线性方程.frm

饮羽公路测设（glcs） 由20多个公路测量、设计、试验和施工组织设计等小软件组成。如《中桩大地坐标》可以计算不等长缓和曲线的中桩和边桩的大地坐标；《缓和曲线反算》可以根据切线长、外距长或缓和曲线长求

    If SSTab1.Tab = 0 Then  '已知两点
        xa = Val(Text1.Text)
        ya = Val(Text2.Text)
        xb = Val(Text3.Text)
        yb = Val(Text4.Text)
        
        List1.Clear
        List1.AddItem "    －－－－原始数据－－－－"
        List1.AddItem "    " + Label1.Caption + Text1.Text
        List1.AddItem "    " + Label2.Caption + Text2.Text
        List1.AddItem "    " + Label3.Caption + Text3.Text
        List1.AddItem "    " + Label4.Caption + Text4.Text
        
        List1.AddItem ""
        List1.AddItem "    ～～～～线性方程～～～～"
        If xb - xa <> 0 And yb - ya <> 0 Then
            aa = (yb - ya) / (xb - xa)
            bb = yb - aa * xb
            
            List1.AddItem "    " + "Y=" + Trim(Str(aa)) + "X" + "+" + Trim(Str(bb))
        End If
        
        If xb - xa = 0 And yb - ya <> 0 Then
            aa = xa
            bb = 0
            List1.AddItem "    " + "X=" + Trim(Str(aa))
        End If
        
        If xb - xa <> 0 And yb - ya = 0 Then
            aa = 0
            bb = ya
            List1.AddItem "    " + "Y=" + Trim(Str(bb))
        End If
        
        If xb - xa = 0 And yb - ya = 0 Then
            aa = 0
            bb = 0
            List1.AddItem "    " + "为个一点"
        End If
    End If
    
    If SSTab1.Tab = 1 Then '已知一点和K
        xa = Val(Text5.Text)
        ya = Val(Text6.Text)
        k = Val(Text7.Text)
        
        aa = k
        bb = ya - aa * xa
        
        List1.Clear
        List1.AddItem "    －－－－原始数据－－－－"
        List1.AddItem "    " + Label5.Caption + Text5.Text
        List1.AddItem "    " + Label6.Caption + Text6.Text
        List1.AddItem "    " + Label7.Caption + Text7.Text
        
        List1.AddItem ""
        List1.AddItem "    ～～～～线性方程～～～～"
        
        List1.AddItem "    " + "Y=" + Trim(Str(aa)) + "X" + "+" + Trim(Str(bb))
    End If
    
    
    Exit Sub
handlerror:
    xiansh = MsgBox("在计算时出错，请检查数据后再试试。", vbInformation, "信息提示")

End Sub

Private Sub Command2_Click()
'关闭
    
    On Error GoTo handlerror

    If List1.ListCount > 1 And rjsfzc = 88 Then
        frmMain.Text1 = frmMain.Text1 & vbCrLf & ""
        frmMain.Text1 = frmMain.Text1 & vbCrLf & "    《线性方程计算结果》"
        frmMain.Text1 = frmMain.Text1 & vbCrLf & ""
        For i = 0 To List1.ListCount - 1
            frmMain.Text1 = frmMain.Text1 & vbCrLf & List1.List(i)
        Next i
        frmMain.Text1 = frmMain.Text1 & vbCrLf & "    --------------------------------------"
    End If
    
    Unload Me

    Exit Sub
handlerror:

End Sub

Private Sub Command3_Click()
'插值>>>

    On Error GoTo handlerror
    
    xx = Val(Text8.Text)
    yy = aa * xx + bb
    Text9.Text = Trim(Str(yy))
    
    List1.AddItem ""
    List1.AddItem "    X＝" + Trim(Text8.Text) + "    Y＝" + Trim(Text9.Text)
    
    Exit Sub
handlerror:

End Sub

Private Sub Command4_Click()
'插值<<<

    On Error GoTo handlerror
    
    yy = Val(Text9.Text)
    xx = (yy - bb) / aa
    
    Text8.Text = Trim(Str(xx))
    
    List1.AddItem ""
    List1.AddItem "    X＝" + Trim(Text8.Text) + "    Y＝" + Trim(Text9.Text)
    
    Exit Sub
handlerror:

End Sub

Private Sub Form_KeyPress(KeyAscii As Integer)
'Esc键退出，VbEscape可以用27代替
    On Error GoTo handlerror

    If KeyAscii = 27 Then
        Unload Me
    End If
    
    Exit Sub
handlerror:

End Sub

Private Sub Form_Load()
'启动

    On Error GoTo handlerror
    
    Text1.Text = ""
    Text2.Text = ""
    Text3.Text = ""
    Text4.Text = ""
    Text5.Text = ""
    Text6.Text = ""
    Text7.Text = ""
    Text8.Text = ""
    Text9.Text = ""
    
    List1.Clear
    
    Exit Sub
handlerror:

End Sub

Private Sub SSTab1_Click(PreviousTab As Integer)
'点击页面

    On Error GoTo handlerror
    
    If SSTab1.Tab = 0 Then Text1.SetFocus
    If SSTab1.Tab = 1 Then Text5.SetFocus
    If SSTab1.Tab = 2 Then Text8.SetFocus
    
    Exit Sub
handlerror:

End Sub

Private Sub Text1_Click()
'点击
    
    On Error GoTo handlerror
    
    Text1.SelStart = 0
    Text1.SelLength = Len(Text1.Text)
    
    Exit Sub
handlerror:

End Sub

Private Sub Text2_Click()
'点击
    
    On Error GoTo handlerror
    
    Text2.SelStart = 0
    Text2.SelLength = Len(Text2.Text)
    
    Exit Sub
handlerror:

End Sub

Private Sub Text3_Click()
'点击
    
    On Error GoTo handlerror
    
    Text3.SelStart = 0
    Text3.SelLength = Len(Text3.Text)
    
    Exit Sub
handlerror:

End Sub

Private Sub Text4_Click()
'点击
    
    On Error GoTo handlerror
    
    Text4.SelStart = 0
    Text4.SelLength = Len(Text4.Text)
    
    Exit Sub
handlerror:

End Sub

Private Sub Text5_Click()
'点击
    
    On Error GoTo handlerror
    
    Text5.SelStart = 0
    Text5.SelLength = Len(Text5.Text)
    
    Exit Sub
handlerror:

End Sub

Private Sub Text6_Click()
'点击
    
    On Error GoTo handlerror
    
    Text6.SelStart = 0
    Text6.SelLength = Len(Text6.Text)
    
    Exit Sub
handlerror:

End Sub

Private Sub Text7_Click()
'点击
    
    On Error GoTo handlerror
    
    Text7.SelStart = 0
    Text7.SelLength = Len(Text7.Text)
    
    Exit Sub
handlerror:

End Sub

Private Sub Text8_Click()
'点击
    
    On Error GoTo handlerror
    
    Text8.SelStart = 0
    Text8.SelLength = Len(Text8.Text)
    
    Exit Sub
handlerror:

End Sub

Private Sub Text9_Click()
'点击
    
    On Error GoTo handlerror
    
    Text9.SelStart = 0
    Text9.SelLength = Len(Text9.Text)
    
    Exit Sub
handlerror:

End Sub