ð ề 1 và 7:Tính lãi suất… Giao diện: Chương trình: Private Sub cmdXacDinh_Click() Dim SoTienCo As Single, LaiSuat As Single, SoTienCan As Single, SoNamCanGui As Single SoTienCo = Text1 SoTienCan = Text2 LaiSuat = Text3 If SoTienCo >= SoTienCan Then Text4 = "aaaa" Else Do SoTienCo = SoTienCo * (1 + LaiSuat / 100) SoNamCanGui = SoNamCanGui + 1 Loop While SoTienCo <= SoTienCan Text4 = SoNamCanGui Text5 = SoTienCo End If End Sub ð ề 2 & 10:Lấy dữ liệu cổng com.Vẽ ñồ thị Giao diện Chương trình: Private Sub cmdrun_Click() Timer1.Enabled = True End Sub Private Sub cmdStop_Click() Timer1.Enabled = False End Sub Private Sub Form_Load() MSComm1.PortOpen = True End Sub Private Sub Form_Unload(Cancel As Integer) MSComm1.PortOpen = False End Sub Private Sub Timer1_Timer() Static x(), t(), i ReDim Preserve x(i) ' khai bao lai mang ReDim Preserve t(i) ' khai bao lai thoi gian If i = 0 Then Picture1.PSet (Picture1.Height, 0) ' khoi tao diem dau con tro x(i) = MSComm1.Input ' doc gia tri vao tu cong com1 Picture1.Line -(Picture1.Height - x(i) * 100, t(i) * 100) ' ve do thi i = i + 1 End Sub ð ề3:Vẽ y=(ax 2 +b)x. ð ưa ra màn hình ñồ thị &ñiểm cực tiểu Giao diện:Form1 Viết chương trình trong Form2: Private Sub Form_GotFocus() Dim x As Single, y As Double, GTCT As Double, GTCD As Double, y1 As Double Dim i As Integer, a As Single, b As Single 'Form2.BackColor = vbWhite a = Form1.Text1 b = Form1.Text2 've he truc toa do Form2.Line (0, Form2.Height / 2)-(Form2.Width, Form2.Height / 2) Form2.Line (Form2.Width / 2, 0)-(Form2.Width / 2, Form2.Height) 'khac so For i = -3 To 3 CurrentX = (i + 3) * Form2.Width / 6 CurrentY = Form2.Height / 2 + 6 Print i Next For i = -30 To 30 Step 2 CurrentX = Form2.Width / 2 - 6 CurrentY = (i + 30) * Form2.Height / 60 Print i Next ' ve do thi trong khoang -3 den 3 doi voi gia tri cua x va -30 den 30 doi voi gia tri cau y i = 0 For i = 0 To 500 x = -3 + i * 6 / 500 y = a * x ^ 3 + b * x Form2.Line -((x + 3) * Form2.Width / 6, Form2.Height - (y + 30) * Form2.Height / 60) Next 'tinh cuc tri ' y' = 3a*x^2 + b If a * b > 0 Or a = 0 Then Form1.Text3 = "k0 ton tai" Form1.Text4 = "k0 ton tai" Else x = b / (3 * a) GTCT = a * x ^ 3 + b * x x = -b / (3 * a) GTCD = a * x ^ 3 + b * x If GTCT > GTCD Then y1 = GTCT GTCT = GTCD GTCD = y1 End If Form1.Text3 = GTCT Form1.Text4 = GTCD End If End Sub ð ề 4:Nhân ma trận Giao diện: Private Sub cmdcong_Click() Dim i, j, mang1(4, 4) As Single, mang2(4, 4) As Single, mang3(4, 4) As Single ' nhap so lieu vao mang For i = 0 To 3 For j = 0 To 3 mang1(i, j) = Text1(i * 4 + j) mang2(i, j) = Text2(i * 4 + j) Next Next ' thuc hien phep cong For i = 0 To 3 For j = 0 To 3 mang3(i, j) = mang1(i, j) + mang2(i, j) Next Next 'dua ket qua ra man hinh For i = 0 To 3 For j = 0 To 3 Text3(i * 4 + j) = mang3(i, j) Next Next End Sub Private Sub cmdnhan_Click() Dim i, j, mang1(4, 4) As Single, mang2(4, 4) As Single, mang3(4, 4) As Single Dim k ' nhap so lieu vao mang For i = 0 To 3 For j = 0 To 3 mang1(i, j) = Text1(i * 4 + j) mang2(i, j) = Text2(i * 4 + j) Next Next ' thuc hien phap nhan For i = 0 To 3 For j = 0 To 3 For k = 0 To 3 mang3(i, j) = mang3(i, j) + mang1(i, k) * mang2(k, j) Next Next Next 'dua ket qua ra man hinh For i = 0 To 3 For j = 0 To 3 Text3(i * 4 + j) = mang3(i, j) Next Next End Sub ð ề 5:Nhập và phát xung RTS & DTR Dim xung_rts As Integer, xung_dtr As Integer Private Sub cmdphat_Click() Timer1.Interval = Round(1000 / (2 * Text3)) ' dinh thoi gian timer1 tuong ung voi tan so Timer1.Enabled = True ' cho phep timer1 hoat dong xung_rts = Text1 xung_dtr = Text2 End Sub Private Sub Form_Load() MSComm1.PortOpen = True End Sub Private Sub Form_Unload(Cancel As Integer) MSComm1.PortOpen = False End Sub Private Sub Timer1_Timer() Static x As Boolean, y As Boolean ' phat xung ra chan RTS If xung_rts > 0 Then If x = False Then MSComm1.RTSEnable = False ' RTS = 0 x = True Else MSComm1.RTSEnable = True ' RTS = 1 x = False xung_rts = xung_rts - 1 Text4 = xung_rts End If End If ' phat xung ra chan DTR If xung_dtr > 0 Then If y = False Then MSComm1.DTREnable = False ' DTR = 0 y = True Else MSComm1.DTREnable = True ' DTR = 1 y = False xung_dtr = xung_dtr - 1 Text5 = xung_dtr End If End If ' dung timer1 khi da phat het xung If (xung_rts = 0) And (xung_dtr = 0) Then Timer1.Enabled = False ' dung timer1 MsgBox "da phat xong" ' bao da phat xong End If End Sub ð ề 6:Viết chương trình ñèn giao thông Private Sub cmdrun_Click() Timer1.Enabled = True End Sub Private Sub cmdstop_Click() Timer1.Enabled = False ' tat cac den For j = 0 To 11 Label1(j).BackColor = vbBlack Next End Sub Private Sub Form_Load() Dim i For i = 0 To 11 Label1(i).BackColor = vbBlack Next i End Sub Private Sub Timer1_Timer() Dim x As Integer, v As Integer, d As Integer Dim j Static t x = Text1 v = Text2 d = x + v ' thuat giai (tinh theo 1 chu ky thoi gian) ' x v d duong 1 ' d x v duong 2 For j = 0 To 11 Label1(j).BackColor = vbBlack Next ' chon cho duong 1 Select Case t Case Is <= x: Label1(0).BackColor = vbGreen ' xanh Label1(6).BackColor = vbGreen Case Is <= x + v: Label1(1).BackColor = vbYellow ' vang Label1(7).BackColor = vbYellow Case Is <= 2 * (x + v): Label1(2).BackColor = vbRed ' do Label1(8).BackColor = vbRed End Select 'chon cho duong 2 Select Case t Case Is <= d: Label1(5).BackColor = vbRed ' do Label1(11).BackColor = vbRed Case Is <= d + x: Label1(3).BackColor = vbGreen ' xanh Label1(9).BackColor = vbGreen Case Is <= 2 * (x + v): Label1(4).BackColor = vbYellow ' vang Label1(10).BackColor = vbYellow End Select [...]... (Form2.Width / 2, 0) -(Form2.Width / 2, Form2.Height) 'khac so For i = -3 To 3 CurrentX = (i + 3) * Form2.Width / 6 CurrentY = Form2.Height / 2 + 6 Print i Next For i = - 30 To 30 Step 2 CurrentX = Form2.Width / 2 - 6 CurrentY = (i + 30) * Form2.Height / 60 Print i Next ' ve do thi trong khoang -3 den 3 doi voi gia tri cua x va - 30 den 30 doi voi gia tri cau y i =0 For i = 0 To 500 x = -3 + i * 6 / 500 y=a*b*x^2+a*x... gia tri cua x va - 30 den 30 doi voi gia tri cau y i =0 For i = 0 To 500 x = -3 + i * 6 / 500 y=a*b*x^2+a*x Form2.Line -((x + 3) * Form2.Width / 6, Form2.Height - (y + 30) * Form2.Height / 60 ) Next 'tinh cuc tri ' y' = 2abx + a If a * b = 0 Then Form1.Text3 = "k0 ton tai" Else x = -1 / (2 * b) y=a*b*x^2+a*x Form1.Text3 = y End If End Sub ... Then t = 0 '##### doan nay dung de tao ra "dong ho" => k0 can phai them vao Label3 = Time '##################################3 End Sub ðề 8:Vẽ ñồ thị y=ax(bx+c) Private Sub Form_GotFocus() Dim x As Single, y As Double, GTCT As Double, GTCD As Double, y1 As Double Dim i As Integer, a As Single, b As Single 'Form2.BackColor = vbWhite a = Form1.Text1 b = Form1.Text2 've he truc toa do Form2.Line (0, Form2.Height . va - 30 den 30 doi voi gia tri cau y i = 0 For i = 0 To 500 x = -3 + i * 6 / 500 y = a * x ^ 3 + b * x Form2.Line -((x + 3) * Form2.Width / 6, Form2.Height. va - 30 den 30 doi voi gia tri cau y i = 0 For i = 0 To 500 x = -3 + i * 6 / 500 y = a * b * x ^ 2 + a * x Form2.Line -((x + 3) * Form2.Width / 6, Form2.Height