AutoComplete

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


        /// <summary>
        /// AutoComplete
        /// </summary>
        /// <param name="cb">ComboBox</param>
        /// <param name="e">KeyPressEventArgs</param>
        /// <param name="blnLimitToList">Limit to List</param>
		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.