类型 "Record" 未在自定义 class vb.net 中定义

Question

我正在按照下面的主题创建多行组合框。我目前使用的是 Visual Studio 2019，该线程来自 2013。

Any way for a combo box with 2 values per line?

我复制的代码：

    Public Class MultiLineComboBox : Inherits ComboBox
   Public Sub New()
      ' Call the base class.
      MyBase.New()

      ' Typing a value into this combobox won't make sense, so make it impossible.
      Me.DropDownStyle = ComboBoxStyle.DropDownList

      ' Set the height of each item to be twice its normal value
      ' (because we have two lines instead of one).
      Me.ItemHeight *= 2
   End Sub

   Protected Overrides Sub OnDrawItem(e As DrawItemEventArgs)
      ' Call the base class.
      MyBase.OnDrawItem(e)

      ' Fill the background.
      e.DrawBackground()

      ' Extract the Record object corresponding to the combobox item to be drawn.
      If (e.Index >= 0) Then
         Dim record As Record = DirectCast(Me.Items(e.Index), Record)

         ' Format the item's caption string.
         Dim caption As String = String.Format("ID: {0}{1}Name: {2}", record.UniqueID.ToString(), Environment.NewLine, record.Name)

         ' And then draw that string, left-aligned and vertically centered.
         TextRenderer.DrawText(e.Graphics, caption, e.Font, e.Bounds, e.ForeColor, TextFormatFlags.Left Or TextFormatFlags.VerticalCenter)
      End If

      ' Finally, draw the focus rectangle.
      e.DrawFocusRectangle()
   End Sub
End Class

我创建了一个名为 MultiLineComboBox 的 class，完全按照说明操作，它显示“未定义类型 'Record'”。我一直在寻找关于“记录”或 DirectCast 类型的答案（例如 https://docs.microsoft.com/en-us/dotnet/visual-basic/language-reference/operators/directcast-operator），但到目前为止 none 对我有帮助。

我的声誉目前 <50，所以我也不能对该线程的答案发表评论。大家能帮我解决一下吗？

（添加了标签 visual-studio-2019 和 .net-4.7.2 以防 VS 或 .NET 版本出现问题）

Answer 1

阅读整个答案。 Record class 在那里声明；您也需要它，并且您想要更改代码以匹配组合框的字段。

类型 "Record" 未在自定义 class vb.net 中定义

Type "Record" is not defined in custom class vb.net

vb.net

combobox

winforms

.net-4.7.2

visual-studio-2019