Sharepoint 2010 - bind listview error message :Object reference not set to an instance of an object

Question

I have an application page which retieve data from a stored procedure, my page give me the desired result but I discovrer in log table that this page have an error

 System.NullReferenceException: Object reference not set to an instance of an object.
   at PWC.SharePoint.Common.Layouts.PWC.RejectedReassessments.OnPreRender(EventArgs e)

when I debug I found this error in the line :

this.ReassessmentSelectorDataPager.DataBind();

this is the part of the code, I can't have further details

  protected override void OnPreRender(EventArgs e)
    {
        base.OnPreRender(e);
        this.EnsureChildControls();

        try
        {

            this.ApprovedReassessmentsListView.DataBind();
            BindReassessmentSelectorToControl();
            this.ReassessmentSelectorDataPager.DataBind();
        }
        catch (Exception ex)
        {
            LoggingUtilities.LogToDatabase(PWC_LOG_TYPE.ERROR, ex.Message, ex.ToString(), this.currentWeb.Url, this.currentWeb.CurrentUser.LoginName);
        }
    }

Help please ?

Answer 1

What I understand, When you debug you get Object reference not set to an instance of an object at the data pager control this.ReassessmentSelectorDataPager.DataBind();

This issue occurs if you tried at your code to set data pager ReassessmentSelectorDataPager programmatically to null like this DataPager ReassessmentSelectorDataPager = null; so make sure that it's not set to null at any line in your code.

Also , no need to bind data pager control like this this.ReassessmentSelectorDataPager.DataBind(); it's related to a specific list view that should be defined at PagedControlID property at asp:DataPager tag, so you need to set the data source of this listview then bind it like this

 ListView1.DataSource = fucctionthat will retrive data to list view();
 ListView1.DataBind();