WPF C # Hide Controls on Application Launch

Question

I created a start page that loads when the application starts, but also shows my tabcontrol (two tabs for editing and diagrams).

How to hide tabcontrol elements at startup and show it only when the user selects a file → new?

Many thanks!

Xaml:

<TabControl Height="Auto" Name="tabControl1" Width="Auto">
            <TabItem Header="Diagram" Name="DiagramTab"></TabItem>
            <TabItem Header="Rulebase" Name="RuleTab" >
              <Grid>
               <TextBox Height="Auto" Name="RuleText" Width="Auto" Text="" AcceptsTab="True" AcceptsReturn="True" VerticalScrollBarVisibility="Auto" GotFocus="FocusChanged" KeyDown="ContentChanged" HorizontalScrollBarVisibility="Visible" />
              </Grid>
           </TabItem>
        </TabControl>

Here is my file -> new menu item:

 private void NewItem(object sender, RoutedEventArgs e)
    {
        ProcessNewCommand();
    }

private void ProcessNewCommand()
    {
        if (dataChanged)
        {
            string sf = SaveFirst();
            if (sf != "Cancel")
            {
                ClearState();                    
            }
        }
        else
        {
            ClearState();
        }
    }

Style:

<Style TargetType="TabItem" >
        <Setter Property="Template">
            <Setter.Value>
                <ControlTemplate TargetType="TabItem">
                    <Grid>
                        <Border 
                            Name="Border"
                            Background="LightBlue"
                            BorderBrush="Black" 
                            BorderThickness="0" 
                            CornerRadius="6,6,0,0" >
                 <ContentPresenter x:Name="ContentSite"
                            VerticalAlignment="Center"
                            HorizontalAlignment="Center"
                            ContentSource="Header"
                            Margin="12,2,12,2"/>
                        </Border>
                   </Grid>
         <ControlTemplate.Triggers>
                        <Trigger Property="IsSelected" Value="True">
                            <Setter TargetName="Border" Property="Background" Value="LightBlue" />
                        </Trigger>
                        <Trigger Property="IsSelected" Value="False">
                            <Setter TargetName="Border" Property="Background" Value="LightGray" />
                        </Trigger>
                    </ControlTemplate.Triggers>
                </ControlTemplate>
            </Setter.Value>
        </Setter>
    </Style>

Answer 1

In these scenarios, there is usually ProjectViewModel(or ProjectModel) that is added as DataContextcontaining Window. TabControlmay have those tabs bound to data context items.

public class ProjectViewModel : YourViewModelBase
{
    public EditingViewModel Editor { ... }

    public DiagramingViewModel Diagram { ... }
}

, NewCommand, this.DataContext = new ProjectViewModel(). .

<Window.Resources>
    <Style x:Key="HideWithoutDataContext">
        <Setter Property="UIElement.Visibility" Value="Visible" />
        <Style.Triggers>
            <DataTrigger Binding="{Binding}" Value="{x:Null}">
                <Setter Property="UIElement.Visibility" Value="Collapsed" />
            </DataTrigger>
        </Style.Triggers>
    </Style>
</Window.Resources>
<TabControl>
    <TabItem Header="Start Page">
       ...
    </TabItem>
    <TabItem Header="Editor"
             DataContext="{Binding Editor}"
             Style="{DynamicResource HideWithoutDataContext}"/>
    <TabItem Header="Diagram"
             DataContext="{Binding Diagram}"
             Style="{DynamicResource HideWithoutDataContext}"/>
</TabControl>

Answer 2

Tab Visibility , , , "".