WPF TextBox DataContext 不起作用

Question

拥有一个 WPF 用户控件和一个包含 DevExpress GridControl 的 DockPanel，以及在 GridControl 之后和之外的一个 TextBox：

<UserControl x:Class="HellerOven.Setup.SetupGUI.WatlowView"
         xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
         xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
         xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006" 
         xmlns:d="http://schemas.microsoft.com/expression/blend/2008" 
         xmlns:resx="clr-namespace:HellerOven.Languages"
         xmlns:local="clr-namespace:HellerOven.Setup.SetupGUI"
         xmlns:dx="http://schemas.devexpress.com/winfx/2008/xaml/core"
         xmlns:dxe="http://schemas.devexpress.com/winfx/2008/xaml/editors"
         xmlns:dxg="http://schemas.devexpress.com/winfx/2008/xaml/grid"
         xmlns:dxb="http://schemas.devexpress.com/winfx/2008/xaml/bars"
         mc:Ignorable="d" 
         d:DesignHeight="450" d:DesignWidth="800">
<DockPanel>
    <dxg:GridControl x:Name="WatlowSensorsGrid" EnableSmartColumnsGeneration="True" DockPanel.Dock="Top" ItemsSource="{Binding}" FontSize="14" FontWeight="Medium"  Height="600" Margin="0,20,0,0">
    ...
    </dxg:GridControl>

    <TextBox Text="Alarm activation delay [seconds]" IsReadOnly="True" FontSize="14" Foreground="RoyalBlue" FontWeight="Medium" BorderThickness="0" Height="30"/>
    <TextBox Text="30" Name="alarmActivationDelay" FontSize="14" Foreground="RoyalBlue" FontWeight="Medium" BorderThickness="1" Width="100" Height="30"/>

    <Button Height="35" Width="200" Click="Add_Button_Click" HorizontalAlignment="Center" DockPanel.Dock="Bottom" Margin="0,50,0,0">
        <StackPanel Orientation="Horizontal">
            <Image Source="{dx:DXImage Image=Add_32x32.png}" Stretch="Uniform"/>
            <TextBlock Text="Add Watlow Sensor" VerticalAlignment="Center" Margin="5 0 0 0" FontSize="14"/>
        </StackPanel>
    </Button>
</DockPanel>

在 UserControl 的 C# 构造函数中，我为 GridControl 和 TextBox 指定了单独的 DataContext：

    public WatlowView()
    {
        InitializeComponent();
        WatlowSensorsGrid.DataContext = OvenCollections.Instance.SetupWizard.WatlowSensors;
        alarmActivationDelay.DataContext = OvenCollections.Instance.SetupWizard.alarmActivationDelay;
    }

在程序执行期间，GridControl 及其成员在其分配的 DataContext 中更新，但简单整数“alarmActivationDelay”未在其分配的 DataContext 中更新。我对 DataContext 有什么误解？谢谢。

Answer 1

要查看Gridcontrol的变化可以使用这个

WatlowSensorsGrid.BeginDataUpdate();
WatlowSensorsGrid.ItemsSource = OvenCollections.Instance.SetupWizard.WatlowSensors;
WatlowSensorsGrid.RefreshData();
WatlowSensorsGrid.EndDataUpdate();

对于 textbox ，你可以简单地设置 alarmActivationDelay.Text 但如果你想使用 dataContext ，你必须实现 INotifyPropertyChanged 接口。你可以在这个link看到实现

Answer 2

您没有为 TextBox 的 Text 属性设置绑定，就像对 Grid 所做的那样。理想情况下，您应该设置 Window 的 DataContext，然后使用 Path= 设置每个控件在 XAML 中绑定到的属性。如果您这样做，您也不需要命名每个控件。下面是代码的样子：

    public WatlowView()
{
    InitializeComponent();
    this.DataContext = OvenCollections.Instance.SetupWizard;
    // No longer needed
    // WatlowSensorsGrid.DataContext = OvenCollections.Instance.SetupWizard.WatlowSensors;
    // alarmActivationDelay.DataContext = OvenCollections.Instance.SetupWizard.alarmActivationDelay;
}

这里是相关的 XAML，为网格和文本框设置了绑定：

<DockPanel>
<dxg:GridControl x:Name="WatlowSensorsGrid" EnableSmartColumnsGeneration="True" DockPanel.Dock="Top" ItemsSource="{Binding Path=WatlowSensors}" FontSize="14" FontWeight="Medium"  Height="600" Margin="0,20,0,0">
...
</dxg:GridControl>

<TextBox Text="Alarm activation delay [seconds]" IsReadOnly="True" FontSize="14" Foreground="RoyalBlue" FontWeight="Medium" BorderThickness="0" Height="30"/>
<TextBox Text="{Binding Path=alarmActivationDelay}" Name="alarmActivationDelay" FontSize="14" Foreground="RoyalBlue" FontWeight="Medium" BorderThickness="1" Width="100" Height="30"/>

<Button Height="35" Width="200" Click="Add_Button_Click" HorizontalAlignment="Center" DockPanel.Dock="Bottom" Margin="0,50,0,0">
    <StackPanel Orientation="Horizontal">
        <Image Source="{dx:DXImage Image=Add_32x32.png}" Stretch="Uniform"/>
        <TextBlock Text="Add Watlow Sensor" VerticalAlignment="Center" Margin="5 0 0 0" FontSize="14"/>
    </StackPanel>
</Button>