My code :
<telerik:RadGrid ID="RadGridOrder" ShowStatusBar="true" runat="server" OnNeedDataSource="RadGridOrder_NeedDataSource"
OnItemDataBound="RadGridOrder_ItemDataBound" Width="100%" AutoGenerateColumns="False"
AllowMultiRowSelection="False" GridLines="None" AllowAutomaticUpdates="True"
OnItemUpdated="RadGridOrder_ItemUpdated" EnableViewState="true" OnEditCommand="RadGridOrder_ItemEdit"
OnDataBound="RadGridOrder_DataBound" OnItemCommand="RadGridOrder_ItemCommand">
<ClientSettings EnableRowHoverStyle="true" AllowColumnsReorder="false" ReorderColumnsOnClient="true">
<Selecting AllowRowSelect="True" />
<Resizing EnableRealTimeResize="false" ResizeGridOnColumnResize="false" AllowColumnResize="false">
</Resizing>
</ClientSettings>
<MasterTableView Width="100%" DataKeyNames="OrderSubOrderID" ExpandCollapseColumn-ButtonType="ImageButton"
EditMode="InPlace" ExpandCollapseColumn-CollapseImageUrl="Img/minus.png" ExpandCollapseColumn-ExpandImageUrl="Img/Plus.png">
<DetailTables>
<telerik:GridTableView ShowHeadersWhenNoRecords="false" HorizontalAlign="Right" BorderWidth="1px"
EnableNoRecordsTemplate="" Width="80%" runat="server">
<ParentTableRelation>
<telerik:GridRelationFields DetailKeyField="OrderSubOrderID" MasterKeyField="OrderSubOrderID" />
</ParentTableRelation>
<Columns>
<telerik:GridBoundColumn HeaderText="ShippingStatus" DataField="Status" UniqueName="ShippingStatus">
</telerik:GridBoundColumn>
<telerik:GridBoundColumn HeaderText="textShipDate" DataField="ShippedOn" DataFormatString="{0:MM/dd/yyyy}"
UniqueName="Timestamp">
</telerik:GridBoundColumn>
<telerik:GridBoundColumn HeaderText="Quantitystr" DataField="Quantity" UniqueName="quantity">
</telerik:GridBoundColumn>
</Columns>
</telerik:GridTableView>
</DetailTables>
<Columns>
<telerik:GridEditCommandColumn ButtonType="ImageButton" ItemStyle-Width="25" HeaderStyle-Width="25" />
<telerik:GridTemplateColumn HeaderText="ExternalItemstr" UniqueName="SKU">
<ItemTemplate>
<%#Eval("SKU")%>
</ItemTemplate>
<EditItemTemplate>
<asp:TextBox ID="txtCouponCode" runat="server" Text='<%#Eval("SKU")%>'
Width="95" />
</EditItemTemplate>
</telerik:GridTemplateColumn>
<telerik:GridBoundColumn HeaderText="txtQuantityOrdered" DataField="Quantity" UniqueName="OrderedQuantity">
</telerik:GridBoundColumn>
<telerik:GridBoundColumn HeaderText="txtQuantityShipped" DataField="Shipped
Quantity" UniqueName="ShippedQuantity">
</telerik:GridBoundColumn>
</Columns>
</MasterTableView>
<ClientSettings ReorderColumnsOnClient="True" AllowDragToGroup="True" AllowColumnsReorder="True">
</ClientSettings>
</telerik:RadGrid>
Screen Short: please check attachment.
Please let me know if any one know solution.
<telerik:RadGrid ID="RadGridOrder" ShowStatusBar="true" runat="server" OnNeedDataSource="RadGridOrder_NeedDataSource"
OnItemDataBound="RadGridOrder_ItemDataBound" Width="100%" AutoGenerateColumns="False"
AllowMultiRowSelection="False" GridLines="None" AllowAutomaticUpdates="True"
OnItemUpdated="RadGridOrder_ItemUpdated" EnableViewState="true" OnEditCommand="RadGridOrder_ItemEdit"
OnDataBound="RadGridOrder_DataBound" OnItemCommand="RadGridOrder_ItemCommand">
<ClientSettings EnableRowHoverStyle="true" AllowColumnsReorder="false" ReorderColumnsOnClient="true">
<Selecting AllowRowSelect="True" />
<Resizing EnableRealTimeResize="false" ResizeGridOnColumnResize="false" AllowColumnResize="false">
</Resizing>
</ClientSettings>
<MasterTableView Width="100%" DataKeyNames="OrderSubOrderID" ExpandCollapseColumn-ButtonType="ImageButton"
EditMode="InPlace" ExpandCollapseColumn-CollapseImageUrl="Img/minus.png" ExpandCollapseColumn-ExpandImageUrl="Img/Plus.png">
<DetailTables>
<telerik:GridTableView ShowHeadersWhenNoRecords="false" HorizontalAlign="Right" BorderWidth="1px"
EnableNoRecordsTemplate="" Width="80%" runat="server">
<ParentTableRelation>
<telerik:GridRelationFields DetailKeyField="OrderSubOrderID" MasterKeyField="OrderSubOrderID" />
</ParentTableRelation>
<Columns>
<telerik:GridBoundColumn HeaderText="ShippingStatus" DataField="Status" UniqueName="ShippingStatus">
</telerik:GridBoundColumn>
<telerik:GridBoundColumn HeaderText="textShipDate" DataField="ShippedOn" DataFormatString="{0:MM/dd/yyyy}"
UniqueName="Timestamp">
</telerik:GridBoundColumn>
<telerik:GridBoundColumn HeaderText="Quantitystr" DataField="Quantity" UniqueName="quantity">
</telerik:GridBoundColumn>
</Columns>
</telerik:GridTableView>
</DetailTables>
<Columns>
<telerik:GridEditCommandColumn ButtonType="ImageButton" ItemStyle-Width="25" HeaderStyle-Width="25" />
<telerik:GridTemplateColumn HeaderText="ExternalItemstr" UniqueName="SKU">
<ItemTemplate>
<%#Eval("SKU")%>
</ItemTemplate>
<EditItemTemplate>
<asp:TextBox ID="txtCouponCode" runat="server" Text='<%#Eval("SKU")%>'
Width="95" />
</EditItemTemplate>
</telerik:GridTemplateColumn>
<telerik:GridBoundColumn HeaderText="txtQuantityOrdered" DataField="Quantity" UniqueName="OrderedQuantity">
</telerik:GridBoundColumn>
<telerik:GridBoundColumn HeaderText="txtQuantityShipped" DataField="Shipped
Quantity" UniqueName="ShippedQuantity">
</telerik:GridBoundColumn>
</Columns>
</MasterTableView>
<ClientSettings ReorderColumnsOnClient="True" AllowDragToGroup="True" AllowColumnsReorder="True">
</ClientSettings>
</telerik:RadGrid>
Screen Short: please check attachment.
Please let me know if any one know solution.