Visibility.Collapse не работает в WPF

Question

Visibility.Collapse не работает в моем случае. ниже - XAML. Если я попытаюсь скрыть lblCountry и cmbCountry, пробел будет отображаться между почтовыми и практическими полями. Нет возможности скрыть целую строку Grid.

<Grid> 
    <Canvas Name="canDemographic" > 

    </Canvas> 
    <Grid HorizontalAlignment="Center" VerticalAlignment="Center"> 
     <Grid.ColumnDefinitions> 
      <ColumnDefinition Width="auto"/> 
      <ColumnDefinition Width="auto"/> 
     </Grid.ColumnDefinitions> 
     <Grid.RowDefinitions> 
      <RowDefinition Height="40"/> 
      <RowDefinition Height="40" /> 
      <RowDefinition Height="40" /> 
      <RowDefinition Height="40" /> 
      <RowDefinition Height="40" /> 
      <RowDefinition Height="40"/> 
      <RowDefinition Height="40"/> 
      <RowDefinition Height="40"/> 
      <RowDefinition Height="40"/> 
      <RowDefinition Height="40"/> 
      <RowDefinition Height="40"/> 
      <RowDefinition Height="40"/> 
      <RowDefinition Height="40"/> 
     </Grid.RowDefinitions> 
     <TextBlock Width="800" Height="50" Grid.Column="0" Grid.Row="1" Grid.ColumnSpan="2" VerticalAlignment="Center" HorizontalAlignment="Center" FontFamily="Arial" FontSize="30" FontWeight="Bold" Visibility="Collapsed"> 
    Please review or enter your user information details: 
     </TextBlock> 
     <TextBlock Width="200" Height="30" Grid.Column="0" Grid.Row="2" VerticalAlignment="Center" HorizontalAlignment="Left" FontFamily="Arial" FontSize="18" FontWeight="Bold"> 
    *First Name: 
     </TextBlock> 
     <TextBlock Width="200" Height="30" Grid.Column="0" Grid.Row="3" VerticalAlignment="Center" HorizontalAlignment="Left" FontFamily="Arial" FontSize="18" FontWeight="Bold" Text=" Middle Name:"></TextBlock> 
     <TextBlock Width="200" Height="30" Grid.Column="0" Grid.Row="4" VerticalAlignment="Center" HorizontalAlignment="Left" FontFamily="Arial" FontSize="18" FontWeight="Bold"> 
    *Last Name: 
     </TextBlock> 
     <TextBlock Name="tbEmail" Width="200" Height="30" Grid.Column="0" Grid.Row="12" VerticalAlignment="Center" HorizontalAlignment="Left" FontFamily="Arial" FontSize="18" FontWeight="Bold"> 
    *Email Address: 
     </TextBlock> 
     <TextBlock Width="200" Height="30" Grid.Column="0" Grid.Row="5" VerticalAlignment="Center" HorizontalAlignment="Left" FontFamily="Arial" FontSize="18" FontWeight="Bold"> 
    *Address1: 
     </TextBlock> 
     <TextBlock Width="200" Height="30" Grid.Column="0" Grid.Row="6" VerticalAlignment="Center" HorizontalAlignment="Left" FontFamily="Arial" FontSize="18" FontWeight="Bold" Text=" Address2:"></TextBlock> 
     <TextBlock Width="200" Height="30" Grid.Column="0" Grid.Row="7" VerticalAlignment="Center" HorizontalAlignment="Left" FontFamily="Arial" FontSize="18" FontWeight="Bold"> 
    *City: 
     </TextBlock> 
     <TextBlock Width="200" Height="30" Grid.Column="0" Grid.Row="8" VerticalAlignment="Center" HorizontalAlignment="Left" FontFamily="Arial" FontSize="18" FontWeight="Bold"> 
    *State: 
     </TextBlock> 
     <TextBlock Width="200" Height="30" Grid.Column="0" Grid.Row="9" VerticalAlignment="Center" HorizontalAlignment="Left" FontFamily="Arial" FontSize="18" FontWeight="Bold"> 
    *Zip: 
     </TextBlock> 
     <TextBlock Name="lblCountry" Width="200" Grid.Column="0" Grid.ColumnSpan="2" Grid.Row="10" VerticalAlignment="Center" HorizontalAlignment="Left" FontFamily="Arial" FontSize="18" FontWeight="Bold" Text=" *Country:" Visibility="Collapsed"="></TextBlock> 
     <TextBlock Width="200" Height="30" Grid.Column="0" Grid.Row="11" VerticalAlignment="Center" HorizontalAlignment="Left" FontFamily="Arial" FontSize="18" FontWeight="Bold" Text=" Practice/Affiliation:"></TextBlock> 

     <!-- Input fields --> 
     <TextBox Name="txtFirstName" Width="200" Height="30" 
     Grid.Column="1" Grid.Row="2" VerticalAlignment="Center" HorizontalAlignment="Left" FontFamily="Arial" FontSize="18" FontWeight="Bold" MaxLength="20" TextChanged="txtFirstName_TextChanged" IsEnabled="True" /> 
     <TextBox Name="txtMiddleName" Width="200" Height="30" VerticalAlignment="Center" HorizontalAlignment="Left" FontFamily="Arial" FontSize="18" FontWeight="Bold" 
     Grid.Column="1" Grid.Row="3" MaxLength="10" IsEnabled="True" /> 
     <TextBox Name="txtLastName" Width="200" Height="30" VerticalAlignment="Center" HorizontalAlignment="Left" FontFamily="Arial" FontSize="18" FontWeight="Bold" 
     Grid.Column="1" Grid.Row="4" MaxLength="20" TextChanged="txtLastName_TextChanged" /> 
     <TextBox Name="txtEmail" Width="200" Height="30" VerticalAlignment="Center" HorizontalAlignment="Left" FontFamily="Arial" FontSize="18" FontWeight="Bold" 
     Grid.Column="1" Grid.Row="12" MaxLength="100"/> 
     <TextBox Name="txtAddress1" Width="200" Height="30" VerticalAlignment="Center" HorizontalAlignment="Left" FontFamily="Arial" FontSize="18" FontWeight="Bold" 
     Grid.Column="1" Grid.Row="5" MaxLength="100" TextChanged="txtAddress1_TextChanged" /> 
     <TextBox Name="txtAddress2" Width="200" Height="30" VerticalAlignment="Center" HorizontalAlignment="Left" FontFamily="Arial" FontSize="18" FontWeight="Bold" 
     Grid.Column="1" Grid.Row="6" MaxLength="100"/> 
     <TextBox Name="txtCity" Width="200" Height="30" VerticalAlignment="Center" HorizontalAlignment="Left" FontFamily="Arial" FontSize="18" FontWeight="Bold" 
     Grid.Column="1" Grid.Row="7" MaxLength="50" TextChanged="txtCity_TextChanged" /> 
     <TextBox Name="txtState" Width="200" Height="30" VerticalAlignment="Center" HorizontalAlignment="Left" FontFamily="Arial" FontSize="18" FontWeight="Bold" 
     Grid.Column="1" Grid.Row="8" MaxLength="50" TextChanged="txtState_TextChanged" /> 
     <TextBox Name="txtZip" Width="200" Height="30" VerticalAlignment="Center" HorizontalAlignment="Left" FontFamily="Arial" FontSize="18" FontWeight="Bold" 
     Grid.Column="1" Grid.Row="9" MaxLength="50" TextChanged="txtZip_TextChanged" /> 
     <ComboBox Name="cmbCountry" Width="200" VerticalAlignment="Center" HorizontalAlignment="Left" FontFamily="Arial" FontSize="18" FontWeight="Bold" 
     Grid.Column="0" Grid.Row="10" Grid.ColumnSpan="2" SelectionChanged="cmbCountry_SelectionChanged" ItemsSource="{Binding}" Visibility="Collapsed" /> 
     <TextBox Name="txtPractice" Width="200" Height="30" VerticalAlignment="Center" HorizontalAlignment="Left" FontFamily="Arial" FontSize="18" FontWeight="Bold" 
     Grid.Column="1" Grid.Row="11" MaxLength="50"/> 
    </Grid> 
    <Button Name="btnExit" Height="30" VerticalAlignment="Bottom" Width="100" HorizontalAlignment="Left" Margin="21,0,0,12" BorderThickness="1" FontFamily="arial" Background="LightGray" FontSize="12pt" FontWeight="Bold" Click="btnExit_Click">Back</Button> 
    <Button Name="btnNext" Height="30" VerticalAlignment="Bottom" Width="100" HorizontalAlignment="Right" Margin="0,0,21,12" BorderThickness="1" FontFamily="arial" Background="LightGray" FontSize="12pt" FontWeight="Bold" Click="btnNext_Click" IsEnabled="False" >Next</Button> 
</Grid> 
    </ScrollViewer> 

Answer 1

Я думаю, что это происходит потому, что вы явно устанавливая высоту ваших рядов (40), так что даже когда содержимое строки свернуты это занимает пространство 40. Try установив Height строки до Auto.