EnableHeaderCheckBox

[Claude]

I wish to use the EnableHeaderCheckBox in my grid view but cancel its action under certain conditions (should not select/unselect all if a custom condition is true).  How can I do that?
In the HeaderCellToggleStateChanged, there is no Cancel action in the GridViewHeaderCellEventArgs.

[Hristo]

Hello Claude,

Thank you for writing.

You can reach this kind of behavior by using the Enabled property of the CheckBox object of the GridCheckBoxHeaderCellElement:

public partial class Form1 : Form
{
    public Form1()
    {
        InitializeComponent();
    }

    bool flag = false;
    void radGridView1_ViewCellFormatting(object sender, CellFormattingEventArgs e)
    {
        GridCheckBoxHeaderCellElement headerCell = e.CellElement as GridCheckBoxHeaderCellElement;
        if (headerCell != null)
        {
            headerCell.CheckBox.Enabled = flag;
        }
    }

    private void Form1_Load(object sender, EventArgs e)
    {
        this.productsTableAdapter.Fill(this.nwindDataSet.Products);

        var checkboxColumn = this.radGridView1.Columns["YourCheckBoxColumn"] as GridViewCheckBoxColumn;
        checkboxColumn.EnableHeaderCheckBox = true;

        radGridView1.ViewCellFormatting += radGridView1_ViewCellFormatting;
    }

    private void radButton1_Click(object sender, EventArgs e)
    {
        flag = !flag;
        radGridView1.MasterView.TableHeaderRow.InvalidateRow();

        radButton1.Text = flag.ToString();
    }
}

I hope that this information is useful. Should you have further questions please do not hesitate to write back.

Regards,
Hristo
Telerik