片段上的onstart()在android中被调用了两次 [英] onstart() on Fragment is getting called twice in android

问题描述

我有一个活动，其中有一个片段.在片段的onStart()中，我有所有网络调用.当app来自后台时，onStart()被调用两次，所有网络都被调用了两次，我还观察到onCreate()仅被调用了一次，有些人遇到了这样的问题.请帮帮我.我的片段交易代码如下

I have an activity on which I have one fragment. In onStart() of fragment I have all network calls.When app comes from background onStart() is getting called twice and all network are called twice and I also observed that onCreate()is called only once.Has some one faced such issue.Please help me out. My code for fragment transaction is as below

 MainFragment myFragment = new MainFragment ();
                FragmentManager fragmentManager = getSupportFragmentManager();
                FragmentTransaction fragmentTransaction = fragmentManager.beginTransaction();
                fragmentTransaction.replace(R.id.content_frame, myFragment, "MyFragment");
                fragmentTransaction.commitAllowingStateLoss();

提前感谢！！！

推荐答案

尝试在替换之前检查片段是否已添加

Try checking whether the fragment is already added before replacing

final FragmentManager fragmentManager = getSupportFragmentManager();
final Fragment content = fragmentManager.findFragmentById(R.id.content_frame);
if (content == null || !(content instanceof MainFragment)) {
    final FragmentTransaction fragmentTransaction = fragmentManager.beginTransaction();
    final MainFragment myFragment = new MainFragment();
    fragmentTransaction.replace(R.id.content_frame, myFragment, "MyFragment");
    fragmentTransaction.commitAllowingStateLoss();
}

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