We interested your radgant product but we don't achive to show taski in grand.Also we tried every thing explained in telerik demo cenrter.
In this case how can help you to us.
I have attached the test project.
thanks.
<%@ Page Language="C#" AutoEventWireup="true" CodeBehind="WebForm1.aspx.cs" Inherits="WebApplication3.WebForm1" %>
<%@ Register assembly="Telerik.Web.UI" namespace="Telerik.Web.UI" tagprefix="telerik" %>
<%@ Register assembly="Telerik.Web.UI" namespace="Telerik.Web.UI.Gantt" tagprefix="cc1" %>
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html xmlns='http://www.w3.org/1999/xhtml'>
<head id="Head1" runat="server">
<title>Telerik ASP.NET Example</title>
</head>
<body>
<form id="form1" runat="server">
<telerik:RadScriptManager runat="server" ID="RadScriptManager1" />
<telerik:RadSkinManager ID="RadSkinManager1" runat="server" ShowChooser="false" />
<div class="demo-container no-bg">
<telerik:RadGantt RenderMode="Lightweight" ID="RadGantt1"
runat="server"
DataSourceID="SqlDataSource1"
DependenciesDataSourceID="SqlDataSource2"
ReadOnly="true"
SelectedView="WeekView">
<DataBindings>
<TasksDataBindings IdField="ID" ParentIdField="ParentID" StartField="Start" OrderIdField="OrderID" SummaryField="Summary" ExpandedField="Expanded" EndField="End" TitleField="Title"
PercentCompleteField="PercentComplete" />
<DependenciesDataBindings TypeField="Type" IdField="ID" PredecessorIdField="PredecessorID" SuccessorIdField="SuccessorID" />
</DataBindings>
</telerik:RadGantt>
</div>
<asp:SqlDataSource runat="server" ID="SqlDataSource1" SelectCommand="SELECT * FROM [GanttTasks]" ConnectionString="<%$ ConnectionStrings:FLOWPOTAConnectionString %>"/>
<asp:SqlDataSource runat="server" ID="SqlDataSource2" SelectCommand="SELECT * FROM [GanttDependencies]" ConnectionString="<%$ ConnectionStrings:FLOWPOTAConnectionString %>"/>
</form>
</body>
</html>