如何在不承载该片段的活动中刷新从 Listview 接收数据的片段中的 Textview

我创建了一个包含 5 个片段的底部导航栏，因此一旦单击每个选项卡，它将从一个片段切换到另一个片段。

问题是：第二个片段（搜索片段）有 1 个带有 setOnClickListener 的 TextView，因此一旦它被舔，一个布局活动将在顶部打开，其中包括一个 ListView 以允许用户选择/单击特定项目，以便稍后此选定项目信息应显示在（搜索片段）内的该 TextView 上。

问题是这个 Textview 不会更新，除非我调用 mainActivity 来更新底部导航栏中的所有片段

我的问题是如何在不调用 MainActivity 的情况下刷新该特定片段。

 public class MainActivity extends AppCompatActivity {



final Fragment f1 = new HomeFragment();
final Fragment f2 = new SearchFragment();
final Fragment f3 = new CameraFragment();
final Fragment f4 = new ChatFragment();
final Fragment f6 = new LogginFragment();

final FragmentManager fm = getSupportFragmentManager();
Fragment active = f1;

@Override
 protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main);



    BottomNavigationViewEx bnve = (BottomNavigationViewEx) findViewById(R.id.bottom_navigation);

    bnve.enableAnimation(false);
    bnve.enableShiftingMode(false);
    bnve.enableItemShiftingMode(false);
    bnve.setOnNavigationItemSelectedListener(navListener);

    if(SharePrefManager.getInstance(this).isLoggedin()){
        finish();
        startActivity(new Intent(this, SuccessActivity.class));
        return;
    }
    fm.beginTransaction().add(R.id.fragment_container, f6, "6").hide(f6).commit();
    //fm.beginTransaction().add(R.id.fragment_container, f5, "5").hide(f5).commit();
    fm.beginTransaction().add(R.id.fragment_container, f4, "4").hide(f4).commit();
    fm.beginTransaction().add(R.id.fragment_container, f3, "3").hide(f3).commit();
    fm.beginTransaction().add(R.id.fragment_container, f2, "2").hide(f2).commit();
    fm.beginTransaction().add(R.id.fragment_container, f1, "1").commit();



}



public BottomNavigationViewEx.OnNavigationItemSelectedListener navListener =
        new BottomNavigationViewEx.OnNavigationItemSelectedListener() {
            @Override
            public boolean onNavigationItemSelected(@NonNull MenuItem item) {
                switch (item.getItemId()) {

                    case R.id.nav_home:
                        fm.beginTransaction().hide(active).show(f1).commit();
                        active = f1;
                        return true;

                    case R.id.nav_search:
                        fm.beginTransaction().hide(active).show(f2).commit();
                        active = f2;
                        return true;
                    case R.id.nav_camera:
                        fm.beginTransaction().hide(active).show(f3).commit();
                        active = f3;
                        return true;
                    case R.id.nav_chat:
                        fm.beginTransaction().hide(active).show(f4).commit();
                        active = f4;
                        return true;
                    case R.id.nav_account:
                        fm.beginTransaction().hide(active).show(f6).commit();
                        active = f6;
                        return true;

                }



                return false;

            }
        };

    }

------------------------SearchFragment 类------------------------ ----------

这是搜索片段，其中包含应该在不调用 MainActivity 的情况下更新/引用的 textView（类别）

public class SearchFragment extends Fragment  {


 private Context mContext;
 TextView Categories;


static boolean status = false;
String SelectedItem;

@Nullable
@Override
public View onCreateView(LayoutInflater inflater, @Nullable ViewGroup container, @Nullable Bundle savedInstanceState) {

    View v = inflater.inflate(R.layout.fragment_search,container,false);
    Categories = (TextView) v.findViewById(R.id.categories);
    SelectedItem = DataHolder.getInstance().getItem();





        Categories.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                startActivity(new Intent(mContext, AllCateActivity.class));

            }
        });

        if(status){Categories.setText(SelectedItem);}


    return v;
}

public void ChangeStatus(Boolean status){

    this.status = status;
    }

@Override
  public void onAttach(Context context) {
    super.onAttach(context);
    mContext=context;
     }




 }

--------------------------DataHolder 类-------------- -----------

这作为一种设计模式在搜索片段和 Categories_Activity 之间共享参数

  public class DataHolder {

 private static DataHolder dataHolder = null;

 private DataHolder() {
     }

  public static DataHolder getInstance() {
if (dataHolder == null)
{
    dataHolder = new DataHolder();
}
return dataHolder;
 }


  private  String item;

 public String getItem() {
return item;
 }

public void setItem(String item) {
 this.item = item;
     }

 }

--------------------------Categories_Activity------------------------ ----------

此活动一旦被称为列表视图，将显示允许用户选择一个项目。因此，一旦选择了一个项目，它将启动 MainActivity 以刷新搜索片段中的文本字段

 public class Categories_Activity extends AppCompatActivity implements View.OnClickListener {

ImageView BacktoMainCate;
ListView subCate;
public String selectedItem;


@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.tab_subcategory);
    subCate = (ListView)findViewById(R.id.listview_subcate);
    BacktoMainCate = (ImageView)findViewById(R.id.BacktoMainCate);
    BacktoMainCate.setOnClickListener(this);

           final SearchFragment SF = new SearchFragment();
    subCate.setOnItemClickListener(new AdapterView.OnItemClickListener() {
        @Override
        public void onItemClick(AdapterView<?> parent, View view, int position, long id) {
             selectedItem = String.valueOf(parent.getItemAtPosition(position));
            DataHolder.getInstance().setItem(selectedItem);
            SF.ChangeStatus(true);

  Intent in = new Intent(Categories_Activity.this,SuccessActivity.class);
                startActivity(in);

    });

}





@Override
public void onClick(View v) {

    if (v == BacktoMainCate){
        //startActivity(new Intent(this,AllCateActivity.class));
        finish();
    }




   }
}