如何用于每个控件并将其添加到元组(标签))

Question

我如何使用for each control并将其添加到Tuple (of Label))

错误我得到

(类型'元组(控制(的值不能转换为'元组(标签((

这是我的代码

Private first As List(Of Tuple(Of Label))
Private Sub Button1_Click(sender As Object, e As EventArgs) Handles Button1.Click
    first = New List(Of Tuple(Of Label))
    For Each cntl As Control In Controls
        first.Add(Tuple.Create(cntl))
    next
End Sub

Answer 1

Control.OfType(Of Label)过滤非标签

并使用 Label作为循环变量

Private first As List(Of Tuple(Of Label))
Private Sub Button1_Click(sender As Object, e As EventArgs) Handles Button1.Click
    first = New List(Of Tuple(Of Label))
    For Each cntl As Label In Controls.OfType(Of Label)()
        first.Add(Tuple.Create(cntl))
    Next
End Sub

Answer 2

如果您的列表需要保留为Tuple(Of Label)，则需要将控件投放为Label。您可以使用Dim convertedControl = cntl as Label

实现此目标

否则，如果原始元组没有为，则可以将其定义为Tuple(Of Control)。