Hi,
I'm having a problem with cascading RadDropDownLists where the EnableVirtualScrolling property is enabled. I have three lists that cascade so that each selection filters the available options on the next list. When I first set the screen up, none of the lists had virtual scrolling enabled. It turned out that there was quite a long list for certain combinations of filtering. When the list length exceeded the available space on the page, the user was unable to access the options lower down. After a bit of reading, I discovered the EnableVirtualScrolling property and it seemed to work great. However, I found that the drop-down lists on the lower two tiers of the cascade would only display the first record/row of their available options after a postback from the preceding lists.
Here's my code:
If I remove the [EnableVirtualScrolling="true" DropDownHeight="250px" DropDownWidth="460px"], it all works fine (except that some lists are too long). Am I missing another property or setting somewhere?
Geoff
I'm having a problem with cascading RadDropDownLists where the EnableVirtualScrolling property is enabled. I have three lists that cascade so that each selection filters the available options on the next list. When I first set the screen up, none of the lists had virtual scrolling enabled. It turned out that there was quite a long list for certain combinations of filtering. When the list length exceeded the available space on the page, the user was unable to access the options lower down. After a bit of reading, I discovered the EnableVirtualScrolling property and it seemed to work great. However, I found that the drop-down lists on the lower two tiers of the cascade would only display the first record/row of their available options after a postback from the preceding lists.
Here's my code:
<
telerik:RadDropDownList
ID
=
"DropDownList1"
DataSourceID
=
"SQLDataSource1"
DataValueField
=
"Table1_Id"
DataTextField
=
"Table1_Text"
Width
=
"460px"
EnableVirtualScrolling
=
"true"
DropDownHeight
=
"250px"
DropDownWidth
=
"460px"
AppendDataBoundItems
=
"true"
AutoPostBack
=
"true"
Skin
=
"Metro"
runat
=
"server"
>
</
telerik:RadDropDownList
>
<
telerik:RadDropDownList
ID
=
"DropDownList2"
DataSourceID
=
"SQLDataSource2"
DataTextField
=
"Table2_Id"
DataValueField
=
"Table2_Text"
Width
=
"460px"
EnableVirtualScrolling
=
"true"
DropDownHeight
=
"250px"
DropDownWidth
=
"460px"
AppendDataBoundItems
=
"true"
AutoPostBack
=
"true"
Skin
=
"Metro"
runat
=
"server"
>
</
telerik:RadDropDownList
>
<
telerik:RadDropDownList
ID
=
"DropDownList3"
DataSourceID
=
"SQLDataSource3"
DataTextField
=
"Table3_Id"
DataValueField
=
"Table3_Text"
Width
=
"460px"
EnableVirtualScrolling
=
"true"
DropDownHeight
=
"250px"
DropDownWidth
=
"460px"
AppendDataBoundItems
=
"true"
AutoPostBack
=
"true"
Skin
=
"Metro"
runat
=
"server"
>
</
telerik:RadDropDownList
>
<%-- Data Source for DropDownList1 --%>
<
asp:SqlDataSource
ID
=
"SQLDataSource1"
runat
=
"server"
ConnectionString="<%$ ConnectionStrings:RAMtrack %>"
ProviderName="<%$ ConnectionStrings:RAMtrack.ProviderName %>"
SelectCommand="Select_Table1Data"
SelectCommandType="StoredProcedure">
<
SelectParameters
>
<
asp:SessionParameter
Name
=
"Customer_id"
SessionField
=
"Customer_Id"
Type
=
"Int64"
/>
</
SelectParameters
>
</
asp:SqlDataSource
>
<%-- Data Source for DropDownList2 --%>
<
asp:SqlDataSource
ID
=
"SQLDataSource2"
runat
=
"server"
ConnectionString="<%$ ConnectionStrings:RAMtrack %>"
ProviderName="<%$ ConnectionStrings:RAMtrack.ProviderName %>"
SelectCommand="Select_Table2Data"
SelectCommandType="StoredProcedure"
>
<
SelectParameters
>
<
asp:SessionParameter
Name
=
"Customer_id"
SessionField
=
"Customer_Id"
Type
=
"Int64"
/>
<
asp:ControlParameter
Name
=
"Table1_Id"
ControlID
=
"DropDownList1"
PropertyName
=
"SelectedValue"
DefaultValue
=
"0"
Type
=
"Int64"
/>
</
SelectParameters
>
</
asp:SqlDataSource
>
<%-- Data Source for DropDownList3 --%>
<
asp:SqlDataSource
ID
=
"SQLDataSource3"
runat
=
"server"
ConnectionString="<%$ ConnectionStrings:RAMtrack %>"
ProviderName="<%$ ConnectionStrings:RAMtrack.ProviderName %>"
SelectCommand="Select_Table2Data"
SelectCommandType="StoredProcedure"
>
<
SelectParameters
>
<
asp:SessionParameter
Name
=
"Customer_id"
SessionField
=
"Customer_Id"
Type
=
"Int64"
/>
<
asp:ControlParameter
Name
=
"Table2_Id"
ControlID
=
"DropDownList2"
PropertyName
=
"SelectedValue"
DefaultValue
=
"0"
Type
=
"Int64"
/>
</
SelectParameters
>
</
asp:SqlDataSource
>
<
telerik:RadAjaxManager
ID
=
"RadAjaxManager1"
runat
=
"server"
>
<
AjaxSettings
>
<
telerik:AjaxSetting
AjaxControlID
=
"DropDownList1"
>
<
UpdatedControls
>
<
telerik:AjaxUpdatedControl
ControlID
=
"DropDownList2"
LoadingPanelID
=
"pnl_SystemAffected"
/>
<
telerik:AjaxUpdatedControl
ControlID
=
"DropDownList3"
LoadingPanelID
=
"pnl_SystemAffected"
/>
</
UpdatedControls
>
</
telerik:AjaxSetting
>
<
telerik:AjaxSetting
AjaxControlID
=
"DropDownList2"
>
<
UpdatedControls
>
<
telerik:AjaxUpdatedControl
ControlID
=
"DropDownList3"
LoadingPanelID
=
"pnl_SystemAffected"
/>
</
UpdatedControls
>
</
telerik:AjaxSetting
>
</
AjaxSettings
>
</
telerik:RadAjaxManager
>
If I remove the [EnableVirtualScrolling="true" DropDownHeight="250px" DropDownWidth="460px"], it all works fine (except that some lists are too long). Am I missing another property or setting somewhere?
Geoff