Mvvm KeyDown的实现以及TextBox绑定的属性不更新问题的解决
今天写程序的时候遇到了个问题：使用mvvm给TextBox在vm层实现KeyDown键盘事件时，TextBox绑定的vm层属性不更新。
但在TextBox下加个按钮时就更新了。这个问题困扰了我好一会，最后才想起来是更新时机没有给定，所以默认的是LostFocus，故改为PropertyChanged就好了。
1 <Window x:Class="TestDemo1.MainWindow" 2 xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation" 3 xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml" 4 xmlns:cmd="http://www.galasoft.ch/mvvmlight" 5 xmlns:d="http://schemas.microsoft.com/expression/blend/2008" 6 xmlns:i="clr-namespace:System.Windows.Interactivity;assembly=System.Windows.Interactivity" 7 xmlns:ignore="http://www.galasoft.ch/ignore" 8 xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006" 9 Title="MVVM Light Application" 10 Width="300" 11 Height="300" 12 DataContext="{Binding Main, 13 Source={StaticResource Locator}}" 14 mc:Ignorable="d ignore"> 15 16 <Window.Resources> 17 <ResourceDictionary> 18 <ResourceDictionary.MergedDictionaries> 19 <ResourceDictionary Source="Skins/MainSkin.xaml" /> 20 </ResourceDictionary.MergedDictionaries> 21 </ResourceDictionary> 22 </Window.Resources> 23 24 <Grid x:Name="LayoutRoot"> 25 <StackPanel> 26 <TextBlock Margin="0,50,0,0" 27 HorizontalAlignment="Center" 28 VerticalAlignment="Center" 29 FontWeight="Bold" 30 Foreground="Purple" 31 Text="{Binding WelcomeTitle}" 32 TextWrapping="Wrap" /> 33 <TextBox Margin="20" Text="{Binding MyField, UpdateSourceTrigger=PropertyChanged}"> 34 <i:Interaction.Triggers> 35 <i:EventTrigger EventName="KeyDown"> 36 <cmd:EventToCommand Command="{Binding MyTestCommand}" /> 37 </i:EventTrigger> 38 </i:Interaction.Triggers> 39 </TextBox> 40 <Button Height="20" 41 Command="{Binding CmdBtn}" 42 Content="Button" /> 43 </StackPanel> 44 </Grid> 45 </Window>
链接：https://files.cnblogs.com/files/zhangyongheng/TestDemo1.rar
