What is code for showing data in both textboxes and listbox

Question

Hi I am working on a new windows form project. I am using dataGridVIew and I want to be able to add items, update and delete. I have configured -sql correctly and I am to add data and it's showing in dataGridView but when I click on the row to select it since am using row header mouse click event, it's not show the items in my text boxes and list box. Please any help ?