If you want to show the contents of the datagridview by clicking on any cell of the row. then Write this code in the CellContentClick() event of the datagridview
textbox1.text = datagridview1.Rows(e.RowIndex).Cells(0).Value
textbox2.text = datagridview1.Rows(e.RowIndex).Cells(1).Value
(etc)
If you want to show the contents of the datagridview by clicking the header of the row then write this code in the RowHeaderMouseClick event of the datagridview
textbox1.text = datagridview1.Rows(e.RowIndex).Cells(0).Value
textbox2.text = datagridview1.Rows(e.RowIndex).Cells(1).Value
(etc)
Note: textbox1 and textbox2 are only for example. Use your one fields here to get the datagridview contents.