长下拉列表值 [英] Long Dropdownlist values

问题描述

我有一个包含30个菜单的下拉列表。我必须根据下拉列表中的选项选中或取消选中一个复选框。



目前我在下面做方法：

 如果（ddlbselect.selectedvalue ==   选项1）
 Chktest.checked =  True  
解决方案
 
很多方法这样做，取决于你如何设置。您可能希望利用以下事实：您可以在下拉列表项中存储两条信息。这是一种方式：
 
 
 
 
 受保护的  Sub  Page_Load（ ByVal  sender  As  对象， ByVal  e  As  System.EventArgs）句柄 我 .Load 
 如果 不 IsPostBack 然后 
  Dim  dt 作为 新 DataTable 
 dt.Columns.Add（  Text）
 dt.Columns.Add（ 数据）
  Dim  dr  As  DataRow = dt.NewRow 
 dt.Rows.Add（ New  对象（）{ Nothing ， Nothing }）
 dt.Rows.Add （新 对象（）{ < span class =code-string> odd，  Checkbox1~Checkbox3~Checkbox5}）
 dt.Rows.Add（ New   Object （）{  even，  Checkbox2~Checkbox4}）
 
 DropDownList1.DataValueField =  数据 
 DropDownList1.DataTextField =   Text 
 DropDownList1.DataSource = dt 
 DropDownList1.DataBind（）
  End  < span class =code-keyword>如果 
 结束  Sub  
 
 私有  Sub  DropDownList1_SelectedIndexChanged（sender  As  对象，e  As  System.EventArgs）句柄 DropDownList1.SelectedIndexChanged 
  If  DropDownList1.SelectedValue.ToString.Length>  0  然后 
  Dim  chks （） As   String  = DropDownList1.SelectedValue.ToString.Split（ 〜）
 对于 i 作为 整数 =  0  至 chks.Length  -   1  
  DirectCast （我 .FindControl（chks（i）），CheckBox）.Checked =  True  
 下一步 
 其他 
 对于 i  As  整数 =  1     5  
  DirectCast （ Me  .FindControl（ 复选框& i），CheckBox）.Checked =  False  
 下一步 
 结束 如果 
 
 结束 < span class =code-keyword> Sub  
 
 
 
 
I have a dropdownlist with 30 menus in it .I have to check or uncheck a checkbox as per the selections from dropdown.



Presently i am doing in below approach :

If (ddlbselect.selectedvalue == "Option 1")
Chktest.checked = True
Please let me know if we have any alternate approach for doing the same , i want to avoid this hardcoding as the list is long.
解决方案
Lots of ways of doing this, depending on how you set things up.  You're likely going to want to take advantage of the fact that you can store two pieces of information in your dropdownlist items. Here's one way:



Protected Sub Page_Load(ByVal sender As Object, ByVal e As System.EventArgs) Handles Me.Load
    If Not IsPostBack Then
        Dim dt As New DataTable
        dt.Columns.Add("Text")
        dt.Columns.Add("Data")
        Dim dr As DataRow = dt.NewRow
        dt.Rows.Add(New Object() {Nothing, Nothing})
        dt.Rows.Add(New Object() {"odd", "Checkbox1~Checkbox3~Checkbox5"})
        dt.Rows.Add(New Object() {"even", "Checkbox2~Checkbox4"})

        DropDownList1.DataValueField = "Data"
        DropDownList1.DataTextField = "Text"
        DropDownList1.DataSource = dt
        DropDownList1.DataBind()
    End If
End Sub

Private Sub DropDownList1_SelectedIndexChanged(sender As Object, e As System.EventArgs) Handles DropDownList1.SelectedIndexChanged
    If DropDownList1.SelectedValue.ToString.Length > 0 Then
        Dim chks() As String = DropDownList1.SelectedValue.ToString.Split("~")
        For i As Integer = 0 To chks.Length - 1
            DirectCast(Me.FindControl(chks(i)), CheckBox).Checked = True
        Next
    Else
        For i As Integer = 1 To 5
            DirectCast(Me.FindControl("Checkbox" & i), CheckBox).Checked = False
        Next
    End If

End Sub


                        
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