WPF Datagrid - 1st Row show checkbox, 2nd Row Hide Checkbox,...

[Mathias123]

hello! Its me again. I hope somebody can help me!

I don't know if it is possible but i hope so...

i have a datagrid with 2 Columns:

1 Column is a checkbox (template)

<DataGridTemplateColumn Header="geprüft">
    <DataGridTemplateColumn.CellTemplate>
        <DataTemplate>
            <CheckBox Name="chk" Content="{Binding Path=geprüft}" IsChecked="False" IsThreeState="False"/>
        </DataTemplate>
    </DataGridTemplateColumn.CellTemplate>
</DataGridTemplateColumn>

and the last Column is a textbox binding with status

<DataGridTextColumn IsReadOnly="True" Width="auto" Header="status" Binding="{Binding Status}">

now, i only want to show the checkbox if status = 4... so in row1 = show, row2 = hide etc...

is it possible?

and how can i make an event on the checkbox (to save in db if checkbox is checked)

if i make an event:

Private Sub chk_Click(ByVal sender As System.Object, ByVal e As System.Windows.RoutedEventArgs) Handles chk.Click
End Sub

I get an error:
Error Handles clause requires a WithEvents variable defined in the containing type or one of its base types.


hope somebody can help me!

Nice Greets,
Mathias

[Frinavale]

Hi Mathias,

Have you ever used converters before?
Create a class that implements the IValueConverter Interface so that you can bind your IsChecked property to the Status property. The converter will convert the 3, or 4 into a true or false value so that the IsChecked property will work.

-Frinny

[Mathias123]

Hello Frinny,
Thank you for your response! i try to do that... and hope it works.

But i think you don't understand what i need. (because my english is not so good)


1) I only want to see the checkbox when status = 4
If status = 3 or status = 2 or status = 1 then Hide the checkbox in the Row. (only visible on status = 4)

2) If i checked the checkbox in the row with status 4 i want to make an event in the Database. The Status should get the value 5 (Status 5 = Finished)


so is in this case the IValueConverter Interface the best solution?

nice Greets,
Mathias

[Mathias123]

ok now i have a solution for the checkbox to save something in database... i only add Click="CheckBox _Click"

Code to go in a sub :)

 
<DataGridTemplateColumn Header="geprüft"> 
    <DataGridTemplateColumn.CellTemplate> 
        <DataTemplate> 
            <CheckBox Name="chk" Content="{Binding Path=geprüft}" IsChecked="False" IsThreeState="False" Click="CheckBox_Click"/> 
        </DataTemplate> 
    </DataGridTemplateColumn.CellTemplate> 
</DataGridTemplateColumn>

But i have no solution for the first problem (checkbox visible or hidden for each rows)


Good Night, Good Fight!


Nice Greets,
Mathias

[Frinavale]

You can get around this without using converters than...just use triggers like before but apply it to the CheckBox:

<DataGridTemplateColumn>
    <DataGridTemplateColumn.CellTemplate>
        <DataTemplate>
            <CheckBox Name="chk" Content="{Binding Path=geprüft}" IsThreeState="False" Visibility="Collapsed">
                <CheckBox.Style>
                    <Style TargetType="CheckBox">
                        <Style.Triggers>
                            <DataTrigger Binding="{Binding Path=Status}" Value="4">
                                <Setter Property="Visibility" Value="Visible" />
                            </DataTrigger>
                        </Style.Triggers>
                    </Style>
                </CheckBox.Style>
            </CheckBox>
        </DataTemplate>
    </DataGridTemplateColumn.CellTemplate>
</DataGridTemplateColumn>

It seems that you have solved your second part of the question.

-Frinny

[Frinavale]

If you weren't using triggers, and you wanted to try a converter you would do the following.

You would create a class that implements the IValueConverter interface. The purpose of this class would be to return the visibility (collapsed or visible) depending on the Status value. The convert back method would set the status to 5...

I'm just not 100% sure if it would work because I can't really try it....

But your class would look something like this:
(VB.NET)

Public Class StatusVisibilityConverter
    Implements IValueConverter

    Public Function Convert(value As Object, targetType As System.Type, parameter As Object, culture As System.Globalization.CultureInfo) As Object Implements System.Windows.Data.IValueConverter.Convert
        Dim is4Status As Boolean = CType(value, Integer)

        If is4Status = 4 Then
            Return Visibility.Visible
        End If

        Return Visibility.Collapsed
    End Function

    Public Function ConvertBack(value As Object, targetType As System.Type, parameter As Object, culture As System.Globalization.CultureInfo) As Object Implements System.Windows.Data.IValueConverter.ConvertBack
        Throw New NotImplementedException
        'In here you would have to try converting back somehow...I'm just not sure how
    End Function
End Class

(C#)

public class StatusVisibilityConverter : IValueConverter
{

	public object Convert(object value, System.Type targetType, object parameter, System.Globalization.CultureInfo culture)
	{
		bool is4Status = Convert.ToInt32(value);

		if (is4Status == 4) {
			return Visibility.Visible;
		}

		return Visibility.Collapsed;
	}

	public object ConvertBack(object value, System.Type targetType, object parameter, System.Globalization.CultureInfo culture)
	{
		throw new NotImplementedException();
		//In here you would have to try converting back somehow...I'm just not sure how
	}
}

Add your project's namespace to your window/user control/page:

<Window x:Class="Window1"
        xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
        xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
        xmlns:myProject="clr-namespace:MyProjectNamespace"
        Title="Window1" Height="760" Width="800"
        Background="White">

Add your visibility converter as a resource to the Window/User Control/Page...or even as a resource to your grid...so that you can use it:

<Window.Resources>
    <myProject:StatusVisibilityConverter x:Key="StatusVisibilityConverter" />
</Window.Resources>

Then change the XAML code for your CheckBox so that it's Visibility property is bound to your Status property and uses your new converter:

<DataGridTemplateColumn>
    <DataGridTemplateColumn.CellTemplate>
        <DataTemplate>
            <CheckBox Name="chk" Content="{Binding Path=geprüft}" IsChecked="{Binding Path=Status}" IsThreeState="False"
                      Visibility="{Binding Path=Status, Converter={StaticResource StatusVisibilityConverter}}" />
        </DataTemplate>
    </DataGridTemplateColumn.CellTemplate>
</DataGridTemplateColumn>

-Frinny

[Mathias123]

Hi!

I try the first post (because I'm new in WPF) but it doesn't work... the property

<Setter Property="Visibility" Value="Visible" />

doesn't work?!

i try another Property

<Setter Property="IsEnabled" Value="false"/>

and it works... All other Properties work, but i don't know why the Property "Visibility " doesn't work...

[Frinavale]

It would help if you posted the whole style because it worked when I tried it before posting...

-Frinny

[Mathias123]

now i tried your second post and it work!

thank you for your help!!!!!

[Frinavale]

I'm glad it works.

Just make sure you implement the "convert back" method so that it works properly.

-Frinny