Resizable ComboBox

• Download C# source - 53.24 KB
• Download VB source - 69.21 KB

Introduction

When I create a project for using a DataGrid with ComboBox, I hope to get a resizable ComboBox to set its Height as the Height of DataGrid cell. This is my trial to create a resizable ComboBox ActiveX, now I can change its Height. Some programmers use Form, ListBox, TextBox and Button to create ComboBox, but I am using Panel, ComboBox, TextBox and Button to create my ActiveX.

Background

I am using Panel to hide the upper part of ComboBox and using this Panel as container for TextBox and Button.

About the Project of my ActiveX:

Name of the Project is: MKCombo
Name of UserControl is: KCombo
Name of Panel is: ComboHide
Name of ComboBox is: ComboCtrl
Name of TextBox is: ComboText
Name of Button is: ComboButton

After you expand the files: Combo_C#.zip and Combo_VB.zip, you can open 'SizableCombo' solution to read the code of my ActiveX in the 'MKCombo' project and read the code to test the ActiveX in the 'SizableCombo' project. I try to use 'DataSource' to bind my ActiveX with data but I can't, then I use another idea.

My ActiveX has:

Event: cmbSelectedChanged for SelectedIndexChanged event.
Property: cmbBorderStyle for BorderStyle property.
Property: cmbSelectedIndex for SelectedIndex property.
Property: cmbSelectedItem for SelectedItem property.
Property: cmbText for Text property.
Property: cmbItemsCount for Items.Count property.
Method: cmbAddItem for Items.Add method.
Method: cmbClear for Items.Clear method.

Using the Code

C# code to bind the ActiveX with data:

public void cmbBindData(string cmbSql, OleDbConnection cmbCnn, string cmbField)
{ 
    if (cmbCnn.State == ConnectionState.Open)
        cmbCnn.Close(); 
    cmbCnn.Open(); 
    OleDbCommand cmdReader = new OleDbCommand(cmbSql, cmbCnn);
    OleDbDataReader datRdr = cmdReader.ExecuteReader(); 
    ComboCtrl.Items.Clear(); 
    while (datRdr.Read())
    { 
        ComboCtrl.Items.Add(datRdr[cmbField]); 
    } 
    ComboCtrl.SelectedIndex = 0;
} 

VB code to bind the ActiveX with data:

Public Sub cmbBindData(ByVal cmbSql As String, _
    ByVal cmbCnn As OleDbConnection, ByVal cmbField As String)
    If (cmbCnn.State = ConnectionState.Open) Then cmbCnn.Close()
    cmbCnn.Open()
    Dim cmdReader As OleDbCommand = New OleDbCommand(cmbSql, cmbCnn)
    Dim datRdr As OleDbDataReader = cmdReader.ExecuteReader()
 
    ComboCtrl.Items.Clear()
    While (datRdr.Read())
       ComboCtrl.Items.Add(datRdr(cmbField))
    End While 
   ComboCtrl.SelectedIndex = 0
End Sub

Remark

When executing the test project, please resize any row to see how the ComboBox changes its Height.

Final Words

I hope this article is useful. If you have any ideas, please tell me. Thanks to CodeProject and thanks to all.

Mostafa Kaisoun
m_kaisoun@hotmail.com 

History

• 21^st February, 2011: Initial version