只需要两步：
1.禁掉输入法：
<Windowx:Class="WpfModelViewApplication1.Views.MainView"
xmlns="/winfx//xaml/presentation"
xmlns:x="/winfx//xaml"
xmlns:input="clr-namespace:System.Windows.Input;assembly=PresentationCore"
Title="MainWindow"Height="400"Width="800">
<Gridx:Name="grid1">
<TextBoxx:Name="tb"Width="100"HorizontalAlignment="Right"Margin="0,164,122,128"input:InputMethod.IsInputMethodEnabled="False"/>
</Grid>
</Window>
第二步 采用正则表达式：Title="MainWindow"Height="400"Width="800">
<Gridx:Name="grid1">
<TextBoxx:Name="tb"Width="100"HorizontalAlignment="Right"Margin="0,164,122,128"input:InputMethod.IsInputMethodEnabled="False"/>
</Grid>
</Window>
第二步 采用正则表达式：
<Windowx:Class="WpfModelViewApplication1.Views.MainView"
xmlns="/winfx//xaml/presentation"
xmlns:x="/winfx//xaml"
xmlns:input="clr-namespace:System.Windows.Input;assembly=PresentationCore"
Title="MainWindow"Height="400"Width="800">
<Gridx:Name="grid1">
<TextBoxx:Name="tb"Width="100"HorizontalAlignment="Right"Margin="0,164,122,128"PreviewTextInput="tb_PreviewTextInput"input:InputMethod.IsInputMethodEnabled="False"/>
</Grid>
</Window>
cs后台代码：
//using System.Text.RegularExpressions;private void tb_PreviewTextInput(object sender, TextCompositionEventArgs e){Regex re = new Regex("[^0-9.-]+");e.Handled = re.IsMatch(e.Text);}
