Question

I populated a datagridview from a datatable. How do I read from the datagridview when the application is running?

Answer 1

how did you populate it? is the DataSource something useful like a BindlingList? If it is then something like:

BindingSource bindingSource = this.dataGridView1.DataSource as BindingSource; //substitute your business object type for T  T entity = bindingSource.Current as T; 

would get you the entity bound to the row.

Otherwise there is always the datagridview.Columns[n].Cells[n].Value but really I’d look at using the objects in the DataSource

Edit: Ah… a datatable… righto:

 var table = dataGridView1.DataSource as DataTable;   foreach(DataRow row in table.Rows)  {      foreach(DataColumn column in table.Columns)      {          Console.WriteLine(row[column]);      }  }