Dropdown list showing error with this code

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Hi, All

Here i try to show two columns in dropdownlist, when i retrieve the data from DB showing Error Object Reference error !

My Code IS:

C#

DataTable Dtab_1 = new DataTable();
            Dtab_1 = DbCon.GetData("select ReasonCodeC +' /  '+ReasonNameC as ReasonD from reason");
            ddlresoncode.DataSource = Dtab_1;
            ddlresoncode.DataTextField = "ReasonD";
            ddlresoncode.DataBind();
            DataTable Dtab_2 = new DataTable();
            Dtab_2 = DbCon.GetData("select r.ReasonCodeC+' / '+r.ReasonNameC as reasonD from reason as r inner join holiday as h on r.ReasonCodeC=h.ReasonCodeC where h.HolidayNameC='" + strCmd + "'");
            ddlresoncode.Items.FindByText(Dtab_2.Rows[0]["reasonD"].ToString()).Selected = true; // Here i Got Error!

Posted 11-Sep-14 1:06am

prasanna.raj

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Sinisa Hajnal · Answer 1 · 2014-09-11T01:51:00

Solution 1

The error is probably caused by FindByText returning NULL and you not checking it before using it.
Always check for object existence and validity before using it.

Object sel = ddlresoncode.Items.FindByText(Dtab_2.Rows[0]["reasonD"].ToString());
if ( sel != null)
sel.Selected = True
else // do something else
return;

Posted 11-Sep-14 1:51am

Sinisa Hajnal

Comments

prasanna.raj 11-Sep-14 8:11am

i have confuse in that part, i passed value by datatable in dropdown but why its return null....

Sinisa Hajnal 11-Sep-14 8:17am

Because the control is nested (find the exact html from the page)? Because your inner join didn't return anything (so that rows[0] actually fails and not FindControl)? Until you find exactly what is going on, there is nothing more I can do.