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hi
i am trying to add a new row a dataset.. from my win app and then update it
to the db
thru my web service.


private void cmdSubmit_Click(object sender, System.EventArgs e)
{
DataRow dr = dsCity.Tables["city"].NewRow();
dr["cityid"]=3;
dr["cityname"]="newyork";
MessageBox.Show(dsCity.Tables["city"].Rows.Count.ToString());
dsCity.Tables["city"].Rows.Add(dr);
MessageBox.Show(dsCity.Tables["city"].Rows.Count.ToString() + " state=" +
dsCity.Tables["City"].Rows[2].RowState.ToString());
ser=new Service1();
ser.updateCity(dsCity);
}


[Web Method]
public void updateCity(DataSet ds)
{
SqlCommandBuilder cmdBuilder = new SqlCommandBuilder (daCity);
dsCity.Merge(ds); //error
}

however i get an error saying

System.NullReferenceException: Object reference not set to an instance of an
object.

why is that?
thanx

Hi,

On the error line you're calling a method on dsCity. Where is dsCity
defined (and created)? And is the ds parameter definitely not null?

Ian

"drishtik" <> wrote in message
news:...
> hi
> i am trying to add a new row a dataset.. from my win app and then update
it
> to the db
> thru my web service.
>
>
> private void cmdSubmit_Click(object sender, System.EventArgs e)
> {
> DataRow dr = dsCity.Tables["city"].NewRow();
> dr["cityid"]=3;
> dr["cityname"]="newyork";
> MessageBox.Show(dsCity.Tables["city"].Rows.Count.ToString());
> dsCity.Tables["city"].Rows.Add(dr);
> MessageBox.Show(dsCity.Tables["city"].Rows.Count.ToString() + " state="
+
> dsCity.Tables["City"].Rows[2].RowState.ToString());
> ser=new Service1();
> ser.updateCity(dsCity);
> }
>
>
> [Web Method]
> public void updateCity(DataSet ds)
> {
> SqlCommandBuilder cmdBuilder = new SqlCommandBuilder (daCity);
> dsCity.Merge(ds); //error
> }
>
> however i get an error saying
>
> System.NullReferenceException: Object reference not set to an instance of
an
> object.
>
> why is that?
> thanx
>
>
>
>