"Object reference not set to an instance of an object.".....er ror

[piyumi80]

hi,
i write the following code to get a specific data row from the data set.but it generates the
"Object reference not set to an instance of an object.".....er ror
private void showClientListF orUser()
{
string[] fkeys = new string[2];

fkeys[0] = txtUserName.Tex t;
fkeys[1] = txtUserCompanyN umber.Text;

DataSet ds = new DataSet();
DataRow dr = null;

for (int i = 0; i < dsMain.Tables["UserClient "].Rows.Count; i++)
{
dr[i] = dsMain.Tables["UserClient "].Select("UserID ="+"'"+fkeys[0]+"'"+ "and CompNo= " + fkeys[1]);

// dr = ds.Tables[0].Rows[i];
lvwClientsForUs er.Items.Add(Co nvert.ToString( dr["CompNo"]));
lvwClientsForUs er.Items[i].SubItems.Add(C onvert.ToString (dr["ClientNo"]));
lvwClientsForUs er.Items[i].SubItems.Add(C onvert.ToString (dr["CNAME"]));
}
}
if anyone can help me to correct this error?

[Shashi Sadasivan]

for starters,
Please put your code between the [code] Tags
Second, your probably have about 20 lines there....which line and which object threw that error is unknown !!

PLease state them clearly and it woiuld be helpful

cheers

[piyumi80]

for starters,
Please put your code between the [code] Tags
Second, your probably have about 20 lines there....which line and which object threw that error is unknown !!

PLease state them clearly and it woiuld be helpful

cheers

dr[i] = dsMain.Tables["UserClient "].Select("UserID ="+"'"+fkeys[0]+"'"+ "and CompNo=" + fkeys[1]);//this line throws the error

[Strika Amaru]

Firstly:

     private void showClientListForUser()
        {
            string[] fkeys = new string[2];
 
            fkeys[0] = txtUserName.Text;
            fkeys[1] = txtUserCompanyNumber.Text;
 
            DataSet ds = new DataSet();
            DataRow dr = null;
 
            for (int i = 0; i < dsMain.Tables["UserClient"].Rows.Count; i++)
            {
                dr[i] = dsMain.Tables["UserClient"].Select("UserID="+"'"+fkeys[0]+"'"+ "and CompNo= " + fkeys[1]); // err
 
              //  dr = ds.Tables[0].Rows[i];
                lvwClientsForUser.Items.Add(Convert.ToString(dr["CompNo"]));
                lvwClientsForUser.Items[i].SubItems.Add(Convert.ToString(dr["ClientNo"]));
                lvwClientsForUser.Items[i].SubItems.Add(Convert.ToString(dr["CNAME"]));
            }
        }

Secondly: This is a pretty weird one; at first glance, it would seem that dsMain.Tables["UserClient "] doesn't exist, so Select gets called on a null reference; but within the for, .Rows.Count gets called without any problems. If I were in your place, I'd run a debug session to figure out exactly what's going on in there.

[Shashi Sadasivan]

that is becuase before the for loop u declared dr = null
and in the first statement in your for loop you are trying to assign dr[i]
when dr itself is null, dr[i] will definitely throw errors :)

cheers

[Plater]

They're right, you never assign anything to your DataRow dr.
So Instead of:

dr[i]=
 

Try using:

dsMain.Tables["UserClient"].Rows[i]=