[aljzazy]

Private Sub TextBox1_KeyDown(sender As System.Object, e As System.Windows.Forms.KeyEventArgs) Handles TextBox1.KeyDown
        If e.KeyCode = Keys.Enter Then
            '"ضع هنا الحدث الذي تريده"
        End If
    End Sub

Private Sub BtnSave_Click(sender As System.Object, e As System.EventArgs) Handles BtnSave.Click

  TextBox1_KeyDown(sender, e)
End Sub