WPF DataGrid -> Icon Shown For CellEditingTemplate

Question

When you use a combo box in the CellEditingTemplate a drop down arrow is shown on the right hand side of the cell. When you use a date picker a small calender is shown on the right hand side of the cell.

When creating a CellEditingTemplate how do you control what is shown in this area? If you use a custom control and want to show a icon in this area how would this be done?

Answer 1

You should add this icon in your custom user control.

Example:

Let's say that we have simple class Person:

class Person
{
    public int ID { get; set; }
    public string Name { get; set; }
}

and we want to create custom control to edit person name.

1) We must add icon to our app as resource (Build Action = Resource).

In my example I created folder Images and put there icon "user.png".

2) In the next step we create custom control "NameUserControl":

<UserControl x:Class="WpfApplicationDataGrid.NameUserControl"
             xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
             xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
             xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006" 
             xmlns:d="http://schemas.microsoft.com/expression/blend/2008" 
             mc:Ignorable="d" 
             d:DesignHeight="300" d:DesignWidth="300">
    <Grid>
        <Grid.ColumnDefinitions>
            <ColumnDefinition Width="*" />
            <ColumnDefinition Width="30" />
        </Grid.ColumnDefinitions>      

        <TextBox Text="{Binding Path=Name}" />
        <Image Source="/Images/user.png" Grid.Column="1" />
    </Grid>
</UserControl>

3) Now we can using new custom user control in CellEditingTemplate:

<DataGrid ItemsSource="{Binding}" AutoGenerateColumns="False">
    <DataGrid.Columns>
        <DataGridTextColumn Header="ID" Binding="{Binding ID}" />
        <DataGridTemplateColumn Header="Name">
            <DataGridTemplateColumn.CellTemplate>
                <DataTemplate>
                    <TextBlock Text="{Binding Name}" />
                </DataTemplate>
            </DataGridTemplateColumn.CellTemplate>
            <DataGridTemplateColumn.CellEditingTemplate>
                <DataTemplate>
                    <local:NameUserControl />
                </DataTemplate>
            </DataGridTemplateColumn.CellEditingTemplate>
        </DataGridTemplateColumn>
    </DataGrid.Columns>
</DataGrid>

Result: