我正在使用WPF MVVM。
我有一个WCF聊天服务，应该执行某些验证操作（用户凭据），以便向聊天窗口发送消息..
这当然是在我按下“登录！”按钮的那一刻。
我想要完成的是当我按下登录并验证成功时的新视图（聊天窗口视图）。
*由于我还没有聊天视图，我们假设我的聊天视图是我的注册视图（仅供理解如何使用ICommand切换按钮点击视图的原理）
我要发布我所做的事情：
MainWindow.xaml：
<Window.Resources>
<DataTemplate DataType="{x:Type ViewModels:LoginViewModel}">
<Views:LoginView />
</DataTemplate>
<DataTemplate DataType="{x:Type ViewModels:SignUpViewModel}">
<Views:SignUpView />
</DataTemplate>
</Window.Resources>
<Grid>
<ContentControl Content="{Binding CurrentView}" />
</Grid>
MainWindow.xaml.cs：
public partial class MainWindow : Window
{
public MainWindow()
{
InitializeComponent();
DataContext = new AppViewModel();
}
}
LoginViewModel.cs
public class LoginViewModel : ViewModelBase
{
public AuthenticatedUser AuthenticatedUser { get; set; }
private string username;
public string UserName
{
get { return username; }
set {
username = value;
Notify();
}
}
private string password;
public string Password
{
get { return password; }
set
{
password = value;
Notify();
}
}
public ConsoleLog ConsoleLog { get ; set; } // TODO: StringBuilder.
public UserServiceProxy UserServiceProxy { get; set; }
public ChatServiceProxy ChatServiceProxy { get; set; }
public LoginViewModel()
{
AuthenticatedUser = AuthenticatedUser.Instance;
UserServiceProxy = new UserServiceProxy();
ChatServiceProxy = new ChatServiceProxy();
SendLoginRequestCommand = new MyCommand(SendLoginRequest);
ConsoleLog = new ConsoleLog();
ConsoleLog.Document = "Binding Checker.";
}
public ICommand SendLoginRequestCommand { get; set; }
private void SendLoginRequest()
{
LoginResponse response = UserServiceProxy.Login(new LoginRequest { UserName = UserName, Password = Password });
ConsoleLog.Document += $"{response.IsSuccess} {response.Message}";
if(response.IsSuccess == true)
{
AuthenticatedUser.Authentication = response.Authentication;
JoinServiceResponse responseFromChatService = ChatServiceProxy.JoinService(new JoinServiceRequest());
ConsoleLog.Document += responseFromChatService.Message;
/* This is where I think the view should be changed,yet no success for a few days now.
*
*
*
*
*
*/
}
}
private void LoginEventRaised(object sender, OnLoginEventArgs e)
{
ConsoleLog.Document += $"{e.UserName} has logged in.";
}
}
SignUpViewModel.cs：
public class SignUpViewModel : ViewModelBase
{
public string UserName { get; set; }
public string Password { get; set; }
public string PasswordConfirm { get; set; }
public ConsoleLog ConsoleLog { get; set; }
public UserServiceProxy UserServiceProxy { get; set; }
public ICommand OnClickSignUpCommand { get; set; }
public SignUpViewModel()
{
UserServiceProxy = new UserServiceProxy();
ConsoleLog = new ConsoleLog { Document = "Check Register."};
OnClickSignUpCommand = new MyCommand(SendSignUpRequest);
}
private void SendSignUpRequest()
{
SignUpResponse response = UserServiceProxy.SignUp(new SignUpRequest { UserName = UserName, Password = Password, PasswordConfirm = PasswordConfirm });
if(response.IsSuccess == true)
{
ConsoleLog.Document += $"{response.IsSuccess} {response.Message}";
response.AllOtherUsers.ForEach(u => ConsoleLog.Document += $"{u.UserName} Signed up.");
}
}
}
ViewModelBase.cs：
public class ViewModelBase : INotifyPropertyChanged
{
public event PropertyChangedEventHandler PropertyChanged;
public virtual void Notify([CallerMemberName] string propertyName = null)
{
PropertyChanged?.Invoke(this, new PropertyChangedEventArgs(propertyName));
}
}
AppViewModel.cs：
public class AppViewModel : ViewModelBase
{
private ViewModelBase currentView;
public ViewModelBase CurrentView
{
get { return currentView; }
set {
currentView = value;
Notify();
}
}
public ICommand ViewLoginCommand { get; }
public ICommand ViewSignUpCommand { get; }
public AppViewModel()
{
ViewLoginCommand = new MyCommand(SetCurrentViewToLoginViewModel);
ViewSignUpCommand = new MyCommand(SetCurrentViewToSignUpViewModel);
CurrentView = new LoginViewModel(); //temporary loading the first view the use will see.
}
private void SetCurrentViewToLoginViewModel()
{
CurrentView = new LoginViewModel();
}
public void SetCurrentViewToSignUpViewModel()
{
CurrentView = new SignUpViewModel();
}
}
LoginView.xaml（用户控件）：
<Grid>
<Button x:Name="login" Content="login" HorizontalAlignment="Left" Margin="292,171,0,0" VerticalAlignment="Top" Width="114" Height="33" Command="{Binding SendLoginRequestCommand}"/>
<TextBox x:Name="passwordTextBox" HorizontalAlignment="Left" Height="34" Margin="292,103,0,0" TextWrapping="Wrap" Text="{Binding Password}" VerticalAlignment="Top" Width="141"/>
<TextBox x:Name="userNameTextBox" HorizontalAlignment="Left" Height="34" Margin="292,51,0,0" TextWrapping="Wrap" Text="{Binding UserName}" VerticalAlignment="Top" Width="141"/>
<TextBlock x:Name="consoleLog" HorizontalAlignment="Left" Margin="24,33,0,0" TextWrapping="Wrap" Text="{Binding Path = ConsoleLog.Document}" VerticalAlignment="Top" Height="232" Width="218" />
<Button x:Name="logout" Content="logout" HorizontalAlignment="Left" Margin="292,232,0,0" VerticalAlignment="Top" Width="114" Height="33"/>
</Grid>
SignUpView.xaml（此代码对于这个问题并不是真的需要，但以防万一）：
<Grid>
<TextBox x:Name="textBox" HorizontalAlignment="Left" Height="30" Margin="310,24,0,0" TextWrapping="Wrap" Text="{Binding UserName}" VerticalAlignment="Top" Width="130"/>
<TextBox x:Name="textBox1" HorizontalAlignment="Left" Height="30" Margin="310,74,0,0" TextWrapping="Wrap" Text="{Binding Password}" VerticalAlignment="Top" Width="130"/>
<TextBox x:Name="textBox2" HorizontalAlignment="Left" Height="30" Margin="310,124,0,0" TextWrapping="Wrap" Text="{Binding PasswordConfirm}" VerticalAlignment="Top" Width="130"/>
<Button x:Name="register" Content="Register" HorizontalAlignment="Left" Margin="310,176,0,0" VerticalAlignment="Top" Width="130" Command="{Binding OnClickSignUpCommand}"/>
<TextBlock x:Name="textBlock" HorizontalAlignment="Left" Margin="25,10,0,0" TextWrapping="Wrap" Text="{Binding Path=ConsoleLog.Document}" VerticalAlignment="Top" Height="289" Width="253"/>
</Grid>
我知道我在这里遗漏了一些东西。可能是因为我试图解决这个问题几天所以我失去了轨道。
这是我的登录信息:(无法嵌入）
我按“登录”的那一刻，我需要下一个加载视图：
我不能为这个问题提供任何代表。不过，我真的很感激帮助。
探索网并找不到合适的问题。
答案 0 :(得分：0)
您在问题中提供了大量代码，请参阅此Minimal, Complete, and Verifiable code example 在发布你的问题之前。
如果我理解您在程序中尝试做什么，那么AppViewModel就是您的“MainNavigation”类，它负责管理所有视图并在它们之间导航。
我可以为您提供的一个解决方案是向您的LoginViewModel添加一个事件，该事件将在用户成功登录时引发。在您的AppViewModel中，您将在此活动中注册并实施一个处理程序，该处理程序会将CurrentView属性更改为您的SignUpViewModel。
LoginViewModel.cs的添加内容如下所示：
public class LoginViewModel : ViewModelBase
{
...
public delegate void UserLoginSuccessfullyHandler();
public event UserLoginSuccessfullyHandler UserLoginSuccessfullyEvent;
private void SendLoginRequest()
{
LoginResponse response = UserServiceProxy.Login(new LoginRequest { UserName = UserName, Password = Password });
ConsoleLog.Document += $"{response.IsSuccess} {response.Message}";
if(response.IsSuccess == true)
{
AuthenticatedUser.Authentication = response.Authentication;
JoinServiceResponse responseFromChatService = ChatServiceProxy.JoinService(new JoinServiceRequest());
ConsoleLog.Document += responseFromChatService.Message;
// This is where you inform the AppViewModel to change his CurrentView
if (UserLoginSuccessfullyEvent!= null)
UserLoginSuccessfullyEvent();
}
}
...
}
AppViewModel.cs的添加内容如下所示：
public class AppViewModel : ViewModelBase
{
...
public AppViewModel()
{
var loginViewModel = new LoginViewModel();
loginViewModel.UserLoginSuccessfullyEvent += new UserLoginSuccessfullyHandler(myUserLoginSuccessfullyHandler);
CurrentView = loginViewModel;
}
private void myUserLoginSuccessfullyHandler()
{
CurrentView = new SignUpViewModel();
}
...
}
您可以在此处查看有关活动的更多信息Events in C#