根据另一个下拉列表更改下拉列表的绑定 [英] Change binding of dropdown list based on another dropdownlist

问题描述

我有2个下拉列表.一个是手动填充的.另一个我想绑定到另一个表，具体取决于第一个表中选择的值.

I have 2 drop-down lists. One is populated manually. The other I would like to bind to a different table depending on the value selected in the first.

Protected Sub ContactType_SelectedIndexChanged(sender As Object, e As System.EventArgs) Handles ContactType.SelectedIndexChanged
    Dim dc As New DataClassesDataContext()
    If ContactType.SelectedItem.Text = "Company" Then
        ContactRelationship.DataSource = dc.CompanyTypes
        ContactRelationship.DataTextField = "CompanyType"
        ContactRelationship.DataValueField = "CompanyTypeID"
        ContactRelationship.DataBind()
    ElseIf ContactType.SelectedItem.Text = "Employee" Then
        ContactRelationship.DataSource = dc.EmployeeTypes
        ContactRelationship.DataTextField = "EmployeeType"
        ContactRelationship.DataValueField = "EmployeeTypeID"
        ContactRelationship.DataBind()
    End If
End Sub

< asp:DropDownList ID ="ContactType" runat ="server" Width ="200px" AutoPostBack ="True">
< asp:ListItem Text ="Company">
< asp:ListItem Text ="Employee">
< asp:ListItem Text =紧急联系人">
< asp:ListItem Text ="Associates">



< asp:DropDownList ID ="ContactRelationship" runat ="server" Width ="200px">



我知道代码是野蛮的，找到解决方案后，我会清理它.
我正在使用asp.net 4.0，Linq to SQL和Sql Server Express 2008r2.

尝试更改ddl1中的值后出现错误.在我看来，ddl2将不会绑定到另一个表，除非它以某种方式未绑定?

我真正需要的只是向正确的方向推进.谢谢您的帮助.

<asp:DropDownList ID="ContactType" runat="server" Width="200px" AutoPostBack="True">
<asp:ListItem Text="Company">
<asp:ListItem Text="Employee">
<asp:ListItem Text="Emergency Contact">
<asp:ListItem Text="Associates">



<asp:DropDownList ID="ContactRelationship" runat="server" Width="200px">



I know the code is barbaric, I''ll clean it up after I find the solution.
I''m using asp.net 4.0, Linq to SQL, and Sql Server express 2008r2.

I''m getting an error after I try to change value in ddl1. It seem to me that ddl2 will not bind to another table until it is somehow unbound?

All I really need is a push in the right direction. Thank you for your help.

推荐答案

jfclrak27，
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点击我 [

Hi jfclrak27,
Go through the following link,
Click me[^]

我将对此进行研究.谢谢你.昨晚我研究了问题，并提出了替代解决方案.我意识到我并不需要绑定ddl到表，只需使用linq将其读入数据集然后绑定到该表即可.

I will look into that. Thank you. I worked on problem last night and came up with an alternate solution. I realized I didn''t really need to bind ddl to table, just use linq to read it into a data set then bind to that.

If ContactType.SelectedItem.Text = "Company" Then
         Dim Types = From t In dc.CompanyTypes
             Select t.CompanyType
         ContactRelationship.DataSource = Types
         ContactRelationship.DataBind()

这对我来说很棒.不知道为什么我全都包裹在车轴上，试图重塑车轮.我正在设计Web应用程序中的向导.

This is working great for me. Don''t know why I got all wrapped around the axle trying to reinvent the wheel. I''m working on designing a wizard in a web app.

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