如何在C# / Winforms中将队列绑定到DataGridView？

Question

我有一个标准的C#队列，声明如下：

private Queue<DeployJob> _solutionQueue = new Queue<DeployJob>();

现在我想将这个队列绑定到一个放置在窗体内的 DataGridView 上。所谓“绑定”，是指每次从队列中执行 dequeue 或 enqueue 操作时，DataGridView 都会被更新（以便始终表示队列的状态）。

我尝试过以下方式进行绑定：

jobGridView.DataSource = _solutionQueue;

但是，即使我使用update或refresh方法，它也无法正常工作。如果您需要更多的代码，请随时询问 :)

- LMW-HH

Answer 1

根据 MSDN，DataGridView.DataSource 必须实现以下接口之一：

• IList
• IListSource
• IBindingList
• IBindingListView

Queue<T> 类实现了 IList 的父接口，包括 IEnumerable 和 ICollection，但不包括 IList 本身。

一种建议是使用 LINQ 从队列中创建 List<DeployJob>，然后进行绑定。

using System.Linq;    

//code

jobGridView.DataSource = _solutionQueue.ToList();

您需要确保处理更新/修改队列的任何事件，并重新绑定DataGridView到新创建的List。

- kaveman

Answer 2

我创建了一个通用队列类型，使队列可观察，并创建了一个派生类型，使这个新队列的行为类似于列表和绑定列表。这适用于DataGridView的只读功能。如果需要其他功能，您需要进一步扩展。

可观察并发队列：

Imports System.Collections.Concurrent
Imports System.Collections.Specialized

Public Class ObservableConcurrentQueue(Of T)
    Inherits ConcurrentQueue(Of T)
    Implements INotifyCollectionChanged

    Public Event CollectionChanged(sender As Object, e As NotifyCollectionChangedEventArgs) Implements INotifyCollectionChanged.CollectionChanged
    Private Sub OnCollectionChanged(ByVal args As NotifyCollectionChangedEventArgs)
        RaiseEvent CollectionChanged(Me, args)
    End Sub

    Public Shadows Sub Enqueue(ByVal item As T)
        MyBase.Enqueue(item)
        OnCollectionChanged(New NotifyCollectionChangedEventArgs(NotifyCollectionChangedAction.Add, item))
    End Sub

    Public Shadows Function TryDequeue(ByRef result As T) As Boolean
        If Not MyBase.TryDequeue(result) Then
            Return False
        End If

        OnCollectionChanged(New NotifyCollectionChangedEventArgs(NotifyCollectionChangedAction.Remove, result))

        Return True
    End Function

End Class

进一步包装它，使其表现得像列表和绑定列表：

Imports System.Linq
Imports System.ComponentModel
Imports System.Collections.Specialized
Imports System.Linq.Expressions

Public Class ObservableConcurrentQueueList(Of T)
    Inherits ObservableConcurrentQueue(Of T)
    Implements IList(Of T), IBindingList

    Public Sub Clear()
        Dim item As T
        While (Not IsEmpty())
            MyBase.TryDequeue(item)
        End While
    End Sub

#Region "IList Implementation"

    Public Sub Add1(item As T) Implements ICollection(Of T).Add
        MyBase.Enqueue(item)
    End Sub

    Protected Sub Clear1() Implements ICollection(Of T).Clear
        Clear()
    End Sub

    Protected Function Contains1(item As T) As Boolean Implements ICollection(Of T).Contains
        Return MyBase.Contains(item)
    End Function

    Protected Sub CopyTo1(array() As T, arrayIndex As Integer) Implements ICollection(Of T).CopyTo
        MyBase.CopyTo(array, arrayIndex)
    End Sub

    Protected ReadOnly Property Count1 As Integer Implements ICollection(Of T).Count
        Get
            Return MyBase.Count
        End Get
    End Property

    Protected ReadOnly Property IsReadOnly1 As Boolean Implements ICollection(Of T).IsReadOnly
        Get
            Return True
        End Get
    End Property

    Protected Function Remove1(item As T) As Boolean Implements ICollection(Of T).Remove
        Throw New NotImplementedException
    End Function

    Protected Function IndexOf1(item As T) As Integer Implements IList(Of T).IndexOf
        Return Me.ToList.IndexOf(item)
    End Function

    Protected Sub Insert1(index As Integer, item As T) Implements IList(Of T).Insert
        Throw New NotImplementedException
    End Sub

    Protected Property Item1(index As Integer) As T Implements IList(Of T).Item
        Get
            Return Me.ToList.Item(index)
        End Get
        Set(value As T)
            Throw New NotImplementedException
        End Set
    End Property

    Protected Sub RemoveAt1(index As Integer) Implements IList(Of T).RemoveAt
        Throw New NotImplementedException
    End Sub

#End Region

#Region "IBindList Implementation"

    Protected Function Add2(value As Object) As Integer Implements IList.Add
        'Throw New NotImplementedException
        MyBase.Enqueue(value)
        Return Nothing
    End Function

    Protected Sub Clear2() Implements IList.Clear
        Clear()
    End Sub

    Protected Function Contains2(value As Object) As Boolean Implements IList.Contains
        Return MyBase.Contains(value)
    End Function

    Protected Function IndexOf2(value As Object) As Integer Implements IList.IndexOf
        Return Me.ToList.IndexOf(value)
    End Function

    Protected Sub Insert2(index As Integer, value As Object) Implements IList.Insert
        Throw New NotImplementedException
    End Sub

    Protected ReadOnly Property IsFixedSize2 As Boolean Implements IList.IsFixedSize
        Get
            Return False
        End Get
    End Property

    Protected ReadOnly Property IsReadOnly2 As Boolean Implements IList.IsReadOnly
        Get
            Return True
        End Get
    End Property

    Protected Overloads Property Item2(index As Integer) As Object Implements IList.Item
        Get
            Return Me.ToList.Item(index)
        End Get
        Set(value As Object)
            Throw New NotImplementedException
        End Set
    End Property

    Protected Sub Remove2(value As Object) Implements IList.Remove
        Throw New NotImplementedException
    End Sub

    Protected Sub RemoveAt2(index As Integer) Implements IList.RemoveAt
        Throw New NotImplementedException
    End Sub

    Protected Sub AddIndex2([property] As PropertyDescriptor) Implements IBindingList.AddIndex

    End Sub

    Protected Function AddNew2() As Object Implements IBindingList.AddNew
        Throw New NotImplementedException
    End Function

    Protected ReadOnly Property AllowEdit2 As Boolean Implements IBindingList.AllowEdit
        Get
            Return False
        End Get
    End Property

    Protected ReadOnly Property AllowNew2 As Boolean Implements IBindingList.AllowNew
        Get
            Return False
        End Get
    End Property

    Protected ReadOnly Property AllowRemove2 As Boolean Implements IBindingList.AllowRemove
        Get
            Return False
        End Get
    End Property

    Protected Sub ApplySort2([property] As PropertyDescriptor, direction As ListSortDirection) Implements IBindingList.ApplySort
        Throw New NotImplementedException
    End Sub

    Protected Function Find2([property] As PropertyDescriptor, key As Object) As Integer Implements IBindingList.Find
        Throw New NotImplementedException
        Return Nothing
    End Function

    Protected ReadOnly Property IsSorted2 As Boolean Implements IBindingList.IsSorted
        Get
            Return False
        End Get
    End Property

    Protected Event ListChanged2(sender As Object, e As ListChangedEventArgs) Implements IBindingList.ListChanged

    Protected Sub RemoveIndex2([property] As PropertyDescriptor) Implements IBindingList.RemoveIndex
        Throw New NotImplementedException
    End Sub

    Protected Sub RemoveSort2() Implements IBindingList.RemoveSort
        'Throw New NotImplementedException
    End Sub

    Protected ReadOnly Property SortDirection2 As ListSortDirection Implements IBindingList.SortDirection
        Get
            'Throw New NotImplementedException
        End Get
    End Property

    Protected ReadOnly Property SortProperty2 As PropertyDescriptor Implements IBindingList.SortProperty
        Get
            Throw New NotImplementedException
            Return Nothing
        End Get
    End Property

    Protected ReadOnly Property SupportsChangeNotification2 As Boolean Implements IBindingList.SupportsChangeNotification
        Get
            Return True
        End Get
    End Property

    Protected ReadOnly Property SupportsSearching2 As Boolean Implements IBindingList.SupportsSearching
        Get
            Return False
        End Get
    End Property

    Protected ReadOnly Property SupportsSorting2 As Boolean Implements IBindingList.SupportsSorting
        Get
            Return False
        End Get
    End Property

#End Region

End Class

在表单中使用它：

Private Sub Form_Load(sender As Object, e As EventArgs) Handles MyBase.Load

    DataGridView1.AutoGenerateColumns = True
    Me.DataGridView1.DataSource = MyObservableQueueList

    AddHandler MyObservableQueueList.CollectionChanged, AddressOf UpdateGrid
End Sub

Private Sub UpdateGrid(sender As Object, e As System.Collections.Specialized.NotifyCollectionChangedEventArgs)
    Me.MyObservableQueueList.DataSource = Nothing
    Me.MyObservableQueueList.DataSource = _AlarmHistory
End Sub

Protected Overrides Sub Dispose(ByVal disposing As Boolean)
    Try
        RemoveHandler MyObservableQueueList.CollectionChanged, AddressOf UpdateGrid
        If disposing AndAlso components IsNot Nothing Then
            components.Dispose()
        End If
    Finally
        MyBase.Dispose(disposing)
    End Try
End Sub

- VoteCoffee