Question

我试图在主要活动中设置我的片段文件中的文本。这是我的代码

这是我的mainActivity.java

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

    db = new SQLiteHandler(getApplicationContext());

    session = new SessionManager(getApplicationContext());

    if (!session.isLoggedIn()) {
        logoutUser();
    }

    HashMap<String, String> user = db.getUserDetails();

    fragmentTransaction = getSupportFragmentManager().beginTransaction();
    fragmentTransaction.add(R.id.main_container, new HomeFragment());
    fragmentTransaction.commit();

    getSupportActionBar().setTitle("Home Fragment");

    navigationView = (NavigationView)findViewById(R.id.navigation_view);
    navigationView.setNavigationItemSelectedListener(new NavigationView.OnNavigationItemSelectedListener() {
        @Override
        public boolean onNavigationItemSelected(MenuItem item) {
            switch (item.getItemId()){
                case R.id.home_id:
                    fragmentTransaction = getSupportFragmentManager().beginTransaction();
                    fragmentTransaction.replace(R.id.main_container, new HomeFragment());
                    fragmentTransaction.commit();
                    getSupportActionBar().setTitle("Home Fragment");
                    item.setChecked(true);
                    break;

                case R.id.help_id:
                    fragmentTransaction = getSupportFragmentManager().beginTransaction();
                    fragmentTransaction.replace(R.id.main_container, new HelpFragment());
                    fragmentTransaction.commit();
                    getSupportActionBar().setTitle("Help Fragment");
                    item.setChecked(true);
                    break;

                case R.id.logout:
                    logoutUser();
            }

            return false;
        }
    });

}

我有这个（HomeFragment.java）

public class HomeFragment extends Fragment {

 public HomeFragment() {
    // Required empty public constructor
 }

 @Override
 public View onCreateView(LayoutInflater inflater, ViewGroup container,
                         Bundle savedInstanceState) {
    return inflater.inflate(R.layout.fragment_home, container, false);
 }
}

我在我的fragment_home.xml

上有这个

<TextView
        android:id="@+id/name"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:padding="10dp"
        android:textColor="@color/lbl_name"
        android:textSize="24dp" />

我也可以设置＆＃39; name＆＃39;来自mainActivity？如果有，请告诉我怎么做？

Answer 1

添加片段时，您可以为其指定标记：

fragmentTransaction.add(R.id.main_container, new HomeFragment(), "MY_FRAGMENT");
fragmentTransaction.commit();

当您需要更改TextView时，可以使用used标签恢复片段，并调用更改文本的片段方法：

HomeFragment fragment = (HomeFragment) getSupportFragmentManager()
    .findFragmentByTag("MY_FRAGMENT");
fragment.changeText("New text");

如果您没有使用支持库，请将getSupportFragmentManager()替换为getFragmentManager()。

HomeFragment类中的方法是：

public void changeText(String newText) {
    TextView textview = (TextView) getView().findViewById(R.id.name);
    textview.setText(newText);
}

Answer 2

这是您的错误，您没有为textview ing创建视图提供任何视图，请尝试此

HomeFragment Class

public static TextView mTextView;



   @Override
     public View onCreateView(LayoutInflater inflater, ViewGroup container,
                             Bundle savedInstanceState) {
      View  view = inflater.inflate(R.layout.fragment_home, container, false);

     mTextView=(TextView)view.findviewById(R.id.name);

    return view;
    }

在你的班级活动中

添加片段调用之后

HomeFragment.mTextView.setText("Name");

试试上面的代码

从主要活动设置文本片段

2 个答案: