CODEWITHSUNDEEP
c#asp.netgridview
Sudhir Somu
Sudhir Somu

Reputation: 71

Find Control returns Null Exception

I am having an asp .Net page where i have a labe named rowId

      protected void testResultsGridView_onRowUpdating(object sender, GridViewUpdateEventArgs e)
    {
        string str = string.Empty;
        GridViewRow row = testResultsGridView.Rows[e.RowIndex];
        Int32 id = Int32.Parse(((Label)row.FindControl("rowId")).Text);
        String Cause = ((DropDownList)row.FindControl("Cause")).SelectedValue;
        String comment = ((TextBox)row.FindControl("comment")).Text;
        String check = ((TextBox)row.FindControl("check")).Text;
        String reRunStatus = ((DropDownList)row.FindControl("Status")).SelectedValue;
        String subCategory = ((DropDownList)row.FindControl("Category")).SelectedValue;


        foreach (GridViewRow gvrow in testResultsGridView.Rows)
        {
            CheckBox chk = (CheckBox)gvrow.FindControl("cbSelect");
            if (chk != null && chk.Checked)
            {
                 id = Int32.Parse(((Label)gvrow.FindControl("rowId")).Text); ;

                UpdateTestCase(id, rootCause, subCategory, comment, RTC, reRunStatus);

            }
        }
        testResultsGridView.EditIndex = -1;
        BindData();
    }

In this case first find control of rowId return values and second one inside selected scheckbox returns null. I am not even adding any control dynamically. What might be the reason?

Upvotes: 1

Views: 939

Answers (1)

Adil
Adil

Reputation: 148110

GridView not only have DataRows but has other row types like header, foooter. Your control are in DataRow type. You need to check if the row where you are trying to find rowId is a DataRow as there are other row types which would not have conntrol with id rowId You can find more about RowType here. You have to find control where RowType is DataRow.

if(gvrow.RowType == DataControlRowType.DataRow)

Why it works for first time

It works for first time because the event onRowUpdating is fired on row having type DataRow.

Why it does not work for second time

For second time you are iterating the Rows of GridView which have other row types as well. If you debug the code you will see you will get null when RowType is not DataRow.

You code would be

foreach (GridViewRow gvrow in testResultsGridView.Rows)
{
   if(gvrow.RowType == DataControlRowType.DataRow)
   {
        CheckBox chk = (CheckBox)gvrow.FindControl("cbSelect");
        if (chk != null && chk.Checked)
        {
             id = Int32.Parse(((Label)gvrow.FindControl("rowId")).Text); ;

            UpdateTestCase(id, rootCause, subCategory, comment, RTC, reRunStatus);

        }
    }
}

Upvotes: 2

Related Questions