I am trying to learn how to use the IValueConverter to enable/disable controls (in this case a button) using the boolean-property of an item selected in a listbox. The button in question is the "TestButton". I believe I have the XAML for it setup correctly but it does not enable when I add and select a user defined item or disable when I select one of the other items in the listbox. The listbox contains a list of "Drink" objects that can be added to. When one is added it becomes a user defined item. Now I believe I am missing something but I am not sure what. Any help will be appreciated.
ViewModel code here:
<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:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"
xmlns:local="clr-namespace:WpfApp1"
mc:Ignorable="d"
Title="MainWindow" Height="450" Width="800">
<Window.Resources>
<local:Drinks x:Key="Drink"/>
<local:EnableConverter x:Key="EnableConverter"/>
<BooleanToVisibilityConverter x:Key="BoolToVis"/>
<ControlTemplate x:Key="validationTemplate">
<DockPanel>
<TextBlock Foreground="Red" FontSize="20">!</TextBlock>
<AdornedElementPlaceholder/>
</DockPanel>
</ControlTemplate>
<Style x:Key="textStyleTextBox" TargetType="TextBox">
<Setter Property="Foreground" Value="#333333" />
<Setter Property="MaxLength" Value="40" />
<Setter Property="Width" Value="392" />
<Style.Triggers>
<Trigger Property="Validation.HasError" Value="true">
<Setter Property="ToolTip" Value="{Binding RelativeSource={RelativeSource Self}, Path=(Validation.Errors)[0].ErrorContent}"/>
</Trigger>
</Style.Triggers>
</Style>
</Window.Resources>
<Grid>
<Grid.ColumnDefinitions>
<ColumnDefinition Width="*"/>
<ColumnDefinition Width="*"/>
</Grid.ColumnDefinitions>
<Grid.RowDefinitions>
<RowDefinition Height="*" />
</Grid.RowDefinitions>
<ListBox x:Name="DrinksListBox" HorizontalAlignment="Center" Height="325" Width="275" Margin="0,0,0,0" VerticalAlignment="Center" Grid.Column="0" ItemsSource="{Binding SomeDrinks}">
<ListBox.ItemTemplate>
<DataTemplate>
<Grid Margin="0,2">
<Grid.ColumnDefinitions>
<ColumnDefinition Width="*" />
<ColumnDefinition Width="*" />
<ColumnDefinition Width="*" />
<ColumnDefinition Width="*" />
</Grid.ColumnDefinitions>
<TextBlock Text="{Binding Type}" Width="80" Margin="0,0,10,0" Grid.Column="0"/>
<TextBlock Text="{Binding Name}" Width="80" Margin="0,0,10,0" Grid.Column="1" HorizontalAlignment="Left"/>
<TextBlock Text="{Binding NumberOfCans}" Width="80" Margin="0,0,10,0" Grid.Column="2" HorizontalAlignment="Left"/>
<Button x:Name="DrinkDeleteButton" Content="Delete" Visibility="{Binding Path=IsUserDefined, Converter={StaticResource BoolToVis}}" Click="CmdDeleteDrink_Clicked" HorizontalAlignment="Left" Grid.Column="3"/>
</Grid>
</DataTemplate>
</ListBox.ItemTemplate>
</ListBox>
<TextBox x:Name="DrinkNameTextBox" Grid.Column="1" HorizontalAlignment="Left" Height="45" Margin="0,0,0,100" TextWrapping="Wrap" Text="Enter Drink Name" VerticalAlignment="Center" Width="240" FontSize="20" VerticalContentAlignment="Center"/>
<TextBox x:Name="NumberCansTextBox" Style="{StaticResource textStyleTextBox}" Grid.Column="1" HorizontalAlignment="Left" Height="45" Margin="0,0,0,150" VerticalAlignment="Bottom" Width="240" FontSize="20" VerticalContentAlignment="Center">
<TextBox.Text>
<Binding Path="NumberOfCans" UpdateSourceTrigger="PropertyChanged" Source="{StaticResource Drink}">
<Binding.ValidationRules>
<local:NumberCansValidationRule Min="0" Max="10"/>
</Binding.ValidationRules>
</Binding>
</TextBox.Text>
</TextBox>
<ComboBox x:Name="DrinkTypeComboBox" Grid.Column="1" HorizontalAlignment="Left" Margin="0,47,0,0" VerticalAlignment="Top" Width="240" Height="45" ItemsSource="{Binding Drinks, Mode=OneWay}" DisplayMemberPath="Type" FontSize="20"/>
<Button x:Name="AddDrinkButton" Content="Add Drink" Grid.Column="1" HorizontalAlignment="Right" Margin="0,0,10,100" VerticalAlignment="Center" Width="100" Height="45" Click="CmdAddDrink_Clicked">
<Button.Style>
<Style TargetType="{x:Type Button}">
<Setter Property="IsEnabled" Value="False"/>
<Style.Triggers>
<MultiDataTrigger>
<MultiDataTrigger.Conditions>
<Condition Binding="{Binding Path=(Validation.HasError), ElementName=NumberCansTextBox}" Value="False"/>
</MultiDataTrigger.Conditions>
<Setter Property="IsEnabled" Value="True"/>
</MultiDataTrigger>
</Style.Triggers>
</Style>
</Button.Style>
</Button>
<Button x:Name="TestButton" Content="Test" IsEnabled="{Binding Path=IsUserDefined, UpdateSourceTrigger=PropertyChanged, Source={StaticResource Drink}, Converter={StaticResource EnableConverter}}" Grid.Column="1" HorizontalAlignment="Right" Margin="0,70,10,0" VerticalAlignment="Center" Width="100" Height="45"/>
</Grid>
Here is my converter:
namespace WpfApp1
{
class EnableConverter : IValueConverter
{
public object Convert(object value, Type targetType, object parameter, CultureInfo culture)
{
bool isenable = false;
bool b = (bool)value;
if (b == true)
{
isenable = true;
}
return isenable;
}
public object ConvertBack(object value, Type targetType, object parameter, CultureInfo culture)
{
throw new NotImplementedException();
}
}
}
This class contains the "IsUserDefined" property that I am binding to:
public class Drinks
{
private string type;
private string name;
private int numCans;
public Drinks() { }
public Drinks(string type, string name, int numCans)
{
this.type = type;
this.name = name;
this.numCans = numCans;
}
public bool IsUserDefined { get; set; }
public string Type
{
get { return type; }
set
{
if (type != value)
{
type = value;
}
}
}
public string Name
{
get { return name; }
set
{
if (name != value)
{
name = value;
}
}
}
public int NumberOfCans
{
get { return numCans; }
set
{
if (numCans != value)
{
numCans = value;
}
}
}
}
