Question

My code is this :

SqlConnection scn = new SqlConnection(ClsPublic.GetConnectionString());
                   SqlCommand scm = new SqlCommand("SELECT Name FROM Table WHERE (Blogger = @Blogger)", scn);
                   scm.Parameters.AddWithValue("@Blogger", lblBloger.Text);
                   scn.Open();
                   MyLabel.Text = scm.ExecuteScalar().ToString();
                   scn.Close();

in this line :

lblLastNo.Text = scm.ExecuteScalar().ToString();

Has this error :

Object reference not set to an instance of an object.

or when I using if statement , shows same error

object Blogger= "";
if (Blogger.ToString() != string.Empty)
{
    ....
}

in below code again shows same error .

Answer 1

Most likely scm.ExecuteScalar() is bringing you a null value. You need to test the value returned before using it:

var result = scm.ExecuteScalar();
MyLabel.Text = result == null ? '' : result.ToString();