Question

嗨，我是一名学生，正在尝试构建一个应用程序。我想通过在导航抽屉上点击进入主要活动来加载片段。我能够将导航抽屉附加到家庭活动中。但是使用以下代码，我无法在活动中加载片段。 “ loadDashboard”功能工作正常，但“ onNavigationItemSelected”方法无效。请帮助...代码在下面...

public class HomeActivity extends AppCompatActivity {

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

    NavigationView nv = findViewById(R.id.navigation_view);
    nv.setNavigationItemSelectedListener(new NavigationView.OnNavigationItemSelectedListener() {
        @Override
        public boolean onNavigationItemSelected(@NonNull MenuItem item) {
            switch (item.getItemId()) {
                case R.id.menuitemdashboard:
                    getSupportFragmentManager().beginTransaction().replace(R.id.viewContainer, new dashboard()).commit();
                    break;
                case R.id.menuitemlogout:
                    break;
                case R.id.menuitemprofile:
                    break;
                case R.id.menuitemreports:
                    break;
                case R.id.menuitemvisits:
                    getSupportFragmentManager().beginTransaction().replace(R.id.viewContainer, new visits()).commit();
                    break;
            }
            return true;
        }
    });

}

private void loadDashboad() {
    FragmentManager fm = getSupportFragmentManager();
    FragmentTransaction ft = fm.beginTransaction();
    dashboard dash = new dashboard();
    ft.add(R.id.viewContainer, dash);
    ft.commit();
}

}

Answer 1

您的代码很好，您所缺少的是为导航菜单项提供功能。将以下行替换为要添加的片段

child: Row(children: <Widget>[
        Column(children: <Widget>[
            Padding(
              padding: EdgeInsets.all(5.0),
              child: Container(
                decoration: new BoxDecoration(
                  border: new Border(right: BorderSide(color: Colors.black))
                ),
                child: Column(
                        children: <Widget>[
                          Text('Points'),
                          Text('38'),
                        ],
                      ),
              ),
            ),

        ],),
        // green bar
        Column(children: <Widget>[
          Padding(
            padding: EdgeInsets.only(right:10.0),
            child: Container(
              width:ratewidth,
              decoration: new BoxDecoration(
                    border: new Border(bottom: BorderSide(color: Colors.green, width: 5.0))
                  ),
            ),
          )

        ],),
        //yellow bar
        Column(children: <Widget>[
          Padding(
            padding: EdgeInsets.only(right:10.0),
            child: Container(
              width:ratewidth,
              decoration: new BoxDecoration(
                    border: new Border(bottom: BorderSide(color: Colors.yellow, width: 5.0))
                  ),
            ),
          ),
        ],),

        ...

      ],)

无法从导航抽屉菜单项加载片段

1 个答案: