Disable filtering as you type

[goran]

Hi,

i want to disable filtering as you type in GridView and change it to apply filter only when you leave filter cell.

Had no success with this so far. Can someone help me ?

 

Thanks,

Goran.

[Hristo]

Hi Goran,

Thank you for writing.

RadGridView exposes a FilterChanging event which you can handle depending on your business logic. In order to disable the filtering while typing in the editor, you would need to keep track of the old and new filter values. The filter descriptor needs to be added just before the cell ends editing. Please check my code snippet below: 

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

        this.radGridView1.DataSource = this.GetData();

        this.radGridView1.AutoSizeColumnsMode = Telerik.WinControls.UI.GridViewAutoSizeColumnsMode.Fill;
        this.radGridView1.EnableFiltering = true;

        this.radGridView1.FilterChanging += radGridView1_FilterChanging;

        this.radGridView1.CellBeginEdit += radGridView1_CellBeginEdit;
        this.radGridView1.CellEndEdit += radGridView1_CellEndEdit;
    }

    private void radGridView1_CellEndEdit(object sender, Telerik.WinControls.UI.GridViewCellEventArgs e)
    {
        if (e.Row is GridViewFilteringRowInfo)
        {
            oldValue = null;
        }
    }

    bool shouldCancel;
    private void radGridView1_CellBeginEdit(object sender, Telerik.WinControls.UI.GridViewCellCancelEventArgs e)
    {
        if (e.Row is GridViewFilteringRowInfo)
        {
            ((GridViewDataColumn)e.Column).FilterDescriptor = null;
        }
    }

    object oldValue;
    private void radGridView1_FilterChanging(object sender, Telerik.WinControls.UI.GridViewCollectionChangingEventArgs e)
    {
        if ( oldValue != e.NewValue)
        {
            e.Cancel = true;
        }

        oldValue = e.NewValue;

    }

    private DataTable GetData()
    {
        DataTable dt = new DataTable();

        dt.Columns.Add("Id", typeof(int));
        dt.Columns.Add("Name", typeof(string));
        dt.Columns.Add("Date", typeof(DateTime));
        dt.Columns.Add("Bool", typeof(bool));
        dt.Columns.Add("Description", typeof(string));

        for (int i = 0; i < 100; i++)
        {
            dt.Rows.Add(i, "Name " + i, DateTime.Now.AddDays(i), i % 2 == 0, "Description " + i);
        }

        return dt;
    }
}

I hope this helps. Should you have further questions please do not hesitate to write back.

Regards,
Hristo Merdjanov
Telerik

[goran]

I just want to change BeginEdit function not to clear filter when you enter cell.

So i wrote like this.

private void gridClients_CellBeginEdit(object sender, GridViewCellCancelEventArgs e)
        {
            if (e.Row is GridViewFilteringRowInfo)
            {
                if (this.gridClients.CurrentCell.Value != null)
                    ((GridViewDataColumn)e.Column).FilterDescriptor.Value = this.gridClients.CurrentCell.Value;
                else
                    ((GridViewDataColumn)e.Column).FilterDescriptor = null;
            }
        }

 

It works fine until i enter cell again and delete content of cell.

Then ((GridViewDataColumn)e.Column).FilterDescriptor became NULL and start crashing. When i try to set column FilterDescriptor again from code it wont accept changes ?

FilterDescriptor descriptor = CreateNewFilterDescriptor(this.gridPersons.CurrentCell.Value, (GridViewDataColumn)e.Column);

//dont work
((GridViewDataColumn)e.Column).FilterDescriptor = descriptor;
//dont work either
//this.gridPersons.FilterDescriptors.Add(descriptor);

 

[Hristo]

Hello Goran,

Thank you for writing.

I am not able to observe the exception on my end. I have modified my project to suggest a slightly different approach and not omitting the existing filter when a cell is about to be edited.

I hope this helps. Please let me know if you need further assistance.

Regards,
Hristo Merdjanov
Telerik