Checkboxcolumn in a grid (only one must be checked)

[Filleau]

Hi

I have a RadGrid with 3 columns.

Column 1 is a GridViewCheckBoxColumns named "ColA"
Column 2 is a GridViewTextBoxColumn named "ColB"
Column 3 is a GridViewCheckBoxColumn named "ColC"

On the third Column only, I want that only one row can be checked.
So if user click on a CheckBox in Columns 3, all others CheckBox for this column must be unchecked.

How to do this ?

Thanks

[Emanuel Varga]

Hello Filleau,

It's a very rough example but it should do what you want:

using System.Collections.Generic;
using System.Linq;
using System.Windows.Forms;
using Telerik.WinControls.UI;

public partial class Form1 : Form
{
    private RadGridView radGridView1;

    public Form1()
    {
        InitializeComponent();
        this.Controls.Add(radGridView1 = new RadGridView());
        radGridView1.Dock = DockStyle.Fill;
        radGridView1.AutoSizeColumnsMode = GridViewAutoSizeColumnsMode.Fill;

        var persons = new List<Person>();
        for (int i = 0; i < 10; i++)
        {
            persons.Add(new Person { ID = i, Name = "Person " + i, Active = i % 2 == 0, Representative = false });
        }

        radGridView1.DataSource = persons;
        radGridView1.ValueChanging += new ValueChangingEventHandler(radGridView1_ValueChanging);
    }

    void radGridView1_ValueChanging(object sender, ValueChangingEventArgs e)
    {
        if (radGridView1.CurrentColumn.FieldName == "Representative")
        {
            foreach (var row in radGridView1.Rows.Where(r =>
                r.DataBoundItem != null && r.Cells["Representative"].Value != null && (bool)r.Cells["Representative"].Value &&
                e.NewValue != null && ((bool)e.NewValue) != false))
            {
                row.Cells["Representative"].Value = false;
            }
        }
    }
}

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

    public string Name { get; set; }

    public bool Active { get; set; }

    public bool Representative { get; set; }
}

Hope this helps, if you have any other questions or comments, please let me know,

Best Regards,
Emanuel Varga

Telerik WinForms MVP

[Filleau]

Thanks

But because I'm working with VB, I used the Telerik Converter to try your solution.

But I have a problem with this line

radGridView1.ValueChanging += new ValueChangingEventHandler(radGridView1_ValueChanging);

in VB : radGridView1.ValueChanging += New ValueChangingEventHandler(radGridView1_ValueChanging)


I don't know where to put it.... Everywhere VS Editor mark it as error

It's seem I don't have or don't found the Sub NEW()




[Emanuel Varga]

Hello Fileau,

Those are the AddHandler and RemoveHandler , please change those to this:

AddHandler radGridView1.ValueChanging, AddressOf radGridView1_ValueChanging

You should put it in the constructor, or if you prefer to do this from the designer, go to the grid, events, and register for the ValueChanging event from there.

Hope this helps, if you have any other questions or comments, please let me know,

Best Regards,
Emanuel Varga

Telerik WinForms MVP

[Filleau]

Hey thanks  !

It was so simple.

I just resume in :

 

Private Sub RadGridView1_CellValueChanged(ByVal sender As System.Object, ByVal e As Telerik.WinControls.UI.GridViewCellEventArgs) Handles RadGridView1.CellValueChanged
 If RadGridView1.CurrentColumn.Name = "ColC" Then
  For Each row As GridViewRowInfo In RadGridView1.Rows

     row.Cells("ColC").Value = False

  Next
 End If

End Sub

[Filleau]

Hi

I have one more problem with my code.

On my grid everything seem to be good. I can have only one checkbox checked.

But after If I put a RadButton with a code like this :

For Each row As GridViewRowInfo In RadGridView1.Rows

    If row.Cells("ColC").Value = True Then MsgBox("Hello World !")
 Next

The MsgBox is never Display.
I have on checkbox checked on the screen but the value is False !

Thanks

[Emanuel Varga]

Hello again,

Try it like this:

Private Sub button_Click(sender As Object, e As System.EventArgs)
    For Each row As var In Me.radGridView1.Rows
        If row.Cells("Representative").Value IsNot Nothing AndAlso CBool(row.Cells("Representative").Value) Then
            MessageBox.Show("Row " + row.Index + " is checked!")
        End If
    Next
End Sub

Hope this helps, if you have any other questions or comments, please let me know,

Best Regards,
Emanuel Varga

Telerik WinForms MVP

[Filleau]

Sorry but no success with it.

Private Sub RadGridView1_CellValueChanged(ByVal sender As System.Object,
ByVal e As Telerik.WinControls.UI.GridViewCellEventArgs) Handles
RadGridView1.CellValueChanged
  If RadGridView1.CurrentColumn.Name = "Master" Then
      For Each row As GridViewRowInfo In RadGridView1.Rows
            row.Cells("Master").Value = False
      Next
  End If
End Sub

Private Sub RadButton8_Click(ByVal sender As System.Object, ByVal e As
System.EventArgs) Handles RadButton8.Click
  For Each row As GridViewRowInfo In RadGridView1.Rows
       If Not row.Cells("Master").Value Is Nothing AndAlso CBool(row.Cells("Master").Value) Then
          MessageBox.Show("Row " + row.Index + " is checked!")
       End If
  Next
End Sub

[Emanuel Varga]

Hello again,

Sorry, i cannot reproduce this problem, but there is one thing that you have changed from my example: The ValueChanging event with the CellValueChanged, basically you are calcelling the selection there, because the ValueChanging event fires before the value has been changed, so I could easily change all of the row's selection state to false, but because you are using the CellValueChanged event you have to ignore the CurrentRow's state.

Hope you understood, with my suggestion here is a full example:

Imports System.Collections.Generic
Imports System.Linq
Imports System.Windows.Forms
Imports Telerik.WinControls.UI

Partial Public Class Form1
    Inherits Form
    Private radGridView1 As RadGridView

    Public Sub New()
        InitializeComponent()
        Me.Controls.Add(InlineAssignHelper(radGridView1, New RadGridView()))
        radGridView1.Dock = DockStyle.Fill
        radGridView1.AutoSizeColumnsMode = GridViewAutoSizeColumnsMode.Fill

        Dim persons = New List(Of Person)()
        For i As Integer = 0 To 9
            persons.Add(New Person() With { _
             .ID = i, _
             .Name = "Person " + i.ToString, _
             .Active = i Mod 2 = 0, _
             .Representative = False _
            })
        Next

        radGridView1.DataSource = persons
        AddHandler radGridView1.ValueChanging, AddressOf radGridView1_ValueChanging

        Dim button As New RadButton
        button.Text = "Click me!"
        AddHandler button.Click, AddressOf Button_Click
        button.Dock = DockStyle.Bottom
        Controls.Add(button)

    End Sub

    Private Sub radGridView1_ValueChanging(ByVal sender As Object, ByVal e As ValueChangingEventArgs)
        If radGridView1.CurrentColumn.FieldName = "Representative" Then
            For Each row As GridViewDataRowInfo In radGridView1.Rows.Where(Function(r) r.DataBoundItem IsNot Nothing AndAlso r.Cells("Representative").Value IsNot Nothing AndAlso CBool(r.Cells("Representative").Value) AndAlso e.NewValue IsNot Nothing AndAlso CBool(e.NewValue) <> False)
                row.Cells("Representative").Value = False
            Next
        End If
    End Sub
    Private Shared Function InlineAssignHelper(Of T)(ByRef target As T, ByVal value As T) As T
        target = value
        Return value
    End Function

    Private Sub Button_Click(ByVal sender As System.Object, ByVal e As System.EventArgs)
        For Each row As GridViewRowInfo In radGridView1.Rows
            If Not row.Cells("Representative").Value Is Nothing AndAlso CBool(row.Cells("Representative").Value) Then
                MessageBox.Show("Row " + row.Index.ToString + " is checked!")
            End If
        Next
    End Sub


End Class

Public Class Person
    Public Property ID() As Integer
        Get
            Return m_ID
        End Get
        Set(ByVal value As Integer)
            m_ID = Value
        End Set
    End Property
    Private m_ID As Integer

    Public Property Name() As String
        Get
            Return m_Name
        End Get
        Set(ByVal value As String)
            m_Name = Value
        End Set
    End Property
    Private m_Name As String

    Public Property Active() As Boolean
        Get
            Return m_Active
        End Get
        Set(ByVal value As Boolean)
            m_Active = Value
        End Set
    End Property
    Private m_Active As Boolean

    Public Property Representative() As Boolean
        Get
            Return m_Representative
        End Get
        Set(ByVal value As Boolean)
            m_Representative = Value
        End Set
    End Property
    Private m_Representative As Boolean
End Class

Hope this helps, if you have any other questions or comments, please let me know,

Best Regards,
Emanuel Varga

Telerik WinForms MVP

[Filleau]

This is it !

Big Thank.


Private Sub RadGridView1_ValueChanging(ByVal sender As System.Object, ByVal e As Telerik.WinControls.UI.ValueChangingEventArgs) Handles RadGridView1.ValueChanging
If RadGridView1.CurrentColumn.Name = "Master" And TypeOf (e.NewValue) Is Boolean Then

   For Each row As GridViewDataRowInfo In RadGridView1.Rows

       If (row.Cells("Master").Value IsNot Nothing AndAlso CBool(row.Cells("Master").Value) AndAlso e.NewValue IsNot Nothing AndAlso CBool(e.NewValue) <> False) Then
          row.Cells("Master").Value = False

       End If

     Next
   End If

End Sub

I made some minors changes because at the beginning I have some problem with your converter result, and also, but I don't know why sometime I got a exeption because a string value (from another column !)... That's why I test typeof(e.newValue)