WPF databound Datagrid change horizontal column orientation depending on data type

Question

I´m trying to change the horizontal column alignment of a databound DataGrid depending on the data type (e.g. Int32, float,..).

After searching the web for a simple example for ages I have learned, that DataTriggers via xaml should be the right option to do that. Is that right? If so, how would I implement the trigger?

I am quite new to WPF and have been using WindowsForms in the past. It can´t be that difficult to change the column orientation dependent on the data type? Any help is appreciated!

Answer 1

Ok, I´ve solved this from the code behind now. Maybe someone could give me a hint how I could solve this more elegantly using XAML? I´ve been searching the web for hours to find an example thats not too hard for someone who´s new to WPF and just didn´t find anything a was able to implement successfully.

Ok, here´s the code: Having a DataTable as DataSource I add the following:

foreach (DataColumn cc in table.Columns)
{
    Type type = cc.DataType;

    Style alignStyle = new Style(typeof(Microsoft.Windows.Controls.DataGridCell));                            
    alignStyle.Setters.Add(new Setter(Microsoft.Windows.Controls.DataGridCell.VerticalAlignmentProperty, VerticalAlignment.Center));

    var column = new Microsoft.Windows.Controls.DataGridTextColumn
    {
        Header = cc.ColumnName,
        Binding = new Binding(cc.ColumnName)
    };

    if(type.Name=="Int32"){
        alignStyle.Setters.Add(new Setter(TextBlock.TextAlignmentProperty, TextAlignment.Right));
        column.Foreground = Brushes.Red;
        column.CellStyle = alignStyle;
    }
    else if (type.Name == "DateTime")
    {
        alignStyle.Setters.Add(new Setter(TextBlock.TextAlignmentProperty, TextAlignment.Center));
        column.Foreground = Brushes.Green;
        column.Binding.StringFormat = "{0:dd.MM.yyyy}";
        column.CellStyle = alignStyle;
    }
    else if (type.Name == "String")
    {
        alignStyle.Setters.Add(new Setter(TextBlock.TextAlignmentProperty, TextAlignment.Left));
        column.Foreground = Brushes.Blue;
        column.CellStyle = alignStyle;
    }
    else if (type.Name == "Double")
    {
        alignStyle.Setters.Add(new Setter(TextBlock.TextAlignmentProperty, TextAlignment.Right));
        column.Foreground = Brushes.Brown;
        column.Binding.StringFormat = "{0:F3}";
        column.CellStyle = alignStyle;
    }

    grids.Columns.Add(column);
}

Answer 2

This may help - Different views / data template based on member variable

Another option is to use DataTemplate selector. Just check this tutorial: http://tech.pro/tutorial/807/wpf-tutorial-how-to-use-a-datatemplateselector

Answer 3

You can handle AutoGeneratingColumn event.

In your xaml add :

<DataGrid ItemsSource="{Binding}" AutoGenerateColumns="True" 
          AutoGeneratingColumn="DataGrid_OnAutoGeneratingColumn"></DataGrid>

In code-behind:

private void DataGrid_OnAutoGeneratingColumn(object sender, DataGridAutoGeneratingColumnEventArgs e)
{
   if (e.PropertyType == typeof (Int32))
   {
       if (e.Column != null)
       {
          var dgct = new DataGridTemplateColumn();
          var cName = e.Column.Header as string;
          var b = new Binding(cName);

          var sfactory = new FrameworkElementFactory(typeof(TextBlock));
          sfactory.SetValue(TextBlock.TextProperty, b);
          sfactory.SetValue(TextBlock.TextAlignmentProperty, TextAlignment.Right);
          var cellTemplate = new DataTemplate();
          cellTemplate.VisualTree = sfactory;
          dgct.CellTemplate = cellTemplate;

          dgct.Header = cName;
          dgct.SortMemberPath = cName;

          e.Column = dgct;
       }
   }

   ... *and so on for all your data types*

}

You can check these links:

http://msdn.microsoft.com/en-us/library/cc903950(v=vs.95).aspx http://mareinsula.wordpress.com/2011/06/06/tips-on-wpf-autogeneratinged-datagrid/