How can I bind a Queue to a DataGridView in C#/Winforms?

Question

I have a standard C# queue, declared like this:

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

Now I want to bind this queue to an DataGridView, which is placed inside a winform. With "bind" i mean that everytime i dequeue or enqueue an item from the queue the DataGridView gets updated (so that it always represents the state of the queue).

I have tried to bind it this way:

jobGridView.DataSource = _solutionQueue;

But it doesnt work, even if I use the update or refresh methods. If you need more code, please feel free to ask :)

Answer 1

According to MSDN , the DataGridView.DataSource must implement one of the following interfaces:

• IList
• IListSource
• IBindingList
• IBindingListView

The Queue<T> class implements parent interfaces of IList , including IEnumerable and ICollection , but not IList itself.

One suggestion is to use LINQ to create a List<DeployJob> from the queue and bind like so:

using System.Linq;    

//code

jobGridView.DataSource = _solutionQueue.ToList();

You would want to make sure and handle any events that update/modify the queue, and re-bind the DataGridView to a newly created List

Answer 2

I created a generic queue type that makes a queue observable and a derived type that makes this new queue behave like a list and a binding list. This works for read only features of a datagridview. You would need to extend further if you need additional functionality.

Observable concurrent queue:

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

Wrap it further to behave like a list and abindinglist:

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

Use it in a form:

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