Auto Complete ComboBox – VB.NET Windows Forms

Solomon — Tue, 24 Feb 2009 04:40:15 +0000

Introduction

This is a simple code snippet which is used to make an Auto Complete ComboBox.

Using the code

Usage: Call the subroutine from within the ComboBox’s KeyPress event handler.


AutoComplete(ByRef cb As ComboBox, ByVal e As System.Windows.Forms.KeyPressEventArgs, Optional ByVal blnLimitToList As Boolean = False)

cb – ComboBox used to make the Auto Complete ComboBox.
e – System.Windows.Forms.KeyPressEventArgs used to handle the keyboard inputs.
blnLimitToList – Optional Boolean value indicating whether the user input is limited to the list values or not.

Code


    ' AutoComplete
    Public Sub AutoComplete(ByRef cb As ComboBox, ByVal e As System.Windows.Forms.KeyPressEventArgs, Optional ByVal blnLimitToList As Boolean = False)
        Dim strFindStr As String

        If e.KeyChar = Chr(8) Then  'Backspace
            If cb.SelectionStart <= 1 Then
                cb.Text = ""
                Exit Sub
            End If
            If cb.SelectionLength = 0 Then
                strFindStr = cb.Text.Substring(0, cb.Text.Length - 1)
            Else
                strFindStr = cb.Text.Substring(0, cb.SelectionStart - 1)
            End If
        Else
            If cb.SelectionLength = 0 Then
                strFindStr = cb.Text & e.KeyChar
            Else
                strFindStr = cb.Text.Substring(0, cb.SelectionStart) & e.KeyChar
            End If
        End If

        Dim intIdx As Integer = -1

        ' Search the string in the Combo Box List.
        intIdx = cb.FindString(strFindStr)

        If intIdx <> -1 Then ' String found in the List.
            cb.SelectedText = ""
            cb.SelectedIndex = intIdx
            cb.SelectionStart = strFindStr.Length
            cb.SelectionLength = cb.Text.Length
            e.Handled = True
        Else
            If blnLimitToList = True Then
                e.Handled = True
            Else
                e.Handled = False
            End If
        End If
    End Sub

History

Released on July 30^th, 2005.

Auto Complete ComboBox – C# Windows Forms

Solomon — Tue, 24 Feb 2009 04:38:37 +0000

Introduction

This is a simple code snippet which is used to make an Auto Complete ComboBox.

Using the code

Usage: Call the function AutoComplete from within the ComboBox’s KeyPress event handler.


AutoComplete(ComboBox cb, System.Windows.Forms.KeyPressEventArgs e, bool blnLimitToList)

Code


        /// 
        /// AutoComplete
        /// 
        /// ComboBox
        /// KeyPressEventArgs
        /// Limit to List
		public void AutoComplete(ComboBox cb, System.Windows.Forms.KeyPressEventArgs e, bool blnLimitToList)
		{
			string strFindStr = "";

			if (e.KeyChar == (char)8)
			{
				if (cb.SelectionStart <= 1)
				{
					cb.Text = "";
					return;
				}

				if (cb.SelectionLength == 0)
					strFindStr = cb.Text.Substring(0, cb.Text.Length - 1);
						else
					strFindStr = cb.Text.Substring(0, cb.SelectionStart - 1);
					}
			else
			{
				if (cb.SelectionLength == 0)
					strFindStr = cb.Text + e.KeyChar;
				else
					strFindStr = cb.Text.Substring(0, cb.SelectionStart) + e.KeyChar;
			}

			int intIdx = -1;

			// Search the string in the ComboBox list.

			intIdx = cb.FindString(strFindStr);

			if (intIdx != -1)
			{
				cb.SelectedText = "";
				cb.SelectedIndex = intIdx;
				cb.SelectionStart = strFindStr.Length;
				cb.SelectionLength = cb.Text.Length;
				e.Handled = true;
			}
			else
			{
				e.Handled = blnLimitToList;
			}
		}

History

Released on November 8th 2006.

Solomon » Auto Complete ComboBox

Auto Complete ComboBox – VB.NET Windows Forms

Introduction

Using the code

Code

History

Auto Complete ComboBox – C# Windows Forms

Introduction

Using the code

Code

History