First hava table called "Items " in your dataset and then paste teh following code in the event which you want.
Here, "ProductId is not null" is the row filter which loads the data view only where the Productid column is not having null values.
DataView fetch = new DataView(dstitems.Tables["Items"], "ProductId is not Null", null, DataViewRowState.CurrentRows);
if (fetch.Count > 0)
// fetch.count will have the no.of rows retrieved from the dataview after the matching
// applying the dataview as the datasource to the dtgmygrid.
dtgmygrid.DataSource = fetch;