一个计算机控制的试验程序

Dim Xe, Ye, Nxy, Xm, Ym, Fm, Xm0, Ym0, JianGe As Integer   '定义全局变量
'==================================================
Private Sub Command1_Click()                               '画直线按钮程序
Xe = CInt(Text1.Text)                                      '取Xe的值
Ye = CInt(Text2.Text)                                      '取Ye的值
DrawWidth = 5
Line (0, 0)-(Xe, Ye), vbRed                                '设置画线的宽度和颜色
JianGe = CInt(Text3.Text)                                  '取间隔值
PSet (0, 0), vbRed                                         '显示圆点坐标和颜色
Nxy = (Xe + Ye) / JianGe
Xm = 0
Ym = 0
Xm0 = 0
Ym0 = 0
Fm = 0
Xe = Xe / JianGe
Ye = Ye / JianGe

DrawWidth = 1
';;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
Draw_line:
           Xm0 = Xm
           Ym0 = Ym
           If Fm >= 0 Then
             Xm = Xm + JianGe
             Fm = Fm - Ye
           Else
             Ym = Ym + JianGe
             Fm = Fm + Xe
           End If
           Nxy = Nxy - 1
           Line (Xm0, Ym0)-(Xm, Ym)
           DrawWidth = 2
           PSet (Xm, Ym)
           DrawWidth = 1
           If Nxy = 0 Then
           DrawWidth = 5
           PSet (Xm, Ym)
           Else
           GoTo Draw_line
           End If
End Sub
'================================================
Private Sub Command2_Click()                           '画圆按钮的程序
Xm = CInt(Text4.Text)                                  '取半径的值
Ym = 0
DrawWidth = 5                                          '设置线宽和点的直径
Circle (0, 0), Xm, vbRed                               '画圆函数和颜色的设置
JianGe = CInt(Text3.Text)                              '取间隔值
PSet (0, 0), vbRed                                     '画点函数和颜色的设置
Xm0 = 0
Ym0 = 0
Nxy = Xm * 2 / JianGe                                  '计算步数
Fm = 0

DrawWidth = 1                                          '设置线宽
';;;;;;;;;;;;;;;;;;;;;;;;;;;;
Draw_yuan:
          Xm0 = Xm
          Ym0 = Ym
          If Fm >= 0 Then
          Xm = Xm - JianGe
          Fm = Fm - 2 * Xm0 + JianGe
          Else
          Ym = Ym + JianGe
          Fm = Fm + 2 * Ym0 + JianGe
          End If
          Nxy = Nxy - 1
          Line (Xm0, Ym0)-(Xm, Ym)
          DrawWidth = 2
          PSet (Xm, Ym)
          DrawWidth = 1
          If Nxy = 0 Then
          DrawWidth = 5
          Xe = CInt(Text4.Text)
          PSet (0, Xe)
          Else
          GoTo Draw_yuan
          End If
End Sub
'============================================
Private Sub Command3_Click()                         '清除框体显示程序
Form1.Cls
End Sub