Xamarin Android底部逐步杆可以工作。请帮助我

Question

我正在运行该程序是休息模式。我的代码中有什么问题对我有帮助。

UI仅很好，但是在添加NavigationEmselectectected事件之后，该程序是断点模式。

 private void BottomNavigation_NavigationItemSelected(object sender, BottomNavigationView.NavigationItemSelectedEventArgs e)
    {
        //LoadFragment(e.Item.ItemId);
    }



void LoadFragment(int id)
    {
        Android.Support.V4.App.Fragment fragment = null;
        switch (id)
        {
            case Resource.Id.menu_Meeting:
                fragment = MeetingFragment.NewInstance();
                break;
            case Resource.Id.menu_Project:
                fragment = ProjectFragment.NewInstance();
                break;
            case Resource.Id.menu_Account:
                fragment = AccountFragment.NewInstance();
                break;
        }
        if (fragment == null)
            return;

        SupportFragmentManager.BeginTransaction()
           .Replace(Resource.Id.content_frame, fragment)
           .Commit();
    }

在这里断开模式错误 请帮我！

Answer 1

根据您的代码，我实现了此功能。

您可以参考以下代码：

public class MainActivity : AppCompatActivity
{

    private SupportFragment mCurrentFragment;
    private MeetingFragment mFragment1;
    private ProjectFragment mFragment2;
    private AccountFragment mFragment3;
    private Stack<SupportFragment> mStackFragment;
    BottomNavigationView bottomNavigation;


    protected override void OnCreate(Bundle savedInstanceState)
    {
        base.OnCreate(savedInstanceState);
        Xamarin.Essentials.Platform.Init(this, savedInstanceState);
        // Set our view from the "main" layout resource
        SetContentView(Resource.Layout.activity_main);

        bottomNavigation = FindViewById<BottomNavigationView>(Resource.Id.bottom_navigation);

        bottomNavigation.NavigationItemSelected += (s, e) =>
        {
            Android.Support.V4.App.Fragment fragment = null;
            switch (e.Item.ItemId)
            {
                case Resource.Id.menu_Meeting:
                    fragment = new MeetingFragment();
                    break;
                case Resource.Id.menu_Project:
                    fragment = new ProjectFragment();
                    break;
                case Resource.Id.menu_Account:
                    fragment = new AccountFragment();
                    break;
            }
            SupportFragmentManager.BeginTransaction()
            .Replace(Resource.Id.content_frame, fragment)
            .Commit();

            return;
        };

        mFragment1 = new MeetingFragment();
        mFragment2 = new ProjectFragment();
        mFragment3 = new AccountFragment();

        mStackFragment = new Stack<SupportFragment>();

        var trans = SupportFragmentManager.BeginTransaction();
        trans.Add(Resource.Id.content_frame, mFragment3, "Fragment3");//NOT bottom_navigation, it must be the container
        trans.Hide(mFragment3);
        trans.Add(Resource.Id.content_frame, mFragment2, "Fragment2");
        trans.Hide(mFragment2);
        trans.Add(Resource.Id.content_frame, mFragment1, "Fragment1");
        trans.Commit();

        mCurrentFragment = mFragment1;

    }
}