使用suggestappend

Question

我有一个带有AutoComplete.SuggestAppend的数据绑定ListItems组合框 并且想要使用向上/向下箭头键从组合框导航到不同的控件，而不是滚动项目。

问题是如果文字没有完成，建议的文字会在下一个控件有焦点时保持高亮显示。

Link to image example

以下是一些代码，显示了我正在做的一个简单示例

Public Class Form1
Dim PreventCboBoxChanging As Boolean

Private Sub Form1_Load(sender As Object, e As EventArgs) Handles MyBase.Load
    ComboBox1.DataSource = New List(Of String)(New String() {10, 11, 20, 30})
    ComboBox1.AutoCompleteSource = AutoCompleteSource.ListItems
    ComboBox1.AutoCompleteMode = AutoCompleteMode.SuggestAppend
End Sub

Private Sub ComboBox1_KeyDown(sender As Object, e As KeyEventArgs) Handles ComboBox1.KeyDown
    If PreventCboBoxChanging = True Then
        e.Handled = True
    End If
    PreventCboBoxChanging = False
End Sub

Private Sub ComboBox1_PreviewKeyDown(sender As Object, e As PreviewKeyDownEventArgs) Handles ComboBox1.PreviewKeyDown
    If e.KeyCode = Keys.Down Or e.KeyCode = Keys.Up Then
        PreventCboBoxChanging = True
        TextBox1.Select()
    End If
End Sub

Private Sub TextBox1_KeyDown(sender As Object, e As KeyEventArgs) Handles TextBox1.KeyDown
    If e.KeyCode = Keys.Down Or e.KeyCode = Keys.Up Then
        ComboBox1.Select()
    End If
End Sub

Private Sub ComboBox1_Validating(sender As Object, e As System.ComponentModel.CancelEventArgs) Handles ComboBox1.Validating
    Dim index As Integer = sender.FindString(sender.Text)
    If index > -1 Then
        sender.SelectedIndex = index
    Else
        e.Cancel = True
        Me.Text = ""
        Beep()
    End If


End Sub

结束班

有没有办法取消选择文字？

Answer 1

我在另一个帖子中找到了解决方案。需要关闭Combobox自动完成模式，更改焦点，然后在PreviewKeyDown事件下重新启用SuggestAppend模式。

    Private Sub ComboBox1_PreviewKeyDown(sender As Object, e As PreviewKeyDownEventArgs) Handles ComboBox1.PreviewKeyDown
    If e.KeyCode = Keys.Down Or e.KeyCode = Keys.Up Then
        ComboBox1.AutoCompleteMode = AutoCompleteMode.None
        TextBox1.Select()
        ComboBox1.AutoCompleteMode = AutoCompleteMode.SuggestAppend
    End If
End Sub

Answer 2

这应该成功：

Private Sub ComboBox1_Leave(sender As Object, e As EventArgs) Handles ComboBox1.Leave
    ComboBox1.SelectionLength = 0
End Sub