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从xamarin表单中的视图模型导航

xamarin.forms

0

dotnetdevcsharp · 技术社区 · 6 年前

我试图从视图模型中推送一个xamrian表单的视图,但是我不能让它真正工作当用户输入正确的用户名和密码时,它应该显示主页。

通常我会用

var stocktakepage = new StockTake();         
await Navigation.PushAsync(stocktakepage);

public  class LoginViewModel : INotifyPropertyChanged
{
    public Action DisplayInvalidLoginPrompt;
    public event PropertyChangedEventHandler PropertyChanged = delegate { };
    private string email;
    public string Email
    {
        get { return email; }
        set
        {
            email = value;
            PropertyChanged(this, new PropertyChangedEventArgs("Email"));
        }
    }
    private string password;
    public string Password
    {
        get { return password; }
        set
        {
            password = value;
            PropertyChanged(this, new PropertyChangedEventArgs("Password"));
        }
    }
    public ICommand SubmitCommand { protected set; get; }
    public LoginViewModel()
    {
        SubmitCommand = new Command(OnSubmit);
    }
    public void OnSubmit()
    {
        if (email != "handheld1" || password != "test123")
        {
            DisplayInvalidLoginPrompt();
        }else

        {




        }
    }
}

1 回复 | 直到 6 年前

1

0

dotnetdevcsharp 6 年前

我在这里找到了答案

https://forums.xamarin.com/discussion/21822/call-navigation-pushasync-from-viewmodel 但在我的登录主页上我也有这个。它的作用就像一个委托,允许您从原始调用页推送视图。

    public Login()
    {
         var vm = new LoginViewModel();
        this.BindingContext = vm;

Password.Completed += (object sender, EventArgs e) =>
{
     vm.SubmitCommand.Execute(null);


  };
}

2

0

GeralexGR 6 年前

您还可以使用下面的从 ViewModel

await App.Current.MainPage.Navigation.PushAsync(new PageName());

也

await App.Current.MainPage.Navigation.PushModalAsync(new NavigationPage(new PageName()) { BarBackgroundColor = Color.FromHex("#101010"), BarTextColor = Color.White, }, true);