WinForms combobox with multiple columns (C#)?

Question

I am using currently the following code to populate a combobox:

combobox.DataSource = datatable;
combobox.DisplayMember = \"Auftragsnummer\";
combobox.ValueM         


        

Answer 1

The full C# solution I provided for a Multicolumn Combo Box caused a problem when debugging in the app that used it. The problem was with the line "DateTime dt = DateTime.Parse(strColumnText);" in the method "IsDate" here is a new version of the method that uses DateTimeTryparse" instead: I have replaced the faulty version in the original. (N B For all its faults, it works!) cheers, Bruce Caldwell

     private bool IsDate(string strColumnText)
    {
        DateTime dateValue;

        if (DateTime.TryParse(strColumnText, out dateValue))
        {
            return true;
        }
        else
        {
            return false;
        }
    } // end sub

Answer 2

The MultiColumn ComboBox Control combines the Text Box control to edit and the Grid View in the drop down list to display data.

Answer 3

You can add to your dataset a dummy column (Description) and use that as DisplayMember in the combo box databinding.

SELECT Users.*, Surname+' '+Name+' - '+UserRole AS Description FROM Users

ComboBox.DataBindings.Add(new Binding("SelectedValue", bs, "ID"));
ComboBox.DataSource = ds.Tables["Users"];
ComboBox.DisplayMember = "Description";
ComboBox.ValueMember = "ID";

Simple and works.

Answer 4

There's an article on MSDN describing how a Multicolumn ComboBox can be created.

How to create a multiple-column drop-down list for a combo box in Windows Forms

http://support.microsoft.com/kb/982498

---

Source code from the download for VB from the above Microsoft Link, that can be easily adapted to work with a ListBox as well as a ComboBox:

'************************************* Module Header **************************************'
' Module Name:  MainForm.vb
' Project:      VBWinFormMultipleColumnComboBox
' Copyright (c) Microsoft Corporation.
' 
' 
' This sample demonstrates how to display multiple columns of data in the dropdown of a ComboBox.
' 
' This source is subject to the Microsoft Public License.
' See http://www.microsoft.com/opensource/licenses.mspx#Ms-PL.
' All other rights reserved.
' 
' THIS CODE AND INFORMATION IS PROVIDED "AS IS" WITHOUT WARRANTY OF ANY KIND,
' EITHER EXPRESSED OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE IMPLIED
' WARRANTIES OF MERCHANTABILITY AND/OR FITNESS FOR A PARTICULAR PURPOSE.
'******************************************************************************************'

Imports System
Imports System.Collections.Generic
Imports System.ComponentModel
Imports System.Data
Imports System.Drawing
Imports System.Linq
Imports System.Text
Imports System.Windows.Forms
Imports System.Drawing.Drawing2D

Public Class MainForm

    Private Sub MainForm_Load(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles MyBase.Load
        Dim dtTest As DataTable = New DataTable()
        dtTest.Columns.Add("ID", GetType(Integer))
        dtTest.Columns.Add("Name", GetType(String))

        dtTest.Rows.Add(1, "John")
        dtTest.Rows.Add(2, "Amy")
        dtTest.Rows.Add(3, "Tony")
        dtTest.Rows.Add(4, "Bruce")
        dtTest.Rows.Add(5, "Allen")

        ' Bind the ComboBox to the DataTable
        Me.comboBox1.DataSource = dtTest
        Me.comboBox1.DisplayMember = "Name"
        Me.comboBox1.ValueMember = "ID"

        ' Enable the owner draw on the ComboBox.
        Me.comboBox1.DrawMode = DrawMode.OwnerDrawFixed
        ' Handle the DrawItem event to draw the items.
    End Sub

    Private Sub comboBox1_DrawItem(ByVal sender As System.Object, _
                                   ByVal e As System.Windows.Forms.DrawItemEventArgs) _
                                   Handles comboBox1.DrawItem
        ' Draw the default background
        e.DrawBackground()

        ' The ComboBox is bound to a DataTable,
        ' so the items are DataRowView objects.
        Dim drv As DataRowView = CType(comboBox1.Items(e.Index), DataRowView)

        ' Retrieve the value of each column.
        Dim id As Integer = drv("ID").ToString()
        Dim name As String = drv("Name").ToString()

        ' Get the bounds for the first column
        Dim r1 As Rectangle = e.Bounds
        r1.Width = r1.Width / 2

        ' Draw the text on the first column
        Using sb As SolidBrush = New SolidBrush(e.ForeColor)
            e.Graphics.DrawString(id, e.Font, sb, r1)
        End Using

        ' Draw a line to isolate the columns 
        Using p As Pen = New Pen(Color.Black)
            e.Graphics.DrawLine(p, r1.Right, 0, r1.Right, r1.Bottom)
        End Using

        ' Get the bounds for the second column
        Dim r2 As Rectangle = e.Bounds
        r2.X = e.Bounds.Width / 2
        r2.Width = r2.Width / 2

        ' Draw the text on the second column
        Using sb As SolidBrush = New SolidBrush(e.ForeColor)
            e.Graphics.DrawString(name, e.Font, sb, r2)
        End Using
    End Sub
End Class

Answer 5

You can't have a multiple column combo-box.

Would you not be better off using a DataGridView instead