Using DevExpress Gridview in asp.net

<dx:ASPxGridView ID="gvSearchPTWNo" runat="server" Width="98%" OnRowCommand="gvCertificate_RowCommand"                     KeyFieldName="ID">                     <Columns>                         <dx:GridViewDataColumn Caption="Asset Name" FieldName="AssetNames" VisibleIndex="0">                         </dx:GridViewDataColumn>                         <dx:GridViewDataColumn Caption="Section Name" FieldName="SectionNames" VisibleIndex="1">                         </dx:GridViewDataColumn>                         <dx:GridViewDataColumn Caption="PTW No." FieldName="CertNums" VisibleIndex="2">                         </dx:GridViewDataColumn>                         <dx:GridViewDataColumn Caption="Work Location" FieldName="WorkLocation" VisibleIndex="3">                         </dx:GridViewDataColumn>                         <dx:GridViewDataColumn Caption="Select">                             <DataItemTemplate>                                 <asp:LinkButton ID="lbtnSelect" runat="server" Text="Select" CommandName="Select"                                     CommandArgument='<%# Eval("CertID") %>'></asp:LinkButton>                             </DataItemTemplate>                         </dx:GridViewDataColumn>                         <dx:GridViewDataColumn Caption="Section ID" FieldName="SectionID" Visible="false">                         </dx:GridViewDataColumn>                           <dx:GridViewDataColumn Caption="Asset ID" FieldName="AssetID" Visible="false">                         </dx:GridViewDataColumn>                          <dx:GridViewDataColumn Caption="Asset ID" FieldName="CertiStatus" Visible="false">                         </dx:GridViewDataColumn>                          <dx:GridViewDataColumn Caption="Cert Stage" FieldName="CertStages" Visible="false">                         </dx:GridViewDataColumn>                     </Columns>                 </dx:ASPxGridView>

protected void gvCertificate_RowCommand(object sender, DevExpress.Web.ASPxGridView.ASPxGridViewRowCommandEventArgs e)         {             string commandname = e.CommandArgs.CommandName;             int visibleIndex = Convert.ToInt32(e.VisibleIndex);             if (commandname == "Select")             {                 var objVal = gvSearchPTWNo.GetRowValues(visibleIndex, "CertNum");                 var objVal1 = gvSearchPTWNo.GetRowValues(visibleIndex, "SectionName");                 var objVal2 = gvSearchPTWNo.GetRowValues(visibleIndex, "AssetName");                 var objSecId = gvSearchPTWNo.GetRowValues(visibleIndex, "SectionID");                 var objAssetId = gvSearchPTWNo.GetRowValues(visibleIndex, "AssetID");                 var objCertStatus = gvSearchPTWNo.GetRowValues(visibleIndex, "CertStatus");                 var objCertStage = gvSearchPTWNo.GetRowValues(visibleIndex, "CertStage");                                  if (visibleIndex >= 0)                 {                     if (VisibleCertificate == 1)                     {                         TextBox txtParent = (TextBox)Parent.FindControl("txtPTWno");                         DropDownList ddlAsset_parent = (DropDownList)Parent.FindControl("ddlAsset");                         UserControl.DeptSections ddlSections_parent = (UserControl.DeptSections)Parent.FindControl("usercontrol_sections");                         ddlSections_parent.bindSectionsAndDepts(Convert.ToInt32(objAssetId.ToString()), Convert.ToInt32(objSecId.ToString()));                         //UserControl.DeptSections ddlSections_parent;                         TextBox txtSections = (TextBox)ddlSections_parent.FindControl("txtSections");                         txtSections.Attributes.Add("SectionId", objSecId.ToString());                         //txtSections.Text = objVal1.ToString();                         ddlAsset_parent.Items.RemoveAt(0);                         ddlAsset_parent.Items.FindByValue(objAssetId.ToString()).Selected = true;                         txtParent.Text = objVal.ToString();                     }                     else                     {                                                 ASPxGridView grvCertificate_parentUctrl = (ASPxGridView)Parent.FindControl("gvCertificates");                         grvCertificate_parentUctrl.DataSource = GVCertificate(objVal.ToString(), objCertStatus.ToString(), objCertStage.ToString());                         grvCertificate_parentUctrl.DataBind();                                             }                 }             }         }

A primary key field specified via the KeyFieldName property is not found in the underlying data source. Make sure the field name is spelled correctly. Pay attention to the character case.

--For this issue we will set the KeyFieldName property in devexpress gridview,whatever we bind the data from database,we will check the field name perfectly...