Question

我有一个组合框绑定到具有Status和StatusID的数据源“StatusListBindingSource”。我需要找到的项目的索引。我将使用索引来设置Me.cmbResult.SelectedIndex

除了我不想使用for / each循环之外，这个工作正常：

Private Sub SetStatusIndex(ByVal StatusValue As Integer)
    Dim ItemIndex As Integer = -1
    Dim ct As Integer = 0
    For Each dView As DataRowView In Me.cmbResult.Items
        If dView.Row.Item("StatusID") = StatusValue Then
            ItemIndex = ct
            Exit For
        End If
        ct += 1
    Next
    Me.cmbResult.SelectedIndex = ItemIndex
End Property

这是我想做的事情：

Dim a As ComboBox.ObjectCollection = Me.cmbResult.Items

'can't cast like this
Dim lisDRView As List(Of DataRowView) = a.Cast(Of DataRowView)()

'I'd like to use something like .find
Dim drView As DataRowView = lisDRView.Find(Function(x) x.Row.Item("StatusID") = StatusValue)

'there is no drView.index so this fails
Me.cmbResult.SelectedIndex = drView.index

但我在a.Cast(Of DataRowView)()上收到例外，当然没有drView.index

InvalidCastException的：无法投射物体类型'd__aa'1 [System.Data.DataRowView]' 输入'System.Collections.Generic.List`1 [System.Data.DataRowView]'。

如何使用find？

获取给定StatusValue的项目索引

Answer 1

这有效：

Dim lis As List(Of DataRowView) = _
        (From item As DataRowView In cmbResult.Items Select item).ToList
Dim d = lis.Find(Function(x As DataRowView) x.Row.Item("StatusID") = StatusValue)
Me.cmbResult.SelectedItem = d

在how to get the all combobox item .... using array

的帮助下

使用对象值查找组合框项目的索引

1 个答案: