Question

如何用vb画出简易函数图像

Answer 1

用vb画出简易函数图像的操作步骤为：
（1）新建一个工程,新建一个Form1,在上面添加一个picture控件和一个command控件；
（2）选中此控件,右击"复制",在窗体空白处右击"粘贴",在弹出的对话框中选择"是",创建了一个Command控件数组,复制,使窗体上总共出现7个Command控件；
（3）复制代码:
Const Pi = 3.1415926535 '定义圆周率
Dim a, wor
Dim i As Integer
Static Function Loge(X)
Loge = Log(X) / Log(Exp(1))
End Function

'定义用于在Picture1上的一个位置打印字符函数
Private Function PrintWord(X, y, Word As String)
With Picture1
.CurrentX = X
.CurrentY = y
.ForeColor = RGB(0, 0, 255)
End With
Picture1.Print Word
End Function

Private Function DrawDot(Px, Py, Color)
Picture1.PSet (Px, Py), Color
End Function

Sub XY() '建立直角坐标系
Picture1.DrawWidth = 1 '设置线条宽度
Picture1.Cls
'设定用户坐标系，坐标原点在Picture1中心
Picture1.Scale (-10, 10)-(10, -10)
Picture1.Line (-10, 0)-(10, 0), RGB(0, 0, 255)
Picture1.Line -(9.5, 0.5), RGB(0, 0, 255)
Picture1.Line (10, 0)-(9.5, -0.5), RGB(0, 0, 255)
Picture1.ForeColor = RGB(0, 0, 255)

Picture1.Print "X"
'画 X 轴
Picture1.Line (0, -10)-(0, 10), RGB(0, 0, 255)
Picture1.Line -(0.5, 9.5), RGB(0, 0, 255)
Picture1.Line (0, 10)-(-0.5, 9.5), RGB(0, 0, 255)
Picture1.Print "Y"
'画 Y 轴
For lin = -9 To 9
Picture1.Line (lin, 0)-(lin, 0.25)
wor = PrintWord(lin - 0.5, -0.5, Str(lin))
Picture1.Line (0, lin)-(-0.25, lin)
If lin <> 0 Then
wor = PrintWord(-0.9, lin, Str(lin))
End If
Next lin
Picture1.DrawWidth = 2
End Sub

Private Sub Command1_Click(Index As Integer)
Select Case Index
Case 0
For a = -3 To 3 Step Pi / 6000
Dot = DrawDot(a, a ^ 2, RGB(0, 0, 0))
Next a
wor = PrintWord(4, 9, "二次曲线 y=x^2")
Case 1
For a = -9 To 9 Step Pi / 6000
Dot = DrawDot(a, a, RGB(0, 0, 0))
Next a
wor = PrintWord(8, 5, "一次曲线 y=x")
Case 2
For a = -9 To 3 Step Pi / 6000
Dot = DrawDot(a, Exp(a), RGB(0, 0, 0))
Next a
wor = PrintWord(4, 9, "指数曲线 y=e^x")
Case 3
For a = 0.0001 To 9 Step Pi / 6000
Dot = DrawDot(a, Loge(a), RGB(0, 0, 0))
Next a
wor = PrintWord(8, 3, "对数曲线 y=ln x")
Case 4
For a = -10 To 10 Step Pi / 6000
Dot = DrawDot(a, Sin(a), RGB(0, 0, 0))
Next a
wor = PrintWord(-5, 2, "正弦曲线 y=sin x")
Case 5
For a = -10 To 10 Step Pi / 6000
Dot = DrawDot(a, Cos(a), RGB(0, 0, 0))
Next a
wor = PrintWord(-9, 2, "余弦曲线 y=cos x")
Case 6
XY
End Select
End Sub
Private Sub Form_Load()
Me.Caption = "数学函数作图?quot;"
Me.Show
Me.AutoRedraw = True
Picture1.AutoRedraw = True
Command1(0).Caption = "二次曲线"
Command1(1).Caption = "一次曲线"
Command1(2).Caption = "指数曲线"
Command1(3).Caption = "对数曲线"
Command1(4).Caption = "正弦曲线"
Command1(5).Caption = "余弦曲线"
Command1(6).Caption = "清空"
XY
End Sub

Private Sub Form_Resize()
Picture1.Width = Me.Width * 0.94
Picture1.Height = Me.Height - (Command1(0).Height * 4 + 100)

Command1(0).Top = Me.Height - (Command1(0).Height * 2.5 + 100)
Command1(0).Left = Me.Width * 0.01

For i = 1 To 6
Command1(i).Top = Me.Height - (Command1(0).Height * 2.5 + 100)
Command1(i).Left = Command1(i - 1).Left + 1000
Next
XY
End Sub

Answer 2

第一步,新建一个工程,新建一个Form1,在上面添加一个picture控件和一个command控件,然后选中此控件,右击"复制",在窗体空白处右击"粘贴",在弹出的对话框中选择"是",创建了一个Command控件数组,复制,使窗体上总共出现7个Command控件,然后复制代码:
Const Pi = 3.1415926535 '定义圆周率
Dim a, wor
Dim i As Integer
Static Function Loge(X)
Loge = Log(X) / Log(Exp(1))
End Function

'定义用于在Picture1上的一个位置打印字符函数
Private Function PrintWord(X, y, Word As String)
With Picture1
.CurrentX = X
.CurrentY = y
.ForeColor = RGB(0, 0, 255)
End With
Picture1.Print Word
End Function

Private Function DrawDot(Px, Py, Color)
Picture1.PSet (Px, Py), Color
End Function

Sub XY() '建立直角坐标系
Picture1.DrawWidth = 1 '设置线条宽度
Picture1.Cls
'设定用户坐标系，坐标原点在Picture1中心
Picture1.Scale (-10, 10)-(10, -10)
Picture1.Line (-10, 0)-(10, 0), RGB(0, 0, 255)
Picture1.Line -(9.5, 0.5), RGB(0, 0, 255)
Picture1.Line (10, 0)-(9.5, -0.5), RGB(0, 0, 255)
Picture1.ForeColor = RGB(0, 0, 255)

Picture1.Print "X"
'画 X 轴
Picture1.Line (0, -10)-(0, 10), RGB(0, 0, 255)
Picture1.Line -(0.5, 9.5), RGB(0, 0, 255)
Picture1.Line (0, 10)-(-0.5, 9.5), RGB(0, 0, 255)
Picture1.Print "Y"
'画 Y 轴
For lin = -9 To 9
Picture1.Line (lin, 0)-(lin, 0.25)
wor = PrintWord(lin - 0.5, -0.5, Str(lin))
Picture1.Line (0, lin)-(-0.25, lin)
If lin <> 0 Then
wor = PrintWord(-0.9, lin, Str(lin))
End If
Next lin
Picture1.DrawWidth = 2
End Sub

Private Sub Command1_Click(Index As Integer)
Select Case Index
Case 0
For a = -3 To 3 Step Pi / 6000
Dot = DrawDot(a, a ^ 2, RGB(0, 0, 0))
Next a
wor = PrintWord(4, 9, "二次曲线 y=x^2")
Case 1
For a = -9 To 9 Step Pi / 6000
Dot = DrawDot(a, a, RGB(0, 0, 0))
Next a
wor = PrintWord(8, 5, "一次曲线 y=x")
Case 2
For a = -9 To 3 Step Pi / 6000
Dot = DrawDot(a, Exp(a), RGB(0, 0, 0))
Next a
wor = PrintWord(4, 9, "指数曲线 y=e^x")
Case 3
For a = 0.0001 To 9 Step Pi / 6000
Dot = DrawDot(a, Loge(a), RGB(0, 0, 0))
Next a
wor = PrintWord(8, 3, "对数曲线 y=ln x")
Case 4
For a = -10 To 10 Step Pi / 6000
Dot = DrawDot(a, Sin(a), RGB(0, 0, 0))
Next a
wor = PrintWord(-5, 2, "正弦曲线 y=sin x")
Case 5
For a = -10 To 10 Step Pi / 6000
Dot = DrawDot(a, Cos(a), RGB(0, 0, 0))
Next a
wor = PrintWord(-9, 2, "余弦曲线 y=cos x")
Case 6
XY
End Select
End Sub
Private Sub Form_Load()
Me.Caption = "数学函数作图?quot;"
Me.Show
Me.AutoRedraw = True
Picture1.AutoRedraw = True
Command1(0).Caption = "二次曲线"
Command1(1).Caption = "一次曲线"
Command1(2).Caption = "指数曲线"
Command1(3).Caption = "对数曲线"
Command1(4).Caption = "正弦曲线"
Command1(5).Caption = "余弦曲线"
Command1(6).Caption = "清空"
XY
End Sub

Private Sub Form_Resize()
Picture1.Width = Me.Width * 0.94
Picture1.Height = Me.Height - (Command1(0).Height * 4 + 100)

Command1(0).Top = Me.Height - (Command1(0).Height * 2.5 + 100)
Command1(0).Left = Me.Width * 0.01

For i = 1 To 6
Command1(i).Top = Me.Height - (Command1(0).Height * 2.5 + 100)
Command1(i).Left = Command1(i - 1).Left + 1000
Next
XY
End Sub