Question

我正在尝试使用数据绑定填充组合框.Below是我的代码的片段。

XAML：

<ComboBox Name="cmbClientName" ItemsSource="{Binding Path=blClientList}"  DisplayMemberPath="Name" SelectedValuePath="Name" SelectedValue="{Binding Path=blClientList}"/>

'MainWindow'背后的代码：

  Private Sub MainWindow_Loaded(sender As Object, e As RoutedEventArgs) Handles Me.Loaded

  Dim blClientList As ObservableCollection(Of String) = New ObservableCollection(Of String)
  Dim objClientRepository As PET_ClientRepository = New PET_ClientRepository

  For Each objClient As PET_Client In objClientRepository.GetAll()

     blClientList.Add(objClient.Name)
  Next

     Me.cmbClientName.ItemsSource = blClientList
  End Sub

Class1.vb：

Public Property Name As String
    Get
        Return _Name
    End Get
    Set(value As String)
        _Name = value
    End Set
End Property

我想在组合框中看到客户端的名称。上面的代码没有返回任何内容，组合框是空白的。我知道问题在于绑定但是无法弄清楚我做错了什么。

Answer 1

替换它：

Me.cmbClientName.ItemsSource = blClientList

用这个：

Me.DataContext = blClientList

并将XAML更正为：

<ComboBox Name="cmbClientName" ItemsSource="{Binding}"
          DisplayMemberPath="." SelectedValuePath="."/>

Answer 2

这是一个可以帮助您实现理想结果的示例：

Re：你的评论，绑定是好的，你只需要设置上下文

WPF

<Window x:Class="MainWindow"
    xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
    xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
    xmlns:local="clr-namespace:WpfApplication4VB"
    Title="MainWindow" Height="100" Width="293">

    <Window.DataContext>
        <local:Vm />
    </Window.DataContext>

    <Grid>
        <ComboBox ItemsSource="{Binding Collection}" DisplayMemberPath="Name" />
    </Grid>
</Window>

重要的是你添加本地命名空间：

xmlns:local="clr-namespace:WpfApplication4VB"

并设置DataContext

类

Public Class Vm
    Public Property Collection As System.Collections.ObjectModel.ObservableCollection(Of Thing)
    Public Sub New()
        Collection = New ObjectModel.ObservableCollection(Of Thing)()
        Collection.Add(New Thing("Test1"))
        Collection.Add(New Thing("Test2"))
        Collection.Add(New Thing("Test3"))
    End Sub
End Class
Public Class Thing
    Public Property Name As String
    Public Sub New(Name As String)
        Me.Name = Name
    End Sub
End Class

Answer 3

谢谢大家的帮助。

我继续在后面的代码中填充组合框而不是将其绑定到数据源。我甚至不必在XAML中传递“ItemSource”。然而，我确实在Mainwindow.vb中传递了ItemSource，它为我做了诀窍。

以下是正在运行的代码片段：

MainWindow.vb背后的代码

Private Sub MainWindow_Loaded(sender As Object, e As RoutedEventArgs) Handles Me.Loaded

    Me.Username.Text = System.Security.Principal.WindowsIdentity.GetCurrent().Name

    Dim blClientList As ObservableCollection(Of String) = New ObservableCollection(Of String)
    Dim objClientRepository As PET_ClientRepository = New PET_ClientRepository

    For Each objClient As PET_Client In objClientRepository.GetAll()

        blClientList.Add(objClient.Name)

    Next

    Me.cmbClientName.ItemsSource = blClientList

XAML：

<ComboBox Name="cmbClientName" IsReadOnly="True" PresentationTraceSources.TraceLevel="High"/>

Tracelevel没有做任何事情，只是提供调试跟踪支持。

Class1.vb

 Public Property Name As String
    Get
        Return _Name
    End Get
    Set(value As String)
        _Name = value
    End Set
End Property

WPF ComboBox DataBinding vb.net

3 个答案: