我有一个带有两个文本框的小WPF窗口,TabIndex为0和1,并且当我按Enter键时,我希望自动从第一个文本框移动焦点到第二个。
注意:这篇文章不是重复的。在这里,我不使用事件处理程序的传统方法,而是使用MVVM模式,正如您所知,代码后台不允许在视图中使用。
我找到了一个解决方案,但我不知道它是否符合MVVM原则。以下是代码:
视图
<Window x:Class="WpfMMVLight2.MainWindow"
xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
xmlns:i="http://schemas.microsoft.com/expression/2010/interactivity"
xmlns:cmd ="http://www.galasoft.ch/mvvmlight"
Title="MainWindow" Height="350" Width="525"
DataContext="{Binding MainViewModel}">
<Grid FocusManager.FocusedElement="{Binding ElementName=tb1}">
<Grid.ColumnDefinitions>
<ColumnDefinition Width="Auto"/>
<ColumnDefinition Width="70"/>
</Grid.ColumnDefinitions>
<Grid.RowDefinitions>
<RowDefinition Height="Auto"/>
<RowDefinition Height="Auto"/>
</Grid.RowDefinitions>
<TextBlock Grid.Column="0" Text="Text 1" VerticalAlignment="Center"/>
<TextBox x:Name="tb1" Grid.Column="1" VerticalAlignment="Center" Margin="5">
<i:Interaction.Triggers>
<i:EventTrigger EventName="KeyDown">
<cmd:EventToCommand PassEventArgsToCommand="True"
Command ="{Binding KeyDownCommand, Mode=OneWay}"/>
</i:EventTrigger>
</i:Interaction.Triggers>
</TextBox>
<TextBlock Grid.Column="0" Grid.Row="1" Text="Text 2" VerticalAlignment="Center"/>
<TextBox x:Name="tb2" Grid.Column="1" Grid.Row="1" VerticalAlignment="Center" Margin="5">
<i:Interaction.Triggers>
<i:EventTrigger EventName="KeyDown">
<cmd:EventToCommand PassEventArgsToCommand="True"
Command ="{Binding KeyDownCommand, Mode=OneWay}"/>
</i:EventTrigger>
</i:Interaction.Triggers>
</TextBox>
</Grid>
ViewModel:
private ICommand _keydownCommand;
public ICommand KeyDownCommand
{
get
{
if (_keydownCommand== null)
_keydownCommand= new DelegateCommand<KeyEventArgs>(KeyDownCommandExecute);
return _keydownCommand;
}
}
private void KeyDownCommandExecute(KeyEventArgs e)
{
if (e != null && e.Key == Key.Enter)
{
TraversalRequest request = new TraversalRequest(FocusNavigationDirection.Next);
request.Wrapped = true;
((Control)e.Source).MoveFocus(request);
}
}
}
我不知道在ViewModel中是否允许使用"Control"类。