vb.net - 如何在 CheckedListBox vb.net 中添加项目

Question

基本上我有一个选中的列表框，其中的每个项目都有相应的价格。我该如何编码

1) when one of the items is selected, the relating price is stored somewhere in the code, and

2）然后我如何将这些价格相加（例如，如果已经检查了几个项目，我想将价格相加并在文本框中显示总计）。

我在“Visual Studio Express for desktop”上这样做，所以基本上是 vb.net

Answer 1

这是一个概念性示例，我在 Window 窗体项目中使用 Console.WriteLine，其中输出显示在 Visual Studio 的输出窗口中。摘自我不久前写的以下文章，并在这里提供了帮助。

一个 CheckedListBox，一个 Button

Public Class Form1
    Private Sub Form1_Load(sender As Object, e As EventArgs) Handles MyBase.Load
        Dim dt As New DataTable
        dt.Columns.Add(New DataColumn With {.ColumnName = "Identifier",
                                                    .DataType = GetType(Int32),
                                                    .AutoIncrement = True,
                                                    .AutoIncrementStep = 100,
                                                    .AutoIncrementSeed = 100})

        dt.Columns.Add(New DataColumn With {.ColumnName = "ItemName",
                                            .DataType = GetType(String)})

        dt.Columns.Add(New DataColumn With {.ColumnName = "Cost",
                                            .DataType = GetType(Decimal)})

        dt.Columns.Add(New DataColumn With {.ColumnName = "ExtraData",
                                            .DataType = GetType(String)})

        dt.Rows.Add(New Object() {Nothing, "One", 10.99D, "Extra 1"})
        dt.Rows.Add(New Object() {Nothing, "Two", 7D, "Extra 2"})
        dt.Rows.Add(New Object() {Nothing, "Three", 5.99D, "Extra 3"})
        dt.Rows.Add(New Object() {Nothing, "Four", 1.34D, "Extra 4"})
        dt.Rows.Add(New Object() {Nothing, "Five", 45.65D, "Extra 5"})

        clbCheckedListBox.DataSource = dt
        clbCheckedListBox.DisplayMember = "ItemName"

    End Sub

    Private Sub Button1_Click(sender As Object, e As EventArgs) Handles Button1.Click
        If clbCheckedListBox.CheckedItems.Count > 0 Then
            For Each drv As DataRowView In clbCheckedListBox.CheckedItems
                Console.WriteLine("{0} - {1}", drv.Row.Field(Of String)("ItemName"), drv.Row.Field(Of Decimal)("Cost"))
            Next
            Dim total As Decimal = clbCheckedListBox.CheckedItems.Cast(Of DataRowView).Select(Function(view) view.Row.Field(Of Decimal)("Cost")).Sum
            Console.WriteLine(total)
        End If
    End Sub
End Class