How to trigger a trigger - vb.net

Question

My question relates to how to initiate as action based on user mouse input.
I have a wpf window that displays information on an organization. Some organizations are vendors in which case vendor information is displayed in another row of the grid. I use the following trigger to display/hide that row. This works as desired.
<RowDefinition>
<RowDefinition.Style>
<Style
TargetType="RowDefinition">
<Setter Property="Height" Value="0" />
<Style.Triggers>
<DataTrigger Binding="{Binding Path=IsVendor}" Value="True">
<Setter Property="Height" Value="*" />
</DataTrigger>
</Style.Triggers>
</Style>
</RowDefinition.Style>
</RowDefinition>
For an organization which is not a vendor, the user can click on a button that adds vendor information and links that new information to the organization. However, that action does not cause the trigger to fire. Is there a way to do that? Or is there a different approach that would work better?

Answer 1

In your case, I will use a converter and bind the value of Height property.
<RowDefinition>
<RowDefinition.Style>
<Style TargetType="RowDefinition">
<Setter Property="Height" Value="{Binding IsVendor, Converter={StaticResource IsVendorConverter}}" />
</Style>
</RowDefinition.Style>
</RowDefinition>
The converter will receive your boolean value (IsVendor) and returns "0" if IsVendor is false and "*" if IsVendor is true.
public class IsVendorConverter : IValueConverter
{
public object Convert(object value, Type targetType, object parameter, CultureInfo culture)
{
var isVendor = (bool)value;
if (isVendor)
{
return "*";
}
return "0";
}
public object ConvertBack(object value, Type targetType, object parameter, CultureInfo culture)
{
throw new NotImplementedException();
}
}
You didn't share your xaml, but here is a sample used with a button (clicking one button changes the height of the other one).
<Window
x:Class="WpfApp1.MainWindow"
xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
xmlns:d="http://schemas.microsoft.com/expression/blend/2008"
xmlns:local="clr-namespace:WpfApp1"
xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006">
<Window.Resources>
<local:IsVendorConverter x:Key="IsVendorConverter" />
</Window.Resources>
<StackPanel Orientation="Horizontal">
<Button Width="200" Height="{Binding IsVendor, Converter={StaticResource IsVendorConverter}}" />
<Button Width="200" Height="100" Click="Button_Click"/>
</StackPanel>
</Window>
Code Behind:
public partial class MainWindow : Window, INotifyPropertyChanged
{
public MainWindow()
{
InitializeComponent();
DataContext = this;
}
private bool _isVendor = false;
public bool IsVendor {
get { return _isVendor; }
set { _isVendor = value; OnPropertyRaised("IsVendor"); }
}
public event PropertyChangedEventHandler PropertyChanged;
private void OnPropertyRaised(string propertyname)
{
if (PropertyChanged != null)
{
PropertyChanged(this, new PropertyChangedEventArgs(propertyname));
}
}
private void Button_Click(object sender, RoutedEventArgs e)
{
IsVendor = true;
}
}