IOrderedEnumerable到vb.net的转换

Question

Private Sub UpdateListBox(message As String)
    Dim beeGroups As IOrderedEnumerable(Of IGrouping(Of BeeState, Bee)) = From beeGroup In From bee In Me.world.BeesGroup bee By bee.CurrentStateOrder By beeGroup.KeybeeGroup
    Me.listBox1.Items.Clear()
    For Each beeGroup As IGrouping(Of BeeState, Bee) In beeGroups
        Dim s As String
        s = If(beeGroup.Count() = 1, String.Empty, "s")
        Me.listBox1.Items.Add(Convert.ToString(beeGroup.Key) & ": " & beeGroup.Count() & " bee" & s)
        If beeGroup.Key <> BeeState.Idle OrElse beeGroup.Count() <> Me.world.Bees.Count() OrElse Me.framesRun <= 0 Then
            Continue For
        End If
        Me.listBox1.Items.Add("Simulation ended: all bees are idle")
        Me.toolStripButtonStartSimulation.Text = "Simulation ended."
        Me.statusStrip1.Items(0).Text = "Simulation ended"
        Me.timer1.Enabled = False
    Next
End Sub    

在c#项目到vb.net的转换中，我完全被这个错误卡住了。

我知道在c#中它是这样的

IOrderedEnumerable<IGrouping<BeeState, Bee>> beeGroups = from bee in this.world.Bees
                                                                 group bee by bee.CurrentState
                                                                 into beeGroup orderby beeGroup.Key select beeGroup;    

但是一旦转换成vb.net，它试图用最少的声明在一行中陈述所有内容。

而在c#中你也可以逃脱c#:

foreach (IGrouping<BeeState, Bee> beeGroup in beeGroups)    

vb.net试图在自身内部声明for语句:

For Each group As var In beeGroups    

Answer 1

Private Sub UpdateListBox(message As String)
    Dim beeGroups = From bee In Me.world.Bees
                    Group By bee.CurrentState Into beeGroup = Group
                    Order By beeGroup.Key
    Me.listBox1.Items.Clear()
    For Each beeGroup In beeGroups
        Dim beeCount = beeGroup.Count ' to avoid reevaluation
        Dim s = If(beeCount >= 1, String.Empty, "s")
        Me.listBox1.Items.Add(Convert.ToString(beeGroup.Key) & ": " & beeCount & " bee" & s)
        If beeGroup.Key <> BeeState.Idle OrElse beeCount <> Me.world.Bees.Count OrElse Me.framesRun <= 0 Then
            Continue For
        End If
        Me.listBox1.Items.Add("Simulation ended: all bees are idle")
        Me.toolStripButtonStartSimulation.Text = "Simulation ended."
        Me.statusStrip1.Items(0).Text = "Simulation ended"
        Me.timer1.Enabled = False
    Next
End Sub

Answer 2

你的'For Each'语句是正确的(你的c#和VB版本都在循环头中声明了迭代器变量)，但是VB的LINQ查询应该是:

Dim beeGroups As IOrderedEnumerable(Of IGrouping(Of BeeState, Bee)) = From bee In Me.world.Bees
                                                                      Group bee By bee.CurrentState Into beeGroup = Group
                                                                      Order By CurrentState
                                                                      Select beeGroup

或用户选项Infer On:

Dim beeGroups = From bee In Me.world.Bees
                Group bee By bee.CurrentState Into beeGroup = Group
                Order By CurrentState
                Select beeGroup