This might be a bug in the WPF Toolkit DataGrid.
In my Windows.Resources I define the following ColumnHeaderStyle:
<Style x:Name="ColumnStyle" x:Key="ColumnHeaderStyle" TargetType="my:DataGridColumnHeader">
<Setter Property="ContentTemplate">
<Setter.Value>
<DataTemplate>
<StackPanel Orientation="Vertical">
<TextBlock Text="{Binding Name}" />
<TextBlock Text="{Binding Data}" />
</StackPanel>
</DataTemplate>
</Setter.Value>
</Setter>
</Style>
Because my columns are generated dynamically, I am defining the columns in code:
private void CreateColumn(Output output, int index)
{
Binding textBinding = new Binding(string.Format("Relationships[{0}].Formula", index));
DataGridTextColumn tc = new DataGridTextColumn();
tc.Binding = textBinding;
dg.Columns.Add(tc);
tc.Header = output;
}
where Output is a simple class with Name and Data (string) properties.
What I observe is that only the Name property (first TextBlock control in the ContentTemplate's StackPanel) is shown. When I drag one of these column headers, I see the entire header (including the Data TextBlock). Only after manually resizing one of the columns are the column headers rendered correctly. Is there a way to get the column headers to show up correctly in code?
Update: as requested, here is the rest of my code for the repro.
public class Input
{
public Input()
{
Relationships = new ObservableCollection<Relationship>();
}
public string Name { get; set; }
public string Data { get; set; }
public ObservableCollection<Relationship> Relationships { get; set; }
}
public class Output
{
public Output() { }
public string Name { get; set; }
public string Data { get; set; }
}
public class Relationship
{
public Relationship() { }
public string Formula { get; set; }
}
Here is the XAML markup:
<Window x:Class="GridTest.Window1"
xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
Title="Window1" Height="300" Width="300" xmlns:my="http://schemas.microsoft.com/wpf/2008/toolkit">
<Window.Resources>
<SolidColorBrush x:Key="RowHeaderIsMouseOverBrush" Color="Red" />
<SolidColorBrush x:Key="RowBackgroundSelectedBrush" Color="Yellow" />
<BooleanToVisibilityConverter x:Key="bool2VisibilityConverter" />
<Style x:Key="RowHeaderGripperStyle" TargetType="{x:Type Thumb}">
<Setter Property="Height" Value="2"/>
<Setter Property="Background" Value="Green"/>
<Setter Property="Cursor" Value="SizeNS"/>
<Setter Property="Template">
<Setter.Value>
<ControlTemplate TargetType="{x:Type Thumb}">
<Border Padding="{TemplateBinding Padding}"
Background="{TemplateBinding Background}"/>
</ControlTemplate>
</Setter.Value>
</Setter>
</Style>
<Style x:Name="ColumnStyle" x:Key="ColumnHeaderStyle" TargetType="my:DataGridColumnHeader">
<Setter Property="ContentTemplate">
<Setter.Value>
<DataTemplate>
<StackPanel Orientation="Vertical">
<TextBlock Text="{Binding Name}" />
<TextBlock Text="{Binding Data}" />
</StackPanel>
</DataTemplate>
</Setter.Value>
</Setter>
</Style>
<!-- from http://www.codeplex.com/wpf/WorkItem/View.aspx?WorkItemId=9193 -->
<Style x:Name="RowHeaderStyle" x:Key="RowHeaderStyle" TargetType="my:DataGridRowHeader">
<Setter Property="Content" Value="{Binding}" />
<Setter Property="ContentTemplate">
<Setter.Value>
<DataTemplate>
<StackPanel Orientation="Horizontal">
<TextBlock Text="{Binding Path=Content.Name, RelativeSource={RelativeSource FindAncestor,AncestorType={x:Type my:DataGridRowHeader}}}"
VerticalAlignment="Center"/>
<TextBlock Padding="5">|</TextBlock>
<TextBlock Text="{Binding Path=Content.Data, RelativeSource={RelativeSource FindAncestor,AncestorType={x:Type my:DataGridRowHeader}}}"
VerticalAlignment="Center"/>
</StackPanel>
</DataTemplate>
</Setter.Value>
</Setter>
</Style>
<DataTemplate x:Key="CellTemplate">
<StackPanel>
<TextBox Text="{Binding Formula, Mode=TwoWay}" />
</StackPanel>
</DataTemplate>
<DataTemplate x:Key="CellEditTemplate">
<StackPanel>
<TextBox Text="{Binding Formula, Mode=TwoWay}" />
</StackPanel>
</DataTemplate>
</Window.Resources>
<Grid>
<my:DataGrid Name="dg"
ColumnHeaderStyle="{StaticResource ColumnHeaderStyle}"
RowHeaderStyle="{StaticResource RowHeaderStyle}"
HeadersVisibility="All" />
</Grid>
</Window>
And finally the code-behind:
/// <summary>
/// Interaction logic for Window1.xaml
/// </summary>
public partial class Window1 : Window
{
public Window1()
{
InitializeComponent();
Inputs = new List<Input>();
Outputs = new List<Output>();
Input i1 = new Input() { Name = "I 1", Data = "data 1" };
Input i2 = new Input() { Name = "I 2", Data = "data 2" };
Inputs.Add(i1); Inputs.Add(i2);
Output o1 = new Output() { Name = "O 1", Data = "data 1" };
Output o2 = new Output() { Name = "O 2", Data = "data 2" };
Output o3 = new Output() { Name = "O 3", Data = "data 3" };
Outputs.Add(o1); Outputs.Add(o2); Outputs.Add(o3);
Relationship r1 = new Relationship() { Formula = "F1" };
Relationship r2 = new Relationship() { Formula = "F2" };
Relationship r3 = new Relationship() { Formula = "F3" };
Relationship r4 = new Relationship() { Formula = "F4" };
i1.Relationships.Add(r1);
i1.Relationships.Add(r2);
i2.Relationships.Add(r3);
i2.Relationships.Add(r4);
CreateColumn(o1, 0);
CreateColumn(o2, 1);
CreateColumn(o3, 2);
dg.Items.Add(i1);
dg.Items.Add(i2);
dg.ColumnWidth = DataGridLength.SizeToHeader;
}
private void CreateColumn(Output output, int index)
{
Binding textBinding = new Binding(string.Format("Relationships[{0}].Formula", index));
DataGridTextColumn tc = new DataGridTextColumn();
tc.Binding = textBinding;
dg.Columns.Add(tc);
tc.Header = output;
}
private List<Output> Outputs { get; set; }
private List<Input> Inputs { get; set; }
}
The issue is fixed if the columns are created in the Loaded event handler, rather than in the constructor of the window.