Android 调用Fragment.getChildFragmentManager()时出现NullPointerException
我正在尝试在“活动”工具栏上实现SearchView。在这里,我需要从MainActivity的选项卡片段下搜索产品。当单击搜索图标时,应用程序崩溃,我得到如下错误Android 调用Fragment.getChildFragmentManager()时出现NullPointerException,android,tabs,searchview,Android,Tabs,Searchview,我正在尝试在“活动”工具栏上实现SearchView。在这里,我需要从MainActivity的选项卡片段下搜索产品。当单击搜索图标时,应用程序崩溃,我得到如下错误 java.lang.NullPointerException: Attempt to invoke virtual method 'android.support.v4.app.FragmentManager android.support.v4.app.Fragment.getChildFragmentManager()'
java.lang.NullPointerException: Attempt to invoke virtual method 'android.support.v4.app.FragmentManager android.support.v4.app.Fragment.getChildFragmentManager()' on a null object reference
这是什么意思?我做了什么来修复这个错误?请帮帮我
更新:
public Fragment getCurrentFragment() {
mFragmentManager = getSupportFragmentManager();
mFragmentTransaction = mFragmentManager.beginTransaction();
Fragment fragment = mFragmentManager.findFragmentById(R.id.container);
List<Fragment> fragmentList = fragment.getChildFragmentManager().getFragments(); // Got error in this line
for (Fragment myFragment : fragmentList) {
if (myFragment.getUserVisibleHint()) {
return myFragment;
}
}
return fragmentList.get(0);
}
公共片段getCurrentFragment(){
MFFragmentManager=getSupportFragmentManager();
MFFragmentTransaction=MFFragmentManager.beginTransaction();
Fragment Fragment=mffragmentmanager.findffragmentbyid(R.id.container);
List fragmentList=fragment.getChildFragmentManager().getFragments();//此行出错
for(片段myFragment:fragmentList){
if(myFragment.getUserVisibleHint()){
返回myFragment;
}
}
返回碎片列表。获取(0);
}
错误很明显。您正在对null
的对象调用getChildFragmentManager
在您的情况下,这意味着fragmentmanager无法找到ID为:R.ID.container
Fragment fragment = mFragmentManager.findFragmentById(R.id.container);
List<Fragment> fragmentList = fragment.getChildFragmentManager().getFragments();
Fragment Fragment=mffragmentmanager.findffragmentbyid(R.id.container);
List fragmentList=fragment.getChildFragmentManager().getFragments();
请发布产生此错误的代码?错误信息非常清楚。调用getChildFragmentManager的对象为空。发布一些你如何使用它的代码。请检查我编辑的代码@rvdk请检查我编辑的代码@PrerakSola@ParamaSudha请只张贴相关代码