Question

我尝试了两种不同的代码来从列表框中获取最大的数字，并且两者都给我一个错误，指出从类型ListViewItem到类型Integer的转换无效。任何帮助将不胜感激。

    Dim CurrentHighest As Integer = 0
    For Each item As Integer In listpgrades.Items
        If item > CurrentHighest Then CurrentHighest = item
    Next
    txtHSP.Text = CurrentHighest.ToString



    Dim max As Integer = 0
    Dim result = ""
    For Each s As String In listpgrades.Items
        Dim x = CInt(s.Substring((s.LastIndexOf(":") + 2)))
        If max < x Then
            max = x
            result = s
        End If
    Next
    txtHSP.Text = result

Answer 1

假设我们正在处理ListView ... 首先，您的For Each循环项不能是Integer和ListViewItem。 listpgrades.Items是ListViewItems的集合。

    Dim CurrentHighest As Integer = 0
    For Each item As ListViewItem In ListView1.Items
        If CInt(item.Text) > CurrentHighest Then CurrentHighest = CInt(item.Text)
    Next
    TextBox1.Text = CurrentHighest.ToString

如果我们在谈论ListBox。

    Dim CurrentHighest As Integer = 0
    For Each item In ListBox1.Items
        If CInt(item) > CurrentHighest Then CurrentHighest = CInt(item)
    Next
    TextBox1.Text = CurrentHighest.ToString

如何解决从“ ListViewItem”类型到“ Integer”类型的转换无效。”错误？

1 个答案: