MultiSelectComboBoxColumn Filter

[Martin]

Hello,

i use the "Mutiselect drop down list column" from http://www.telerik.com/support/kb/winforms/gridview/details/mutiselect-drop-down-list-column-in-radgridview
I'm stuck in the implementation of a filter function (Filter must work in combine with other Columns). I found part of codes for custom filter functions and tried to combine them

The basic filter function works already:

using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Linq;
using System.Text;
using System.Windows.Forms;
using Telerik.WinControls.UI;
using Telerik.WinControls;
using Telerik.WinControls.Data;
using System.Diagnostics;

namespace _547099
{
    public partial class Form1 : Form
    {
        public Form1()
        {
            InitializeComponent();

            DataTable t = new DataTable();
            t.Columns.Add("ID", typeof(int));
            t.Columns.Add("Name", typeof(string));
            t.Rows.Add(1, "one");
            t.Rows.Add(2, "two");
            t.Rows.Add(3, "three");
            t.Rows.Add(4, "four");
            t.Rows.Add(5, "five");
            t.Rows.Add(6, "six");
            t.Rows.Add(7, "seven");
            t.Rows.Add(8, "eight");
            t.Rows.Add(9, "nine");
            t.Rows.Add(10, "ten");

            CustomColumn col = new CustomColumn("MutiSelect column");
            col.Name = "Name";
            col.DataSource = t;
            col.DisplayMember = "Name";
            col.ValueMember = "ID";
            FilterDescriptor descriptor = new FilterDescriptor("Name", FilterOperator.Contains, 0);
            //col.AllowFiltering = false;


            radGridView1.Columns.Add(col);

            GridViewTextBoxColumn col2 = new GridViewTextBoxColumn();
            col2.Name = "Test";
            radGridView1.Columns.Add(col2);

            radGridView1.Rows.Add(new object[] { new int[] { 9, 6, 10 }, "ab"});
            radGridView1.Rows.Add(new object[] { new int[] { 5, 1, 3 }, "abcd"});
            radGridView1.Rows.Add(new object[] { new int[] { 8, 7, 1 }, "ef"});
            radGridView1.Rows.Add(new object[] { new int[] { 4, 2, 1 }, "fgh" });

            this.radGridView1.EnableFiltering = true;
            this.radGridView1.ShowHeaderCellButtons = true;
            this.radGridView1.EnableCustomFiltering = true;
            this.radGridView1.CustomFiltering += new GridViewCustomFilteringEventHandler(radGridView1_CustomFiltering);

            this.radGridView1.CellEndEdit += new GridViewCellEventHandler(radGridView1_CellEndEdit);
            this.radGridView1.CellValidating += new CellValidatingEventHandler(radGridView1_CellValidating);
            this.radGridView1.FilterExpressionChanged += radGridView1_FilterExpressionChanged;

        }

        void radGridView1_FilterExpressionChanged(object sender, FilterExpressionChangedEventArgs e)
        {
            Debug.WriteLine("Filter geändert: " + e.FilterExpression);
        }

        void radGridView1_CellValidating(object sender, CellValidatingEventArgs e)
        {
            if (radGridView1.ActiveEditor == null ||!( e.Row is GridViewFilteringRowInfo)) return;

            if (e.Column.GetDefaultEditorType() == typeof(CustomDropDownListEditor))
            {
                filterValues.Clear();
                foreach (CustomListDataItem item in ((CustomEditorElement)(((CustomDropDownListEditor)(this.radGridView1.ActiveEditor)).EditorElement)).Items)
                {
                    if (item.Selected)
                    {
                        filterValues.Add((int)item.Value);
                    }
                }
            }
        }

        List<int> filterValues = new List<int>();
        void radGridView1_CellEndEdit(object sender, GridViewCellEventArgs e)
        {
            Debug.WriteLine("Refresh");
            this.radGridView1.MasterTemplate.Refresh();
        }

        private void radGridView1_CustomFiltering(object sender, GridViewCustomFilteringEventArgs e)
        {
            if (filterValues.Count == 0)
            {
                Debug.WriteLine("FilterVal 0");
                int fdi = radGridView1.FilterDescriptors.IndexOf("Name");
                if (fdi != -1)
                {
                    radGridView1.FilterDescriptors.RemoveAt(fdi);
                }
            }

            if (radGridView1.FilterDescriptors.Count == 0)
            {
                return;
            }

            if (filterValues.Count > 0)
            {
                bool shouldVisible = false;
                foreach (int cellValue in ((int[])e.Row.Cells["Name"].Value))
                {
                    foreach (int j in filterValues)
                    {
                        if (cellValue == j)
                        {
                            shouldVisible = true;
                            break;
                        }
                    }
                }
                e.Visible = shouldVisible;
            }

            if (e.Visible) e.Handled = false;
        }
    }
}

So i can filter in custom column "Name" (MultiSelectDropdownColumn) and also in Column2 "Test" (TextboxColumn). good so far

After i filtered something in Column "Test" followed by clear this filter, i try to filter in custom column "Name" again but this time the filter don't work (all Rows will hidden or only one matching row will shown).

Does anyone have any idea where the fault lies?

[Stefan]

Hi Martin,

Thank you for writing.

I tried to run your solution, but I was unable to get it working. Instead, I have created a simpler solution, where the column will not be a combo column, instead, it will use a text box column holding a string with the multiple selected values. Once an editor is requested, we will provide a drop down editor and we will select the items needed. This approach seems to work correctly, including filtering by multiple columns. Please give it a try and let me know how does it work for you.

Regards,
Stefan
Telerik

 

 

[Martin]

Hello Stefan,

many thanks for your effort.

That would work for me too, with a small extension:
If i filter with only one value, the default "contains" filter works well, but for my project i need the possibility to filter with a few values by "or condition":
For example: i checked in filter "one" and "two" -> rows must been shown with containing "one" OR "two" value
So only one of the values ​​must be present in a row.

Regards,
Martin

[Stefan]

Hello,

To do that, you can cancel the default filtering when the grid attempts to filter by the Name column and use a CompositeFilterDescriptor to handle it on your own. Attached you can find a sample of this.

If this does not work for you, you can try the custom filtering abilities of the control: http://www.telerik.com/help/winforms/gridview-filtering-custom-filtering.html.

I hope I was able to help.

Regards,
Stefan
Telerik

 

 

[Martin]

Many thanks it works great.

Regards
Martin