.NET中为组合框添加自动查询功能

在窗体中添加如下方法：

       第一个方法是AutoCompleteKeyUp，它将组合框和KeyEventArgs对象作为参数，需要在组合框的KeyUp事件中调用此方法；它全根据用户输入的内容选择最接近的内容；

       第二个方法是AutoCompleteLeave，在激活组合框的Leave事件时调用，此方法仅提取用户最终选择的内容，按照组合框中的每个匹配内容修改其大小写。

代码如下：

Private Sub AutoCompleteKeyUp(ByVal Combo As ComboBox, ByVal e As KeyEventArgs)         Dim strTyped As String         Dim intFoundIndex As Integer         Dim objFoundItem As Object         Dim strFoundText As String         Dim strAppendText As String         '忽略特殊键         Select Case e.KeyCode             Case Keys.Back, Keys.Left, Keys.Right, Keys.Up, Keys.Down, Keys.Delete, Keys.CapsLock                 Return         End Select         '在查询列表中找到         strTyped = Combo.Text         intFoundIndex = Combo.FindString(strTyped)         If intFoundIndex >= 0 Then             objFoundItem = Combo.Items(intFoundIndex)             strFoundText = Combo.GetItemText(objFoundItem)             strAppendText = strFoundText.Substring(strTyped.Length)             Combo.Text = strTyped & strAppendText             Combo.SelectionStart = strTyped.Length             Combo.SelectionLength = strAppendText.Length         End If     End Sub       Private Sub AutoCompleteLeave(ByVal Combo As ComboBox)         Dim intFoundIndex As Integer         intFoundIndex = Combo.FindStringExact(Combo.Text)         Combo.SelectedIndex = -1         Combo.SelectedIndex = intFoundIndex End Sub       Private Sub ComboBox1_KeyUp(ByVal sender As Object, ByVal e As System.Windows.Forms.KeyEventArgs) Handles ComboBox1.KeyUp         AutoCompleteKeyUp(ComboBox1, e)     End Sub       Private Sub ComboBox1_Leave(ByVal sender As Object, ByVal e As System.EventArgs) Handles ComboBox1.Leave         AutoCompleteLeave(ComboBox1)     End Sub