当从一个窗口导航到另一个窗口时，数值没有得到

Question

如果导航到另一个窗口进行更新，它将所选行重置为null ..如果更新是在同一主页完成的，那么正在获取该值并且可以更新。如果我甲肝不同的视图模型为每个视图，然后在该甲肝不同的视图模型一个新窗口中显示的数据，我怎么能做到这一点一个太..

这是我的员工视图模型代码

namespace EmployeeRegistration 
{ 
    class EmployeeViewModel : WindowItem, INotifyPropertyChanged, IDataErrorInfo 
    { 

     #region Declarations 
     SqlConnection sqlConnection = null; 
     SqlCommand insertCommand = null; 
     SqlCommand selectCommand = null; 
     SqlCommand updateCommand = null; 
     SqlDataAdapter sqlAdapter = null; 
     DataTable employeeTable = null; 
     DataSet sqlDataSet = null; 
     EmployeeModel employee; 
     private ICommand newEmployeeCommand; 
     private ICommand searchEmployeeCommand; 
     private ICommand saveEmployeeCommand; 
     private ICommand getEmployeeCommand; 
     public ICommand bindControlValueCommand; 
     public ICommand selectEmployeeCommand; 
     public ICommand updateDetailsCommand; 
     private Window window; 
     #endregion 

     #region Constructors 
     public EmployeeViewModel() 
     { 
      employee = new EmployeeModel(); 
      SaveEmployeeCommand = new RelayCommand(new Action(saveEmployeeDetail)); 
      SearchEmployeeCommand = new RelayCommand(new Action(searchEmployee)); 
      GetEmployeeCommand = new RelayCommand(new Action(getEmployee)); 
      SelectEmployeeCommand = new RelayCommand(new Action(selectEmployeeDetails)); 
      NewEmployeeCommand = new RelayCommand(new Action(newEmployeeWindow)); 
      UpdateDetailsCommand = new RelayCommand(new Action(updateEmployeeDetails)); 
      bindControlValueCommand = new RelayCommand(new Action(bindControlValues)); 
      Id = WindowsId.MainWindow; 
      Function = ProcessMessage; 
      WindowsManager.Add(Id, Function); 
     } 
     #endregion 

     #region Properties 
     //public EmployeeModel _Employee; 
     //public EmployeeModel Employee 
     //{ 
     // get 
     // { 
     //  return _Employee; 
     // } 
     // set 
     // { 
     //  _Employee = value; 
     //  OnPropertyChanged("Employee"); 
     // } 
     //} 

     public DataRowView selectedEmployee; 
     public DataRowView SelectedEmployee 
     { 
      get 
      { 
       return selectedEmployee; 
      } 
      set 
      { 
       selectedEmployee = value; 
       OnPropertyChanged("SelectedEmployee"); 
      } 
     } 
     private DataTable employeeDatatable; 
     public DataTable EmployeeDatatable 
     { 
      get { return employeeDatatable; } 
      set 
      { 
       employeeDatatable = value; 
       OnPropertyChanged("EmployeeDatatable"); 

      } 
     } 
     public int Emp_ID 
     { 
      get 
      { 
       return employee.Emp_ID; 
      } 
      set 
      { 
       employee.Emp_ID = value; 
       OnPropertyChanged("Emp_ID"); 
      } 
     } 
     public string FirstName 
     { 
      get 
      { 
       return employee.FirstName; 
      } 
      set 
      { 
       employee.FirstName = value; 
       OnPropertyChanged("FirstName"); 
       //this.DetailView = new HomeViewModel(value); 
      } 
     } 
     public string LastName 
     { 
      get 
      { 
       return employee.LastName; 
      } 
      set 
      { 
       employee.LastName = value; 
       OnPropertyChanged("LastName"); 
      } 
     } 
     public DateTime Dob 
     { 
      get 
      { 
       return employee.Dob; 
      } 
      set 
      { 
       employee.Dob = value; 
       OnPropertyChanged("Dob"); 
       OnPropertyChanged("Age"); 
      } 
     } 
     public int Age 
     { 
      get 
      { 
       return employee.Age = DateTime.Today.Year - Dob.Year; 
      } 
      set 
      { 
       employee.Age = value; 
       OnPropertyChanged("Age"); 
      } 

     } 
     public string Street1 
     { 
      get 
      { 
       return employee.Street1; 
      } 
      set 
      { 
       employee.Street1 = value; 
       OnPropertyChanged("Street1"); 
      } 
     } 
     public string Street2 
     { 
      get 
      { 
       return employee.Street2; 
      } 
      set 
      { 
       employee.Street2 = value; 
       OnPropertyChanged("Street2"); 
      } 
     } 
     public string City 
     { 
      get 
      { 
       return employee.City; 
      } 
      set 
      { 
       employee.City = value; 
       OnPropertyChanged("City"); 
      } 
     } 
     public string State 
     { 
      get 
      { 
       return employee.State; 
      } 
      set 
      { 
       employee.State = value; 
       OnPropertyChanged("State"); 
      } 
     } 
     public string ZipCode 
     { 
      get 
      { 
       return employee.ZipCode; 
      } 
      set 
      { 
       employee.ZipCode = value; 
       OnPropertyChanged("ZipCode"); 
      } 
     } 
     public string PhoneNumber 
     { 
      get 
      { 
       return employee.PhoneNumber; 
      } 
      set 
      { 
       employee.PhoneNumber = value; 
       OnPropertyChanged("PhoneNumber"); 
      } 
     } 
     public string MobileNumber 
     { 
      get 
      { 
       return employee.MobileNumber; 
      } 
      set 
      { 
       employee.MobileNumber = value; 
       OnPropertyChanged("MobileNumber"); 
      } 
     } 
     public string Email 
     { 
      get 
      { 
       return employee.Email; 
      } 
      set 
      { 
       employee.Email = value; 
       OnPropertyChanged("Email"); 
      } 
     } 
     public string Web 
     { 
      get 
      { 
       return employee.Web; 
      } 
      set 
      { 
       employee.Web = value; 
       OnPropertyChanged("Web"); 
      } 
     } 

     #endregion 

     #region Commands 
     public ICommand UpdateDetailsCommand 
     { 
      get 
      { 
       return updateDetailsCommand; 
      } 
      set 
      { 
       updateDetailsCommand = value; 
      } 
     } 
     public ICommand SelectEmployeeCommand 
     { 
      get 
      { 
       return selectEmployeeCommand; 
      } 
      set 
      { 
       selectEmployeeCommand = value; 
      } 
     } 
     public ICommand SaveEmployeeCommand 
     { 
      get 
      { 
       return saveEmployeeCommand; 
      } 
      set 
      { 
       saveEmployeeCommand = value; 
      } 
     } 
     public ICommand SearchEmployeeCommand 
     { 
      get 
      { 
       return searchEmployeeCommand; 
      } 
      set 
      { 
       searchEmployeeCommand = value; 
      } 
     } 

     public ICommand GetEmployeeCommand 
     { 
      get 
      { 
       return getEmployeeCommand; 
      } 
      set 
      { 
       getEmployeeCommand = value; 
      } 
     } 
     public ICommand NewEmployeeCommand 
     { 
      get 
      { 
       return newEmployeeCommand; 
      } 
      set 
      { 
       newEmployeeCommand = value; 
      } 
     } 
     public ICommand BindControlValueCommand 
     { 
      get 
      { 
       return bindControlValueCommand; 
      } 
      set 
      { 
       bindControlValueCommand = value; 
      } 
     } 
     #endregion 

     #region INotifyPropertyChanged Members 
     public event PropertyChangedEventHandler PropertyChanged; 
     private void OnPropertyChanged(string propertyName) 
     { 
      if (PropertyChanged != null) 
      { 
       PropertyChanged(this, new PropertyChangedEventArgs(propertyName)); 
      } 
     } 
     #endregion 

     #region SubMethods 
     public void newEmployeeWindow() 
     { 
      WindowsManager.SendMessage(WindowsId.MainWindow, null, ActionId.OpenWindow); 
     } 

     private bool ProcessMessage(object args, ActionId action) 
     { 
      if (action == ActionId.OpenWindow) 
      { 
       if (window == null) 
       { 
        window = new UpdateEmployeeDetails(); 
       } 
       window.Show(); 
       return true; 
      } 
      if (action == ActionId.CloseWindow) 
      { 
       if (window == null) 
        return false; 
       window.Close(); 
       window = null; 
       return true; 
      } 
      return false; 
     } 

     private void bindControlValues() 
     { 

      this.Emp_ID = Convert.ToInt32(SelectedEmployee.Row.ItemArray[0]); 
      try 
      { 
       sqlConnection = new SqlConnection(Connection.connectionstring); 
       sqlConnection.Open(); 
       selectCommand = new SqlCommand(AppConstants.StoredProcedures.GetDataProcedure, sqlConnection); 
       selectCommand.CommandType = CommandType.StoredProcedure; 
       selectCommand.Parameters.Add(AppConstants.Parameters.Emp_ID, SqlDbType.Int).Value = this.Emp_ID; ; 

       sqlAdapter = new SqlDataAdapter(selectCommand); 
       sqlDataSet = new DataSet(); 
       sqlAdapter.Fill(sqlDataSet); 
       this.FirstName = sqlDataSet.Tables[0].Rows[0][1].ToString(); 
       this.LastName = sqlDataSet.Tables[0].Rows[0][2].ToString(); 
       this.Dob = Convert.ToDateTime(sqlDataSet.Tables[0].Rows[0][3].ToString()); 
       this.Age = Convert.ToInt32(sqlDataSet.Tables[0].Rows[0][4].ToString()); 
       this.Street1 = sqlDataSet.Tables[0].Rows[0][5].ToString(); 
       this.Street2 = sqlDataSet.Tables[0].Rows[0][6].ToString(); 
       this.City = sqlDataSet.Tables[0].Rows[0][7].ToString(); 
       this.State = sqlDataSet.Tables[0].Rows[0][8].ToString(); 
       this.ZipCode = sqlDataSet.Tables[0].Rows[0][9].ToString(); 
       this.PhoneNumber = sqlDataSet.Tables[0].Rows[0][10].ToString(); 
       this.MobileNumber = sqlDataSet.Tables[0].Rows[0][11].ToString(); 
       this.Email = sqlDataSet.Tables[0].Rows[0][12].ToString(); 
       this.Web = sqlDataSet.Tables[0].Rows[0][13].ToString(); 
      } 

     } 

     private void selectEmployeeDetails() 
     { 

      WindowsManager.SendMessage(WindowsId.MainWindow, null, ActionId.OpenWindow); 

     } 

     public void updateEmployeeDetails() 
     { 
      this.Emp_ID = Convert.ToInt32(SelectedEmployee.Row.ItemArray[0]); 
      try 
      { 
       SqlConnection sqlConnection = new SqlConnection(Connection.connectionstring); 
       sqlConnection.Open(); 

       updateCommand = new SqlCommand(AppConstants.StoredProcedures.UpdateProcedure, sqlConnection); 
       updateCommand.CommandType = CommandType.StoredProcedure; 

       updateCommand.Parameters.Add(AppConstants.Parameters.Emp_ID, SqlDbType.Int).Value = this.Emp_ID; 
       updateCommand.Parameters.Add(AppConstants.Parameters.FirstName, SqlDbType.VarChar).Value = this.FirstName; 
       updateCommand.Parameters.Add(AppConstants.Parameters.LastName, SqlDbType.VarChar).Value = this.LastName; 
       updateCommand.Parameters.Add(AppConstants.Parameters.Dob, SqlDbType.VarChar).Value = Convert.ToDateTime(this.Dob); 
       updateCommand.Parameters.Add(AppConstants.Parameters.Age, SqlDbType.Int).Value = Convert.ToInt32(this.Age); 
       updateCommand.Parameters.Add(AppConstants.Parameters.Street1, SqlDbType.VarChar).Value = this.Street1; 
       updateCommand.Parameters.Add(AppConstants.Parameters.Street2, SqlDbType.VarChar).Value = this.Street2; 
       updateCommand.Parameters.Add(AppConstants.Parameters.City, SqlDbType.VarChar).Value = this.City; 
       updateCommand.Parameters.Add(AppConstants.Parameters.State, SqlDbType.VarChar).Value = this.State; 
       updateCommand.Parameters.Add(AppConstants.Parameters.ZipCode, SqlDbType.BigInt).Value = Convert.ToInt64(this.ZipCode); 
       updateCommand.Parameters.Add(AppConstants.Parameters.PhoneNumber, SqlDbType.BigInt).Value = Convert.ToInt64(this.PhoneNumber); 
       updateCommand.Parameters.Add(AppConstants.Parameters.MobileNumber, SqlDbType.BigInt).Value = Convert.ToInt64(this.MobileNumber); 
       updateCommand.Parameters.Add(AppConstants.Parameters.Email, SqlDbType.VarChar).Value = this.Email; 
       updateCommand.Parameters.Add(AppConstants.Parameters.Web, SqlDbType.VarChar).Value = this.Web; 
       int count = updateCommand.ExecuteNonQuery(); 
       if (count > 0) 
       { 
        MessageBox.Show("You Have Updated Successfully"); 
       } 
      } 
      catch(Exception ex) 
      { 
       throw ex; 
      } 
      finally 
      { 
       sqlConnection.Close(); 
       updateCommand.Dispose(); 
      } 

     } 

     public void saveEmployeeDetail() 
     { 
      int count1 = 0; 
      try 
      { 
       sqlConnection = new SqlConnection(Connection.connectionstring); 
       sqlConnection.Open(); 
       insertCommand = new SqlCommand(AppConstants.StoredProcedures.InsertProcedure, sqlConnection); 
       insertCommand.CommandType = CommandType.StoredProcedure; 

       insertCommand.Parameters.Add(AppConstants.Parameters.FirstName, SqlDbType.VarChar).Value = this.FirstName; 
       insertCommand.Parameters.Add(AppConstants.Parameters.LastName, SqlDbType.VarChar).Value = this.LastName; 
       insertCommand.Parameters.Add(AppConstants.Parameters.Dob, SqlDbType.DateTime).Value = Convert.ToDateTime(this.Dob); 
       insertCommand.Parameters.Add(AppConstants.Parameters.Age, SqlDbType.Int).Value = Convert.ToInt32(this.Age); 
       insertCommand.Parameters.Add(AppConstants.Parameters.Street1, SqlDbType.VarChar).Value = this.Street1; 
       insertCommand.Parameters.Add(AppConstants.Parameters.Street2, SqlDbType.VarChar).Value = this.Street2; 
       insertCommand.Parameters.Add(AppConstants.Parameters.City, SqlDbType.VarChar).Value = this.City; 
       insertCommand.Parameters.Add(AppConstants.Parameters.State, SqlDbType.VarChar).Value = this.State; 
       insertCommand.Parameters.Add(AppConstants.Parameters.ZipCode, SqlDbType.BigInt).Value = Convert.ToInt64(this.ZipCode); 
       insertCommand.Parameters.Add(AppConstants.Parameters.PhoneNumber, SqlDbType.BigInt).Value = Convert.ToInt64(this.PhoneNumber); 
       insertCommand.Parameters.Add(AppConstants.Parameters.MobileNumber, SqlDbType.BigInt).Value = Convert.ToInt64(this.MobileNumber); 
       insertCommand.Parameters.Add(AppConstants.Parameters.Email, SqlDbType.VarChar).Value = this.Email; 
       insertCommand.Parameters.Add(AppConstants.Parameters.Web, SqlDbType.VarChar).Value = this.Web; 
       count1 = insertCommand.ExecuteNonQuery(); 

       if (count1 > 0) 
       { 
        MessageBox.Show(AppConstants.Messages.SuccessMessages.InsertSuccess); 
       } 
      } 
      catch (Exception ex) 
      { 
       throw ex; 
      } 
      finally 
      { 
       sqlConnection.Close(); 
       insertCommand.Dispose(); 
      } 
     } 

     public void getEmployee() 
     { 
      try 
      { 
       sqlConnection = new SqlConnection(Connection.connectionstring); 
       sqlConnection.Open(); 

       selectCommand = new SqlCommand(AppConstants.StoredProcedures.SelectProcedure, sqlConnection); 
       selectCommand.CommandType = CommandType.StoredProcedure; 
       sqlAdapter = new SqlDataAdapter(selectCommand); 
       employeeTable = new DataTable(); 
       sqlAdapter.Fill(employeeTable); 
       EmployeeDatatable = null; 
       EmployeeDatatable = employeeTable; 
      } 

     } 

     public void searchEmployee() 
     { 
      //employee.Emp_ID = SelectedEmployee.Row["Emp_ID"].ToString(); 
      sqlConnection = new SqlConnection(Connection.connectionstring); 
      sqlConnection.Open(); 

      //Searching the Employee using Stored Procedure by passing the Firstname as parameter 
      selectCommand = new SqlCommand(AppConstants.StoredProcedures.SearchProcedure, sqlConnection); 
      selectCommand.CommandType = CommandType.StoredProcedure; 
      selectCommand.Parameters.Add(AppConstants.Parameters.FirstName, SqlDbType.VarChar).Value = employee.FirstName; 
      selectCommand.ExecuteNonQuery(); 

      sqlAdapter = new SqlDataAdapter(); 
      sqlAdapter.SelectCommand = selectCommand; 
      employeeTable = new DataTable(); 
      sqlAdapter.Fill(employeeTable); 
      EmployeeDatatable = null; 
      EmployeeDatatable = employeeTable; 
     } 
     #endregion 
    } 
} 

这是我的家xaml

<Window x:Class="EmployeeRegistration.Home" 
     xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation" 
     xmlns:sdk="http://schemas.microsoft.com/winfx/2006/xaml/presentation/sdk" 
     xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml" 
     xmlns:cmd="clr-namespace:GalaSoft.MvvmLight.Command;assembly=GalaSoft.MvvmLight.Extras.WPF4" 
     xmlns:i="clr-namespace:System.Windows.Interactivity;assembly=System.Windows.Interactivity" 
     xmlns:View="clr-namespace:EmployeeRegistration" 
     Title="Home" Height="595" Width="1096"> 
    <Window.DataContext> 
     <View:EmployeeViewModel></View:EmployeeViewModel> 
    </Window.DataContext> 
    <i:Interaction.Triggers> 
     <i:EventTrigger EventName="Loaded"> 
      <cmd:EventToCommand Command="{Binding GetEmployeeCommand}" /> 
     </i:EventTrigger> 
    </i:Interaction.Triggers> 
    <Window.Resources> 
     <Style TargetType="Control" x:Key="myErrorTemplate"> 
      <Setter Property="Validation.ErrorTemplate"> 
       <Setter.Value> 
        <ControlTemplate> 
         <Border BorderBrush="Red" BorderThickness="1" CornerRadius="2.75" Grid.Column="0"> 
          <AdornedElementPlaceholder Name="MyControl" Grid.Column="0"/> 
         </Border> 
        </ControlTemplate> 
       </Setter.Value> 
      </Setter> 
      <Style.Triggers> 
       <Trigger Property="Validation.HasError" Value="true"> 
        <Setter Property="ToolTip" 
       Value="{Binding RelativeSource={x:Static RelativeSource.Self}, 
       Path=(Validation.Errors)[0].ErrorContent}"/> 
       </Trigger> 
      </Style.Triggers> 
     </Style> 
     <Style TargetType="TextBox" BasedOn="{StaticResource myErrorTemplate}" /> 
    </Window.Resources> 
    <Grid Height="984" Width="1089"> 
     <Grid.RowDefinitions> 
      <RowDefinition Height="65"></RowDefinition> 
      <RowDefinition Height="36"></RowDefinition> 
      <RowDefinition Height="35" /> 
      <RowDefinition Height="44"></RowDefinition> 
      <RowDefinition Height="45" /> 
      <RowDefinition Height="49" /> 
      <RowDefinition Height="56" /> 
      <RowDefinition Height="43" /> 
      <RowDefinition Height="40" /> 
      <RowDefinition Height="37"></RowDefinition> 
      <RowDefinition Height="39*" /> 
      <RowDefinition Height="42*" /> 
      <RowDefinition Height="453*" /> 
     </Grid.RowDefinitions> 
     <Grid.ColumnDefinitions> 
      <ColumnDefinition Width="538"></ColumnDefinition> 
      <ColumnDefinition Width="121" /> 
      <ColumnDefinition Width="149" /> 
      <ColumnDefinition Width="110" /> 
      <ColumnDefinition Width="182" /> 
     </Grid.ColumnDefinitions> 


    </Grid> 

</Window> 

这是我更新窗口XAML

<Window x:Class="EmployeeRegistration.UpdateEmployeeDetails" 
     xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation" 
     xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml" 
     xmlns:cmd="clr-namespace:GalaSoft.MvvmLight.Command;assembly=GalaSoft.MvvmLight.Extras.WPF4" 
     xmlns:i="clr-namespace:System.Windows.Interactivity;assembly=System.Windows.Interactivity" 
     xmlns:View="clr-namespace:EmployeeRegistration" 
     Title="UpdateEmployeeDetails" Height="575" Width="614"> 
    <Window.DataContext> 
     <View:EmployeeViewModel></View:EmployeeViewModel> 
    </Window.DataContext> 
    <i:Interaction.Triggers> 
     <i:EventTrigger EventName="Loaded"> 
      <cmd:EventToCommand Command="{Binding BindControlValueCommand}" /> 
     </i:EventTrigger> 
    </i:Interaction.Triggers> 

Answer 1

尝试传递你的ProcessMessage命令的DataContext到新窗口：

private bool ProcessMessage(object args, ActionId action) 
    { 
     if (action == ActionId.OpenWindow) 
     { 
      if (window == null) 
      { 
       window = new UpdateEmployeeDetails(); 
       window.DataContext = this; 
      } 
      window.Show(); 
      return true; 
     } 
     if (action == ActionId.CloseWindow) 
     { 
      if (window == null) 
       return false; 
      window.Close(); 
      window = null; 
      return true; 
     } 
     return false; 
    }