Vfrdtyky

I'm trying to write a simple dialog that would accept a value in a SpinEdit or a text in a TextEdit. I'm using multiple VMs and I made a selector that should view a proper control based on the logic in the c++/cli file.

XAML:

       xmlns:local="clr-namespace:asd"

       Title="{Binding Path=Title, Mode=OneTime}"



       <dx:DXWindow.Resources>



              <DataTemplate x:Key="TInputValueVM" DataType="{x:Type local:TInputValueVM}">

             <dxe:SpinEdit Height="23" Width="200"

                           Text="{Binding Value, Mode=TwoWay}"

                           Mask="{Binding Mask, Mode=OneWay}" 

                           MaxLength="{Binding Path=InputLength}" />



          </DataTemplate>



          <DataTemplate x:Key="TInputTextVM" DataType="{x:Type local:TInputTextVM}">

             <dxe:TextEdit Height="23" Width="200"

                           Text="{Binding Value, Mode=TwoWay}"

                           MaskType="RegEx" Mask="{Binding Mask, Mode=OneWay}"

                           MaxLength="{Binding Path=InputLength}"/>

          </DataTemplate>



          <local:PropertyDataTemplateSelector  x:Key="templateSelector"

             DataTemplate_Value="{StaticResource TInputValueVM}"

             DataTemplate_Text="{StaticResource TInputTextVM}" />



       </dx:DXWindow.Resources>





       <Grid>

          <Grid.RowDefinitions>

             <RowDefinition Height="Auto" />

             <RowDefinition Height="Auto" />

          </Grid.RowDefinitions>



          <StackPanel Grid.Row="0" >

             <Label x:Uid="Label" MinHeight="24" MinWidth="60" Content="Value" />

             <ContentControl Content="{Binding Path=Whoami}" ContentTemplateSelector="{StaticResource templateSelector}" />

          </StackPanel>



          <StackPanel Grid.Row="1" x:Uid="OKCancel_Buttons" Orientation="Horizontal" HorizontalAlignment="Right" VerticalAlignment="Bottom">

             <Button Height="23" x:Name="OK_Button" Click="OK_Click" Content="OK" IsDefault="True" HorizontalAlignment="Right" MinWidth="95" />

             <Button Height="23" x:Name="Cancel_Button" Click="Cancel_Click" Content="Cancel" HorizontalAlignment="Right" MinWidth="95" />

          </StackPanel>



       </Grid>

In c# I have a base VM and two VMS that extend it, one for values and one for text. The rest of the properties stay the same.

C#

namespace asd

{

   public class TInputBaseVM : ViewModelBase

   {

      private string m_sTitle;

      private string m_sMask;

      private int m_nInputLenght;

      private string m_sWhoami;



      public TInputBaseVM(string A_sTitle, string A_sMask, int A_nInputLength)

      {

         m_sTitle = A_sTitle;

         m_sMask = A_sMask;

         m_nInputLenght = A_nInputLength;

      }



      protected string Title

      {

         get { return m_sTitle; }

         set { SetProperty(ref m_sTitle, value, () => Title); }

      }

      protected string Mask

      {

         get { return m_sMask; }

         set { SetProperty(ref m_sMask, value, () => Mask); }

      }



      protected int InputLength

      {

         get { return m_nInputLenght; }

         set { SetProperty(ref m_nInputLenght, value, () => InputLength); }

      }



      protected string Whoami

      {

         get { return m_sWhoami; }

         set { SetProperty(ref m_sWhoami, value, () => Whoami); }

      }

   }



   public class TInputValueVM : TInputBaseVM

   {

      public TInputValueVM(string A_sTitle, string A_sMask, int A_nInputLength, double A_nValue) : base(A_sTitle, A_sMask, A_nInputLength)

      {

         Value = A_nValue;

         Whoami = "Value";

      }



      private double m_nValue;

      public double Value

      {

         get { return m_nValue; }

         set { SetProperty(ref m_nValue, value, () => Value); }

      }

   }



   public class TInputTextVM : TInputBaseVM

   {

      public TInputTextVM(string A_sTitle, string A_sMask, int A_nInputLength, string A_sValue) : base(A_sTitle, A_sMask, A_nInputLength)

      {

         Value = A_sValue;

         Whoami = "Text";

      }



      private string m_sValue;

      public string Value

      {

         get { return m_sValue; }

         set { SetProperty(ref m_sValue, value, () => Value); }

      }

   }



   public class PropertyDataTemplateSelector : DataTemplateSelector

   {

      public DataTemplate DataTemplate_Value { get; set; }

      public DataTemplate DataTemplate_Text { get; set; }



      public override DataTemplate SelectTemplate(object item, DependencyObject container)

      {

         var selector = item as string;



         if(selector == "Value")

            return DataTemplate_Value;

         return DataTemplate_Text;

      }

   }



}

In c++/cli I create an object of a proper VM and I'd like the WPF to automatically update the view to either spinedit or textedit, however I'm not sure how to properly bind the properties from the C#. If I explicitly type 'Value' in the Content property of the ContentControl then it displays the spinEdit but I don't know how to bind it so it automatically takes the correct property.

EDIT: I'm adding c++/cli code to show how I choose different VMs

C++/cli:

bool TSignalNumberPositionDialogCLR::StartDialog(TSignalNumberPositionSupport& A_Attributes, HWND A_hwndParent, LPTSTR String)

{

   try

   {

      TInputValueVM ^oExchange_Value;

      TInputTextVM ^oExchange_Text;



      int inputFormat = A_Attributes.GetInputFormat();



      if(inputFormat)

         oExchange_Text = gcnew TInputTextVM(gcnew System::String(A_Attributes.GetTitle()), gcnew System::String(A_Attributes.GetMask()),

            A_Attributes.GetInputLength(), gcnew System::String(A_Attributes.GetInitialText()));

      else

         oExchange_Value = gcnew TInputValueVM(gcnew System::String(A_Attributes.GetTitle()), gcnew System::String(A_Attributes.GetMask()),

            A_Attributes.GetInputLength(), A_Attributes.GetInitialValue());





      Dialogs::TSignalNumberPositionDialog^ dialog = gcnew Dialogs::TSignalNumberPositionDialog();



      if(inputFormat)

         dialog->DataContext = oExchange_Text;

      else

         dialog->DataContext = oExchange_Value;



      dialog->ShowDialog();



      if(dialog->DialogResult)

      {

         CString nValue;



         if(inputFormat)

            nValue = oExchange_Text->Value;

         else

            nValue = ((Decimal)oExchange_Value->Value).ToString("F2", CultureInfo::InvariantCulture);



         A_Attributes.UpdateValue(nValue, String, A_Attributes.GetInputLength());

         return true;

      }



      return false;

   }

   catch(Exception^ e)

   {

      e;

   }

}

based on the 'inputFormat' variable I want to display different controls in the dialog.

EDIT: Based on @Clemens comments I got rid of the selector sectionand the x:Key property in the DataTemplates. I changed the content opf the Content property to Content="{Binding}" and it somehow works. The moment I create a VM it selects the correct one.

Based on your comment. Let me improve my answer. As you are facing issue in VM selection. so plesae concentrate how I assigned VM to datatemplate. Although it is done in very basic way, you can handle it if you you are using MVVM packages.
I have created 2 data template and 2 vms and each vm is bound to datatemplate. To verify, I have a combobox, which will select datatemplate based on selected value.

Here is Sample VM

public class VM : System.ComponentModel.INotifyPropertyChanged

{

    private string title;

    private SolidColorBrush background;



    public string Title { get => title; set { title = value; RaisePropertyChanged(); } }

    public SolidColorBrush Background { get => background; set { background = value; RaisePropertyChanged(); } }



    public event PropertyChangedEventHandler PropertyChanged;

    private void RaisePropertyChanged([System.Runtime.CompilerServices.CallerMemberName] string name = "")

    {

        PropertyChanged?.Invoke(this, new PropertyChangedEventArgs(name));

    }

}



public class VM1: VM

{

    public VM1()

    {

        Title = "This is VM1";

        Background = Brushes.Yellow;

    }

}



public class VM2: VM

{

    public VM2()

    {

        Title = "This is VM2";

        Background = Brushes.Orange;

    }

}

Now check for resources

<local:VM1 x:Key="VM1"/>

    <local:VM2 x:Key="VM2"/>



    <DataTemplate x:Key="DT1">

        <Grid DataContext="{StaticResource VM1}">

            <TextBlock Text="{Binding Title}" Background="{Binding Background}"/>

        </Grid>

    </DataTemplate>

    <DataTemplate x:Key="DT2">

        <Grid DataContext="{StaticResource VM2}">

            <TextBlock Text="{Binding Title}" Background="{Binding Background}"/>

        </Grid>

    </DataTemplate>



    <Style TargetType="ContentControl" x:Key="contentStyle">

        <Style.Triggers>

            <DataTrigger Binding="{Binding ElementName=cmbo, Path=SelectedValue}" Value="Template1">

                <Setter Property="ContentTemplate" Value="{StaticResource DT1}" />

            </DataTrigger>

            <DataTrigger Binding="{Binding ElementName=cmbo, Path=SelectedValue}" Value="Template2">

                <Setter Property="ContentTemplate" Value="{StaticResource DT2}" />

            </DataTrigger>

        </Style.Triggers>

    </Style>

and finally I have combobox and content control just to verify

    <ComboBox Name="cmbo"/>



        <ContentControl  Style="{StaticResource contentStyle}"/>

where cmbo.ItemsSource = new List { "Template1", "Template2" };

Hope you got the point