web form gridview control

Question

In a vb.net 2010 web form application there is the following line of code in a gridview control. ' '<%# Eval(schoolnum) %>' '<%# Eval(milestone_code) %>' '<%# Eval(stulink) %>' '<%# Eval(HOMELNGCOR) %>' '<%# Eval(semester) %>'); style=color:Blue><%#Eval(STUDENTNAME)%> When the user clicks on this link the user is directed to some javascript code called GetStudentLetterTemplate. Once in the javascript function I want to display an error message to the user saying basically saying there is duplicate data in the database. I want to then want the function to 'return' so no processing by the user can occur. Note: the duplicate data is created by the user by them using vendor software that I have no control over. The sql that I want to use is something like the following: #Region Public Shared Function GetDupScoolYear _ Public Shared Function GetDupScoolYear() As DataTable Dim _dt As DataTable = New DataTable() Dim Query As String = SELECT [personID]value count(*) as Count FROM [t].[dbo].[CustomStudent] where attributeID = 2775 and [personID] = 97366 group by [personID]value Using con As SqlConnection = DB.OpenConnection() Using da As SqlDataAdapter = New SqlDataAdapter(Query con) Try da.Fill(_dt) Catch ex As Exception End Try End Using End Using Return _dt End Function #End Region Thus can you tell me or show me what I can do to solve the problem? Is there possibly someway that I could call the code I listed above or similar code before the java script code is called? Basically would you tell me what I can do to solve this issue?

dc · Answer

Gridview thank you! However I have the following additional questions: 1. Am I suppose to use any/all of the following for what you are suggesting; onpageindexchanging=gvPerson_PageIndexChanging onrowcancelingedit=gvPerson_RowCancelingEdit onrowdatabound=gvPerson_RowDataBoundonrowdeleting=gvPerson_RowDeleting onrowediting=gvPerson_RowEditingonrowupdating=gvPerson_RowUpdating onsorting=gvPerson_Sorting Ifso which calls am I trying to use? 2. If I am not using the code you suggested above what part of the gridview code that you showed me would I be using? 3. Of whatever item(s) you suggested would you show methe code I should be using in the individual objects that would be called?

dc · Answer

Thanks for your answer so far! Would you show me the code and/or point me to urls (links) that will tell me how to accomplish the following tasks: 1.Call an ajax page. How do you setup an ajax page? 2.pass parameters to that ajax page and return the result from ajax page?

Midhun T P · Answer

Hi You may use ajax method for that. On the javascript function call an ajax page and pass parameters to that page and return the result from ajax and accordingly give message.

Ajay Malik · Answer

try this code gvPerson runat= server AutoGenerateColumns= False BackColor= White BorderColor= #3366CC BorderStyle= None BorderWidth= 1px CellPadding= 4 onpageindexchanging= gvPerson_PageIndexChanging onrowcancelingedit= gvPerson_RowCancelingEdit onrowdatabound= gvPerson_RowDataBound onrowdeleting= gvPerson_RowDeleting onrowediting= gvPerson_RowEditing onrowupdating= gvPerson_RowUpdating onsorting= gvPerson_Sorting > White ForeColor= #003399 /> True /> True /> PersonID HeaderText= PersonID ReadOnly= True SortExpression= PersonID /> LastName SortExpression= LastName > TextBox1 runat= server Text= ' ' > Label1 runat= server Text= ' ' > FirstName SortExpression= FirstName > TextBox2 runat= server Text= ' ' > Label2 runat= server Text= ' ' > #99CCCC ForeColor= #003399 /> #99CCCC ForeColor= #003399 HorizontalAlign= Left /> #009999 Font-Bold= True ForeColor= #CCFF99 /> #003399 Font-Bold= True ForeColor= #CCCCFF /> lbtnAdd runat= server onclick= lbtnAdd_Click >AddNew pnlAdd runat= server Visible= False > Lastname: tbLastName runat= server > Firstname: tbFirstName runat= server > lbtnSubmit runat= server onclick= lbtnSubmit_Click >Submit lbtnCancel runat= server onclick= lbtnCancel_Click >Cancel