android - Android recreate Fragment onBackPressed

Question

I have two activities and one fragment in my app. The first activity, MainActivity, is used to hold the fragment. It contains an ActionBarSherlock ActionBar and the fragment, WFrag. WFrag opens up the second activity, SettingsActivity, when you press a button. In SettingsActivity, you can choose settings that affect the behavior of WFrag. Naturally, I want the onBackPressed() method to go back to WFrag and update it with the user's new settings. My question is: how do you make it so that when you go back (via the back button) from SettingsActivity, you recreate (call onCreate() again) WFrag?

Answer 1

1. 覆盖 onBackPressed 或
2. 在 onStart/onResume 中添加更新

Answer 2

首先你必须重写 SettingActivity 的 onBackPressed()。

其次，当您开始第二个活动时，即 MainActivity 中的 SettingActivity，您必须以这种方式清除 Stack of previous activity

Intent intent = new Intent(this, SettingActivity.class);
intent.setFlags(Intent.FLAG_ACTIVITY_CLEAR_TOP); 
startActivity(intent);

onBackPressed() 方法中的 SettingActivity 也是如此，您必须以这种方式运行 MainActivity

Intent intent = new Intent(this, MainActivity.class);
intent.setFlags(Intent.FLAG_ACTIVITY_CLEAR_TOP); 
startActivity(intent);

或者，如果您从按钮单击重定向到 MainActivity，您可以使用上面的代码。