For the following scenario
this.dataGridViewPurDetails.DataSource = this.purchaseDetailBindingSource;
// purchaseDetailBindingSource
// this.purchaseDetailBindingSource.DataMember = "PurchaseDetail";
this.purchaseDetailBindingSource.DataSource = this.tVDataSet;
This Solution Worked
//Clear All the rows from the datagridview
BindingSource DT = (BindingSource)dataGridViewPurDetails.DataSource;
if (DT != null)
((TVDataSet)DT.DataSource).PurchaseDetail.Clear();