Question

我在我的项目中创建了userControl Node，其定义如下：

<UserControl x:Class="ProjectCrow.Node"
         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:local="clr-namespace:ProjectCrow"
         mc:Ignorable="d" 
         d:DesignHeight="300" d:DesignWidth="300">

<Border Name="border"  BorderBrush="Black" BorderThickness="1">

    <DockPanel LastChildFill="True"  Background="AliceBlue" Height="45" Canvas.Top="90" Width="160" MouseRightButtonDown="OnNodeDeselect" MouseLeftButtonDown="OnNodeClick"   >

        <Border BorderBrush="Black" BorderThickness="1" DockPanel.Dock="Left">
            <Image Name="img"  />
        </Border>


        <Border BorderBrush="Black" BorderThickness="1" DockPanel.Dock="Bottom" Height="10" >
            <TextBlock Name="protocol" VerticalAlignment="Center" Background="Gold"     TextAlignment="Center"  TextWrapping="Wrap"> FFI
            </TextBlock>
        </Border>


        <Border BorderBrush="Black" BorderThickness="1" DockPanel.Dock="Top">
            <TextBlock Name="nodeName"  VerticalAlignment="Center"     TextAlignment="Center"  TextWrapping="Wrap">UNIT
            </TextBlock>
        </Border>

    </DockPanel>
</Border>

我在我的应用程序中多次使用它。基本上它表示一个节点，具有已定义的IP和端口，您可以从中获取一些数据。

我创建了一个组合框，供用户用来选择从哪个源节点收集数据。我使用数据绑定来获取当前可用节点的列表。

        sourcesBox.SetBinding(ComboBox.ItemsSourceProperty, new Binding() { Source = MainUI.mainWindow.sources});
        sourcesBox.DisplayMemberPath = "NameString";
        sourcesBox.SelectedValuePath = "NameString";

MainUI.mainWindow.Sources为public ObservableCollection<Node> sources;

的位置

我还将为您提供部分Node类的实现

    public partial class Node : UserControl
{

    bool selected = false;

    string name;

    public string NameString
    {
        get { return name; }

        set { if (name != value)
            {
                name = value;
                NotifyPropertyChanged("NameString");
            }
        }
    }


    public virtual event PropertyChangedEventHandler PropertyChanged;
    protected virtual void NotifyPropertyChanged(params string[] propertyNames)
    {
        if (PropertyChanged != null)
        {
            foreach (string propertyName in propertyNames) PropertyChanged(this, new PropertyChangedEventArgs(propertyName));
            PropertyChanged(this, new PropertyChangedEventArgs("HasError"));
        }
    }


    public Node()
    {
        InitializeComponent();
    }

ComboBox正确显示当前可用的所有可能节点，但如果我选择了某些内容，则不会显示SelectedValue。

我该如何解决这个问题？

Answer 1

您应该能够使用SelectedValue属性将所选数据对象绑定到ComboBox（我相信SelectedItem属性是只读的）。如果必须在代码中设置此绑定，则可以这样做：

ComboBox Box = new ComboBox();
Binding b = new Binding()
{
    Source = YourViewModel, 
    Path = new PropertyPath("YourViewModelProperty"),
    Mode = BindingMode.TwoWay
};
Box.SetBinding(ComboBox.SelectedValueProperty, b);

或者在XAML（我的首选方法）中：

<ComboBox SelectedValue="{Binding YourViewModelProperty, Mode=TwoWay}">
    <ComboBox.ItemTemplate>
        <DataTemplate>
            <!--Your UserControl goes here-->
        </DataTemplate>
    </ComboBox.ItemTemplate>
</ComboBox>

ComboBox绑定到未显示所选值的UserControl列表

1 个答案: