            Log.d("onActivityResult",requestCode+"-"+responseCode+"");
            if (requestCode == REQUEST_CODE_RESOLVE_ERR && responseCode == RESULT_OK) {
                mConnectionResult = null;
                mPlusClient.connect();
            }

            if (callback != null) {
                callback.onActivityResult(requestCode, responseCode, intent);
            }
            getActivity().runOnUiThread(new Runnable() {
                public void run() {
                    mConnectionProgressDialog.dismiss();
                }
            });

            if (requestCode == PASSCODE_RESULT_PAGE) {
                if (responseCode == RESULT_OK) {
                    activityVisible = true;
                    this.callbackContext.success(intent.getExtras().getString("passcode_pin"));
                } else {
                    this.callbackContext.success(intent.getExtras().getString("passcode_pin"));
                    isFromPasscodePage = true;
                }
            }
        }catch (Exception e){
            e.printStackTrace();
//            finish();
        }
    }

Error come here

this.callbackContext.success(intent.getExtras().getString("passcode_pin"));
                isFromPasscodePage = true;

Answer 1

onActivityResult() android:launchMode="singleTask"与android:launchMode="singleTask" ，请尝试删除此属性。

Answer 2

Dismissing a (progress) dialog in onActivityResult is questionable. onActivityResult is called after some other activity was active. In any case calling it from a runnable is unnecessary.

You are calling intent.getExtras().getString. There is no guarantee that the intent has extras or a string "passcode_pin" especially if the passcode activity was cancelled.