Question

我想将DataGrid绑定到包含嵌套集合的对象集合，因为每个行的值的数量在运行时都是未定义的。

我有一个名为 Record

的课程

Public Class Record
    Private _timestamp As DateTime
    Private _deviceName As String
    Private _values As List(Of Double)
    Public Property Timestamp As DateTime
        Get
            Return _timestamp
        End Get
        Set(value As DateTime)
            _timestamp = value
        End Set
    End Property
    Public Property DeviceName As String
        Get
            Return _deviceName
        End Get
        Set(value As String)
            _deviceName = value
        End Set
    End Property
    Public Property Values As List(Of Double)
        Get
            Return _values
        End Get
        Set(value As List(Of Double))
            _values = value
        End Set
    End Property
    Public Sub New(ByVal timestamp As DateTime, ByVal deviceName As String, ByVal values As List(Of Double))
        Me.Timestamp = timestamp
        Me.DeviceName = deviceName
        Me.Values = values
    End Sub
End Class

以及记录对象

的集合

Dim records As ObservableCollection(Of Record)
records = New ObservableCollection(Of Record)
With records
    .Add(New Record(Now, "DEV1", New List(Of Double) From {0.1, 0.2, 0.3}))
    .Add(New Record(Now, "DEV2", New List(Of Double) From {1.1, 1.2, 1.3}))
    .Add(New Record(Now, "DEV3", New List(Of Double) From {2.1, 2.2, 2.3}))
End With

我不知道如何将来自属性值的值绑定到XAML中的列。

我应该如何将属性绑定到XAML datagrid的列？标题怎么样？我该怎么设置它们？

我想要获得的是

+------------+--------+--------+--------+--------+
| DATE       | DEVICE | VALUE1 | VALUE2 | VALUE3 |
+------------+--------+--------+--------+--------+
| 2014/10/17 | DEV1   | 0.1    | 0.2    | 0.3    |
| 2014/10/17 | DEV2   | 1.1    | 1.2    | 1.3    |
| 2014/10/17 | DEV3   | 2.1    | 2.2    | 2.3    |
+------------+--------+--------+--------+--------+

编辑根据Mike的建议，我实现了一个ITypedList接口。类 Datalog 实现ITypedList，是 DataLogRecord 对象的ArrayList。 DataLogRecord 对象有2个属性（Timestamp和DeviceName），第三个属性是 DataLogValueCollection （即 DataLogValue 的ArrayList）。

Imports System.ComponentModel
Public Class DataLog
    Inherits ArrayList
    Implements ITypedList
    Private Function GetItemProperties(ByVal listAccessors() As PropertyDescriptor) As PropertyDescriptorCollection Implements ITypedList.GetItemProperties
        Return TypeDescriptor.GetProperties(GetType(DataLogRecord))
    End Function
    Private Function GetListName(ByVal listAccessors() As PropertyDescriptor) As String Implements ITypedList.GetListName
        Return "DataLogRecord"
    End Function
End Class

Public Class DataLogRecord
    Private _timestamp As DateTime
    Private _deviceName As String
    Private _values As DataLogValueCollection
    Public Property Timestamp As DateTime
        Get
            Return _timestamp
        End Get
        Set(value As DateTime)
            _timestamp = value
        End Set
    End Property
    Public Property DeviceName As String
        Get
            Return _deviceName
        End Get
        Set(value As String)
            _deviceName = value
        End Set
    End Property
    Public Property Values As DataLogValueCollection
        Get
            Return _values
        End Get
        Set(value As DataLogValueCollection)
            _values = value
        End Set
    End Property
    Public Sub New(ByVal timestamp As DateTime, ByVal deviceName As String,
                   ByVal values As DataLogValueCollection)
        Me.Timestamp = timestamp
        Me.DeviceName = deviceName
        Me.Values = values
    End Sub
End Class

Imports System.ComponentModel
Public Class DataLogValueCollection
    Inherits ArrayList
    Implements ITypedList
    Private Function GetItemProperties(ByVal listAccessors() As PropertyDescriptor) As PropertyDescriptorCollection Implements ITypedList.GetItemProperties
        Return TypeDescriptor.GetProperties(GetType(DataLogValue))
    End Function
    Private Function GetListName(ByVal listAccessors() As PropertyDescriptor) As String _
    Implements ITypedList.GetListName
        Return "DataLogValue"
    End Function
End Class

Public Class DataLogValue
    Private _value As Nullable(Of Double) = Nothing
    Private _name As String = Nothing
    Public Property Value As Nullable(Of Double)
        Get
            Return _value
        End Get
        Set(value As Nullable(Of Double))
            _value = Value
        End Set
    End Property
    Public Property Name As String
        Get
            Return _name
        End Get
        Set(value As String)
            _name = Value
        End Set
    End Property
    Public Sub New()
    End Sub
    Public Sub New(ByVal value As Nullable(Of Double), ByVal name As String)
        Me.Value = value
        Me.Name = name
    End Sub
End Class

网格定义

<DataGrid Name="DataGridValues" Height="Auto" Width="Auto" 
        AutoGenerateColumns="True" 
        Style="{StaticResource DataGridStyle}"
        CellStyle="{StaticResource DataGridCellEventStyle}"
        HorizontalAlignment="Stretch"
        ItemsSource="{Binding DataLog}">
</DataGrid>

现在结果DataGrid是

+------------+------------+--------+--------+--------+
| Timestamp  | DeviceName | Values                   |
+------------+------------+--------+--------+--------+
| 2014/10/17 | DEV1       | (Collection)             |
| 2014/10/17 | DEV2       | (Collection)             |
| 2014/10/17 | DEV3       | (Collection)             |
+------------+------------+--------+--------+--------+

正确创建前2列，而值（来自DataLogValueCollection）显示为单列。我错过了什么？

WPF Datagrid - 绑定集合的集合

0 个答案: