如何修复从类型"列表视图项"到类型"整数无效"的转换错误？

Question

我尝试了两种不同的代码来从列表框中获取最高数字，并且它们都给了我一个错误，指出从 ListViewItem 类型到整数类型的转换无效。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

假设我们正在处理列表视图... 在你第一个 For Each 循环项中，不能是整数和列表视图项。列表。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

如果我们谈论的是列表框。

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