Customize the header checkbox behavior in GridViewCheckBoxColumn

Environment

Product Version	Product	Author
2019.1.219	RadGridView for WinForms	Dimitar Karamfilov

Description

This article describes how you can change the behavior of the header checkbox in the GridViewCheckBoxColumn. This allows to specify which cell should be checked or perform a completely different action when the checkbox state is changed.

Solution

In this example I am using the value in another cell in order to determine which cells should be changed. I am using the ShouldCheckDataRows property to disable the default behavior. In the HeaderCellToggleStateChanged event handler I am changing the value of the cells that meet specific criteria.

Customize the header checkbox behavior

• C#
• VB.NET

private void RadForm1_Load(object sender, EventArgs e)
{
    var checkBoxColumn = radGridView1.Columns[3] as GridViewCheckBoxColumn;
    checkBoxColumn.EnableHeaderCheckBox = true;
    checkBoxColumn.ShouldCheckDataRows = false;
    checkBoxColumn.ReadOnly = true;
    radGridView1.HeaderCellToggleStateChanged += RadGridView1_HeaderCellToggleStateChanged;
}

private void RadGridView1_HeaderCellToggleStateChanged(object sender, GridViewHeaderCellEventArgs e)
{
    foreach (GridViewDataRowInfo row in radGridView1.Rows)
    {
        var value = (int)row.Cells[0].Value;
        if (value < 50)
        {
            row.Cells[3].Value = !(bool)row.Cells[3].Value;
        }
    }
}

Private Sub RadForm1_Load(ByVal sender As Object, ByVal e As EventArgs)
    Dim checkBoxColumn = TryCast(radGridView1.Columns(3), GridViewCheckBoxColumn)
    checkBoxColumn.EnableHeaderCheckBox = True
    checkBoxColumn.ShouldCheckDataRows = False
    checkBoxColumn.ReadOnly = True
    AddHandler radGridView1.HeaderCellToggleStateChanged, AddressOf RadGridView1_HeaderCellToggleStateChanged
End Sub

Private Sub RadGridView1_HeaderCellToggleStateChanged(ByVal sender As Object, ByVal e As GridViewHeaderCellEventArgs)
    For Each row As GridViewDataRowInfo In radGridView1.Rows
        Dim value = CInt(Math.Truncate(row.Cells(0).Value))
        If value < 50 Then
            row.Cells(3).Value = Not CBool(row.Cells(3).Value)
        End If
    Next row
End Sub