使用级联组合框

我正在使用Telerik radGrid显示数据，包括地址。我希望能够插入新的或编辑现有的地址。为此，我希望使用将预先填充下一个的Cascading组合框，即country_onselectedindexchanged填充Province/State等。使用级联组合框

我的问题是，无论何时点击国家/地区，我都可以看到我的省份/状态组合被填充，但发生回发并且我的Grid_itemdatabound事件触发，并且初始数据再次被重新填充。

我在Telerik网站上有一个帐户，但上次我发布了一个问题，需要一个星期才能得到回复。

<telerik:RadGrid ID="RecipientsGrid" runat="server" AutoGenerateColumns="false" EnableViewState="true" PageSize="5" 
        AllowFilteringByColumn="true" AllowPaging="true" AllowSorting="True"> 
      <ClientSettings EnablePostBackOnRowClick="true"> 
       <Selecting AllowRowSelect="true" /> 
      </ClientSettings> 
      <MasterTableView CommandItemDisplay="Bottom" DataKeyNames="RecipientOrganizationID" EditMode="EditForms" > 
       <EditFormSettings EditFormType="Template"> 
       <FormTemplate> 
            <telerik:RadComboBox ID="CountryCombo" runat="server" DataTextField="CountryName" DataValueField="CountryID" 
                 OnSelectedIndexChanged="CountryCombo_SelectedIndexChanged" AutoPostBack="true"> 
            </telerik:RadComboBox> 
            <telerik:RadComboBox ID="ProvinceCombo" runat="server" Width="325" EnableLoadonDemand="true" OnSelectedIndexChanged="ProvinceCombo_SelectedIndexChanged" AutoPostBack="true" > 
            </telerik:RadComboBox> 
       </FormTemplate> 
      </EditFormSettings> 

      </MasterTableView> 

     </telerik:RadGrid>

Private Sub RecipientsGrid_NeedDataSource(sender As Object, e As Telerik.Web.UI.GridNeedDataSourceEventArgs) Handles RecipientsGrid.NeedDataSource 

       Dim ctx As New DataEntities 
       RecipientsGrid.DataSource = ctx.RecipientOrganizations.ToList 

       AddOrganizationButton.Visible = False 
       RecipientOrganizationComboBox.Visible = False 

    End Sub 

Private Sub RecipientsGrid_ItemDataBound(sender As Object, e As Telerik.Web.UI.GridItemEventArgs) Handles RecipientsGrid.ItemDataBound 

     If TypeOf e.Item Is GridEditableItem AndAlso e.Item.IsInEditMode Then 
      Dim editedItem As GridEditableItem = TryCast(e.Item, GridEditableItem) 

      If e.Item.OwnerTableView.IsItemInserted Then 

       Dim CountryCombo As RadComboBox = TryCast(editedItem.FindControl("CountryCombo"), RadComboBox) 
       Dim ProvinceCombo As RadComboBox = TryCast(editedItem.FindControl("ProvinceCombo"), RadComboBox) 
       Dim CityCombo As RadComboBox = TryCast(editedItem.FindControl("CityCombo"), RadComboBox) 

       LoadCountries(CountryCombo) 

      Else 

      End If 

     End If 

    End Sub 

    Protected Sub CountryCombo_SelectedIndexChanged(ByVal sender As Object, ByVal e As RadComboBoxSelectedIndexChangedEventArgs) 

     Dim CountryCombo As RadComboBox = DirectCast(sender, RadComboBox) 
     Dim editedItem As GridEditableItem = DirectCast(TryCast(sender, RadComboBox).NamingContainer, GridEditableItem) 
     Dim ProvinceCombo As RadComboBox = DirectCast(editedItem.FindControl("ProvinceCombo"), RadComboBox) 

     LoadProvinces(e.Value, ProvinceCombo) 

    End Sub 

    Protected Sub ProvinceCombo_SelectedIndexChanged(ByVal sender As Object, ByVal e As RadComboBoxSelectedIndexChangedEventArgs) 

     Dim ProvinceCombo As RadComboBox = DirectCast(sender, RadComboBox) 
     Dim editedItem As GridEditableItem = DirectCast(TryCast(sender, RadComboBox).NamingContainer, GridEditableItem) 
     Dim CityCombo As RadComboBox = DirectCast(editedItem.FindControl("CityCombo"), RadComboBox) 

     LoadCities(e.Value, CityCombo) 

    End Sub 

    Protected Sub LoadCountries(ByVal Control As RadComboBox) 

     Using context As New DataEntities 
      With Control 
       .DataValueField = "CountryId" 
       .DataTextField = "CountryName" 
       .DataSource = context.Countries.OrderBy(Function(x) x.displayOrder).ToList 
      End With 
      Control.Width = Unit.Pixel(320) 
      Control.DataBind() 
     End Using 

    End Sub 

    Protected Sub LoadProvinces(ByVal countryID As Integer, ByVal Control As RadComboBox) 

     Using context As New DataEntities 
      With Control 
       .DataValueField = "ProvinceId" 
       .DataTextField = "NameEnglish" 
       .DataSource = context.Provinces.Where(Function(x) x.CountryId = countryID).OrderBy(Function(x) x.NameEnglish).ToList 
      End With 
      Control.Width = Unit.Pixel(320) 
      Control.DataBind() 
     End Using 

    End Sub 

    Protected Sub LoadCities(ByVal ProvinceId As Integer, ByVal Control As RadComboBox) 

     Using context As New DataEntities 
      With Control 
       .DataValueField = "CityId" 
       .DataTextField = "CityName" 
       .DataSource = context.Cities.Where(Function(x) x.ProvinceID = ProvinceId).OrderBy(Function(x) x.CityName).ToList 
      End With 
      Control.Width = Unit.Pixel(320) 
      Control.DataBind() 
     End Using 

    End Sub 
    Public Sub SetComboBoxDefault(ByVal FindItemByValue As Integer, ByVal Control As RadComboBox, ByVal DisplayText As String) 

     Dim ComboBoxItem As RadComboBoxItem 

     If FindItemByValue > 0 Then 
      ComboBoxItem = Control.FindItemByValue(FindItemByValue) 
      If ComboBoxItem IsNot Nothing Then 
       ComboBoxItem.Selected = True 
      Else 
       Control.Items.Insert(0, New RadComboBoxItem("-- Please select a " & DisplayText & " --", String.Empty)) 
      End If 
     Else 
      Control.Items.Insert(0, New RadComboBoxItem("-- Please select a " & DisplayText & " --", String.Empty)) 
     End If 

    End Sub

来源

2012-10-16 Tim Cadieux

张贴这在这里，因为我不相信我有足够的代表处发表评论。通常，当我遇到这个问题时，这是因为我的Page_Load中的RadComboBox上有某种绑定事件没有包含在If Not IsPostBack中。尝试这样的：

Sub Page_Load 
    If Not IsPostBack 
     RadComboBox.DataSource = foo; 
     RadComboBox.DataBind(); 
    End If 
End Sub

希望这会有所帮助。

来源

2013-04-02 14:24:31 dstepan

使用级联组合框

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