我最终改变了主意,我没有使用自动完成文本框,而是使用链接到列表框的常规文本框。如果找到项目,则列表框呈现可见,如果没有,则折叠。
此代码将获取来自 Web 服务的字符串值(值可能来自其他任何地方)并通过验证过程来查看它们是否可以显示在自动完成列表框中
这是我的 XAML 代码:
<StackPanel Orientation="Vertical" Grid.Column="1">
<TextBox x:Name="txtNumeroBon"
Width="{Binding ElementName=PanelBon, Path=ActualWidth}"
Style="{StaticResource TextBoxStyles}"
Margin="8,0,8,0"
TextChanged="txtNumeroBon_TextChanged"/>
<ListBox x:Name="lstNumeroBon"
Visibility="Collapsed"
Margin="8,0,8,0"
Height="150"
SelectionChanged="lstNumeroBon_SelectionChanged"/>
</StackPanel>
这是我的 onTextChanged 方法:
Private Async Function txtNumeroBon_TextChanged(sender As Object, e As TextChangedEventArgs) As Task
Dim lstSearch As List(Of String) = New List(Of String)
lstNumeroBon.Visibility = Windows.UI.Xaml.Visibility.Collapsed
//Only start searching if there are more than 3 characters
If txtNumeroBon.Text.Length > 2 Then
//Get the values for the autocomplete into a list
Dim lstResult = (From p In Await DataService.InstPatronController.GetInstPatron).ToList()
For i = 0 To lstResult.Count - 1
// If the item being searched is bigger than the textbox value
If lstResult(i).Type.ToString.Length > txtNumeroBon.Text.Length Then
//Compare items in lstResult to the textbox value and add if they fit
If lstResult(i).Type.Substring(0, txtNumeroBon.Text.Length).ToLower() = txtNumeroBon.Text.ToLower() Then
lstSearch.Add(lstResult(i).Type.ToString())
End If
End If
Next
//If 1 or more items fit the search
If lstSearch.Count > 0 Then
lstNumeroBon.ItemsSource = lstSearch
lstNumeroBon.Visibility = Windows.UI.Xaml.Visibility.Visible
End If
End If
End Function
这是我的 listboxSelectionChanged 方法:
Private Sub lstNumeroBon_SelectionChanged(sender As Object, e As SelectionChangedEventArgs)
// Verify index to avoid Argument out of range exception
If lstNumeroBon.SelectedIndex < lstNumeroBon.Items.Count - 1 And lstNumeroBon.SelectedIndex > -1 Then
txtNumeroBon.Text = lstNumeroBon.Items(lstNumeroBon.SelectedIndex).ToString()
lstNumeroBon.Visibility = Windows.UI.Xaml.Visibility.Collapsed
End If
End Sub
还可以实现GotFocus和LostFocus方法来显示和隐藏列表框