如何将 wpf AutoCompleteBox 转换为所有大写输入

Question

我有一个AutoCompleteBox 作为DataGrid 列类型。像这样：

<DataGridTemplateColumn>
    <DataGridTemplateColumn.CellTemplate>
        <DataTemplate>
            <TextBlock Text="{Binding Path=Thing, UpdateSourceTrigger=PropertyChanged}" />
        </DataTemplate>
    </DataGridTemplateColumn.CellTemplate>

    <DataGridTemplateColumn.CellEditingTemplate>
        <DataTemplate>
            <SLToolkit:AutoCompleteBox Text="{Binding Path=Thing,
                                              UpdateSourceTrigger=PropertyChanged}" />
        </DataTemplate>
    </DataGridTemplateColumn.CellEditingTemplate>
</DataGridTemplateColumn>

但是，我想将用户的输入限制为大写。在TextBoxes 上，我可以这样做，但我无法使用AutoCompleteBoxes。

<DataGridTextColumn Binding="{Binding UpdateSourceTrigger=PropertyChanged, Path=Thing}">
    <DataGridTextColumn.EditingElementStyle>
        <Style TargetType="TextBox">
            <Setter Property="CharacterCasing" Value="Upper" />
        </Style>
    </DataGridTextColumn.EditingElementStyle>
</DataGridTextColumn>

我试过了：

<SLToolkit:AutoCompleteBox Text="{Binding Path=Thing,
                                          UpdateSourceTrigger=PropertyChanged}"
                           TextChanged="AutoComplete_TextChanged" />

有了这个：

private void AutoComplete_TextChanged(object sender, RoutedEventArgs e)
{
     AutoCompleteBox box = sender as AutoCompleteBox;
     if (box == null) return;
     box.Text = box.Text.ToUpper();
}

这种工作除了它向后写。当用户输入一个字符时，光标会回到框的开头，因此下一个单词在前一个单词的前面。如果我写“示例”，我会看到“ELPMAXE”。

有什么想法吗？

Answer 1

我解决了一个类似的问题，我只想在文本框中输入数字，所以我使用了一个行为。如果输入非数字，则删除该字符。我还使用了使用 System.Windows.Interactivity.dll 的交互库（只需将此 DLL 导入您的项目，如果您没有它，它是 blend sdk http://www.microsoft.com/en-us/download/details.aspx?id=10801 的一部分）。

这是简化的 XAML：

    <Window x:Class="Sample.SampleWindow"
            xmlns:main="clr-namespace:MySampleApp"
            xmlns:i="clr-namespace:System.Windows.Interactivity;assembly=System.Windows.Interactivity"
            Title="Sample"
            Height="800"
            Width="1025"
            >
                         <Grid>
                            <TextBox Text="{Binding Path=Entry, Mode=TwoWay, UpdateSourceTrigger=PropertyChanged}"
                                     Width="30"
                                     MaxLength="4"
                                     HorizontalAlignment="Left">
                                <i:Interaction.Behaviors>
                                    <main:KeyPressesWithArgsBehavior 
KeyUpCommand="{Binding KeyUpFilterForUpperCaseSymbols}" />
                                </i:Interaction.Behaviors>
                            </TextBox>
                         </Grid>
    </Window>

使用以下 Behavior 类：

public class KeyPressesWithArgsBehavior : Behavior<UIElement>
{
    #region KeyDown Press DependencyProperty
    public ICommand KeyDownCommand
    {
        get { return (ICommand) GetValue(KeyDownCommandProperty); }
        set { SetValue(KeyDownCommandProperty, value); }
    }

    public static readonly DependencyProperty KeyDownCommandProperty =
        DependencyProperty.Register("KeyDownCommand", typeof (ICommand), typeof (KeyPressesWithArgsBehavior));

    #endregion KeyDown Press DependencyProperty

    #region KeyUp Press DependencyProperty

    public ICommand KeyUpCommand
    {
        get { return (ICommand) GetValue(KeyUpCommandProperty); }
        set { SetValue(KeyUpCommandProperty, value);}
    }

    public static readonly DependencyProperty KeyUpCommandProperty = 
        DependencyProperty.Register("KeyUpCommand", typeof(ICommand), typeof (KeyPressesWithArgsBehavior));

    #endregion KeyUp Press DependencyProperty

    protected override void OnAttached()
    {
        AssociatedObject.KeyDown += new KeyEventHandler(AssociatedUIElementKeyDown);
        AssociatedObject.KeyUp += new KeyEventHandler(AssociatedUIElementKeyUp);
        base.OnAttached();
    }

    protected override void OnDetaching()
    {
        AssociatedObject.KeyDown -= new KeyEventHandler(AssociatedUIElementKeyDown);
        AssociatedObject.KeyUp -= new KeyEventHandler(AssociatedUIElementKeyUp);
        base.OnDetaching();
    }

    private void AssociatedUIElementKeyDown(object sender, KeyEventArgs e)
    {
        if (KeyDownCommand != null)
        {
            ObjectAndArgs oa = new ObjectAndArgs {Args = e, Object = AssociatedObject};
            KeyDownCommand.Execute(oa);
        }
    }

    private void AssociatedUIElementKeyUp(object sender, KeyEventArgs e)
    {
        if (KeyUpCommand != null)
        {
            KeyUpCommand.Execute(AssociatedObject);
        }
    }
}

然后在您的视图模型中，您可以实现该命令。 SampleWindowViewModel.cs：

    public ICommand KeyUpFilterForUpperCaseSymbolsCommand
    {
        get
        {
            if (_keyUpFilterForUpperCaseSymbolsCommand== null)
            {
                _keyUpFilterForUpperCaseSymbolsCommand= new RelayCommand(KeyUpFilterForUpperCaseSymbols);
            }
            return _keyUpFilterForUpperCaseSymbolsCommand;
        }
    }

...

    private void KeyUpFilterForUpperCaseSymbols(object sender)
    {
        TextBox tb = sender as TextBox;
        if (tb is TextBox)
        {
            // check for a lowercase character here
            // then modify tb.Text, to exclude that character.
            // Example: tb.Text = oldText.Substring(0, x);
        }
    }