VB.net 级联组合框从 Access 连接到数据集 - 更改单位，&小数到分数

发布于 2024-12-07 18:11:46 字数 1988 浏览 0 评论 0原文

我有一个相当复杂的 ComboBox 场景，作为编程新手，我正在努力寻找最好的方法。

我有一个带有数据表的数据集，其中有多个数字数据列。数值数据由以美国标准单位给出的距离组成。我目前已经设置并运行了我的组合框，但我需要以两种方式扩展我目前拥有的内容。

我需要能够将显示的数据列中的小数转换为分数，有没有办法做到这一点并维护数据绑定？在本例中，它是数据源的显示成员...

我需要能够以不同的单位集显示我的下拉选项...我已经编写了单位转换类来帮助解决这个问题，但我不知道我是否也能以某种方式做到这一点并维护数据绑定？我也想转换显示成员上的单位...

Private Sub ComboBox1_SelectedIndexChanged(sender As System.Object, e As System.EventArgs) 处理 ComboBox1.SelectionChangeComfilled
 选择案例 ComboBox1.SelectedItem
    案例“轮胎1”
        使用组合框2
            .DataSource = Tire1BindingSource
            .ValueMember =“OD”
            .DisplayMember = "OD"
        结束于
    案例“轮胎2”
        使用组合框2
            .DataSource = Tire2BindingSource
            .ValueMember =“OD”
            .DisplayMember = "OD"
        结束于
    案例“轮胎3”
        使用组合框2
            .DataSource = Tire3BindingSource
            .ValueMember =“OD”
            .DisplayMember = "OD"
        结束于
    案例“轮毂盖”
        ComboBox3.DataSource = 无
        使用组合框2
            .DataSource = HubcapBindingSource
            .ValueMember =“ID”
            .DisplayMember = "ID"
        结束于
  结束选择
结束子

Private Sub ComboBox2_SelectedIndexChanged(sender As System.Object, e As System.EventArgs) 处理 ComboBox2.SelectionChangeComfilled
选择案例 ComboBox1.SelectedItem
    案例“轮胎1”
        与组合框3
            .DataSource = Tire1BindingSource
            .ValueMember =“ID”
            .DisplayMember = "权重"
        结束于
    案例“轮胎2”
        与组合框3
            .DataSource = Tire2BindingSource
            .ValueMember =“ID”
            .DisplayMember = "权重"
        结束于
    案例“轮胎3”
        与组合框3
            .DataSource = Tire3BindingSource
            .ValueMember =“ID”
            .DisplayMember = "权重"
        结束于
    案例“轮毂盖”
        ComboBox3.DataSource = 无
        使用组合框2
            .DataSource = HubCapBindingSource
            .ValueMember =“ID”
            .DisplayMember = "ID"
        结束于
结束选择

在处理显示分数和单位等问题时使用组合框的最佳方法是什么...

原文

I've got a fairly complex ComboBox scenario, and being new to programming I'm struggling with what the best approach to take is.

I have a DataSet with a DataTable that has several numeric columns of Data. The numeric data is composed of distances given in U.S. Standard units. I currently have my ComboBoxes set up and working, but I need to expand on what I currently have in two ways.

I need to be able to convert the Decimal numbers in my data column being displayed to Fractions, is there a way to do this and maintain databinding? In this case its the Display Member of the data source...

I need to be able to display my drop down options in different sets of units... I've written Unit Conversion classes to help take care of this, but I don't know if I can somehow do this as well and maintain databinding? I'd like to convert the units on the display members as well...

Private Sub ComboBox1_SelectedIndexChanged(sender As System.Object, e As         System.EventArgs) Handles ComboBox1.SelectionChangeCommitted
 Select Case ComboBox1.SelectedItem
    Case "Tire1"
        With ComboBox2
            .DataSource = Tire1BindingSource
            .ValueMember = "OD"
            .DisplayMember = "OD"
        End With
    Case "Tire2"
        With ComboBox2
            .DataSource = Tire2BindingSource
            .ValueMember = "OD"
            .DisplayMember = "OD"
        End With
    Case "Tire3"
        With ComboBox2
            .DataSource = Tire3BindingSource
            .ValueMember = "OD"
            .DisplayMember = "OD"
        End With
    Case "HubCap"
        ComboBox3.DataSource = Nothing
        With ComboBox2
            .DataSource = HubcapBindingSource
            .ValueMember = "ID"
            .DisplayMember = "ID"
        End With
  End Select
End Sub

Private Sub ComboBox2_SelectedIndexChanged(sender As System.Object, e As      System.EventArgs) Handles ComboBox2.SelectionChangeCommitted
Select Case ComboBox1.SelectedItem
    Case "Tire1"
        With ComboBox3
            .DataSource = Tire1BindingSource
            .ValueMember = "ID"
            .DisplayMember = "Weight"
        End With
    Case "Tire2"
        With ComboBox3
            .DataSource = Tire2BindingSource
            .ValueMember = "ID"
            .DisplayMember = "Weight"
        End With
    Case "Tire3"
        With ComboBox3
            .DataSource = Tire3BindingSource
            .ValueMember = "ID"
            .DisplayMember = "Weight"
        End With
    Case "HubCap"
        ComboBox3.DataSource = Nothing
        With ComboBox2
            .DataSource = HubCapBindingSource
            .ValueMember = "ID"
            .DisplayMember = "ID"
        End With
End Select

What is the best approach for using ComboBoxes when dealing with issues such as displaying fractions and units...

分享到QQ

分享到微博