VB常见程序段(补充中).doc

Visual Basic基本程序段为节省版面，省略部分程序段的事件和声明语句。一面向过程的程序段1. 窗体充满屏幕的3种方法Form1.Left = 0Form1.Top = 0Form1.Width = Screen.WidthForm1.Height = Screen.HeightForm1.Move 0, 0, Screen.Width, Screen.HeightForm1.WindowState = 22. 在窗体显示符号金字塔的4种程序结构按符号数设置行循环按空格数设置行循环按行号I计算符号数为奇数I * 2 1空格数递减(7 I)空格数递减：I = 6 - 0符号数为奇数13 - I * 2用循环显示各行的符号For I = 1 To 7 Print Spc(7 - I); For J = 1 To I * 2 - 1 Print $; Next J PrintNext IFor I = 6 To 0 Step -1 Print Spc(I); For J = 1 To 13 - I * 2 Print $; Next J PrintNext I用String()函数显示各行的符号For I = 1 To 7 Print Spc(7 - I); String(I * 2 - 1, $)Next IFor I = 6 To 0 Step -1 Print Spc(I); String(13 - I * 2, $)Next I3. 符号图形Dim I As Integer, nCs As IntegernCs = 7 层数Print Tab(nCs); * 第一层For I = 2 To nCs Print Tab(nCs + 1 - I); *; Tab(nCs); *; Tab(nCs - 1 + I); *Next I* * * *4. 三个数中寻找最大数的2种方法If a b And a c Then Print 最大数是第1个:; aIf b a And b c Then Print 最大数是第2个:; bIf c b And c a Then Print 最大数是第3个:; cMax = aIf b Max Then Max = bIf c Max Then Max = cPrint 最大数是; Max5. 数组中找最大数的2种方法Max = 0For I = 1 To 100 If X(I) Max Then Max = X(I)Next IPrint 这100个数的最大数; MaxMax = X(1)For I = 2 To 30 If X(I) Max Then Max = X(I)Next IPrint 这30个数的最大数; Max6. 求阶乘和累加Temp = 1For I = 1 To n Temp = Temp * INext ITemp = 0For I = 1 To n Temp = Temp + INext I7. 计算级数1- (1/2) + (1/4) - (1/8) + . + (1/2n) 的4种方法S = 1For I = 1 To n Step 2 S = S - 1 / 2 I + 1 / 2 (I + 1)Next IS = 1For I = 1 To n S = S + (- 1 / 2) INext IS = 1f = -1For I = 1 To n S = S + f / 2 I f = -fNext IS = 1For I = 1 To n If I Mod 2 0 Then S = S - 1 / 2 I Else S = S + 1 / 2 I End IfNext I8. 寻找级数项的递变规律1+2+3+.+100S = S + I1/(1*2)+1/(2*3)+1/(3*4)+1/(20*21)S = S + 1 / I / ( I + 1 )(1/(7*9)+(1/(9*11)+.+(1/(n*(n+2)S = S + 1 / I / ( I + 2 )1+x/2+x2/3+x3/4+x19/20S = S + x I / ( I + 1 )1+3+32+33+.+340F = F * 3S = S + F1!+2!+.+20!F = F * I S = S + F1/1!+1/2!+1/3!+1/n!F = F / I S = S + F1+x/1!+x2/2!+x3/3!+xn/n!F = F * x / I S = S + F2+22+222+2222+F = F + 2 * 10 I S = S + F5+55+555+5555+55555+F = F * 10 + 5 S = S + F9. 判断X是否为素数的2种方法For I = 2 To Sqr(X) If X Mod I = 0 Then IsPrime = False : Exit For Else IsPrime = True End IfNext IFor I = 2 To Sqr(X) If X Mod I = 0 Then Exit ForNext IIf I Sqr(X) Then IsPrime = True10. 交换形式参数A和B的子程序Sub Swap(A, B) : Temp = A : A = B : B = Temp : End Sub11. 产生10个各不相同的随机数的3种方法For I = 1 To 10 B = True Do While B A(I) = Int(10 + Rnd * 20) B = False For J = 1 To I - 1 If A(I) = A(J) Then B = True Exit For End If Next J Loop Print A(I);Next IFor I = 1 To 10 Do A(I) = Int(10 + Rnd * 20) For J = 1 To I - 1 If A(I) = A(J) Then Exit For Next J Loop Until J = I Print A(I);Next IFor i = 1 To 10 A(i) = Int(10 + Rnd * 20) For j = 1 To i - 1 If A(i) = A(j) Then Exit For Next j If j = i Then Print A(i); Else i = i - 1Next i12. 冒泡法排序: 从第一个数开始往后扫描，找到一个比它小的数，就将它交换到第一个位置，然后再用它继续比较后面的数，直至找出最小的数放在第一个位置；然后再从第二个数开始扫描Dim A(10) As Integer, I As Integer, J As IntegerFor I = 1 To 9 For J = I + 1 To 10 If A(I) A(J) Then Swap A(I), A(J)找到比它小的数，就将它交换到第一个位置Next J, I13. 选择法排序：从第一个数开始往后扫描，找出所有数中最小数的位置，将这个数放到第一个位置；然后再从第二个数开始扫描.Dim A(10) As Integer, I As Integer, J As Integer, P As IntegerFor I = 1 To 9 P = I 用变量P保存最小数的下标，先假定A(I)最小 For J = I + 1 To 10 If A(J) A(P) Then P = J变量P始终保存最小数的下标，先不交换 Next J If I P Then Swap A(I), A(P) 完成J循环，A(I)不是最小，则交换Next I14. 插入法排序：排序时，每次都将最新的数插入到合适的位置，直到所有的数都放在合适的位置上Dim A(10) As Integer, I As Integer, J As Integer, Temp As IntegerFor I = 2 To 10 Temp = A(I) J = I - 1 Do While J 0 And Temp A(J) 最新的数要在前面已排好序的数中找位置 A(J + 1) = A(J) 将前面已排好序的数往后移动,腾出位置来给最新的数 J = J - 1 Loop If J I - 1 Then A(J + 1) = Temp 将最新的数插入到找到的位置j+1中Next I15. 将数组A()以每行5个显示For I = 1 To 100 Print A(I); If I Mod 5 = 0 Then PrintNext IFor I = 0 To 99 Print Tab(1 + (I Mod 5) * 6); A(I);Next I16. 矩阵赋值两条对角线元素置为1，其余为0。如下所示。For I = 1 To 5 For J = 1 To 5 If J = I Or J = 6 - I Then M(I, J) = 1 Else M(I, J) = 0 Next JNext I对角线元素置为0，上三角为1，下三角为-1。如右所示。For I = 1 To 5 For J = 1 To 5 Select Case J Case I:M(I, J) = 0 Case Is I:M(I, J) = 1 Case Else:M(I, J) = -1 End SelectNext J, I17. 矩阵赋值为两位随机正整数和矩阵显示For I = 1 To 5 For J = 1 To 5 M(I, J) = Int(Rnd() * 90) + 10 Next JNext I For I = 1 To 5 For J = 1 To 5 Print M(I, J), Next J PrintNext I18. 求矩阵对角线元素之和求矩阵一条对角线元素之和Sum = 0For I = 1 To 5 Sum = Sum + M(I, I)Next I求矩阵两条对角线元素之和Sum = 0For I = 1 To 5 Sum = Sum + M(I, I) + M(I, 6 - I)Next I19. 矩阵转置的2种方法For I = 1 To 4 For J = I + 1 To 5 Swap M(I, J), M(J, I)Next J, IFor I = 2 To 5 For J = 1 To I - 1 Swap M(I, J), M(J, I)Next J, I20. 输入框的过滤（要求X Y）DoX = Val(InputBox(请输入（X Y）)Y = Val(InputBox(请输入（X Y）)Loop Until X YDoX = Val(InputBox(请输入（X Y）)Y = Val(InputBox(请输入（X Y）)Loop While X Width Then Label1.Left = -Label1.Width Else Label1.Move Label1.Left + 100End Sub24. 标签显示为黄色和红色交替Private Sub Timer1_Timer() If Label1.ForeColor = vbYellow Then Label1.ForeColor = vbRed Else Label1.ForeColor = vbYellowEnd Sub25. 单击命令按钮变换按钮标题Private Sub Command1_Click() If Command1.Caption = 运行 Then Command1.Caption = 暂停 Else Command1.Caption = 运行End Sub26. 文本框最多只能接受6个字符，并且输入的字符显示为“*”。Private Sub Form_Load() Text1.MaxLength = 6 Text1.PasswordChar = *End Sub 27. 在文本框中只允许输入数字Private Sub Text1_KeyPress(KeyAscii As Integer) If KeyAscii Asc(“9”) Or KeyAscii Asc(“0”) Then KeyAscii = 0End Sub28. 密码检验，密码错误提示，允许输入3次。Private Sub Command1_Click() Static N As Byte If Text1 = 123456 Then MsgBox 登录成功！: Exit Sub N = N + 1 Select Case N Case 1 MsgBox 请重试！, vbInformation, 登录 Case 2 MsgBox 最后一次重试！, vbQuestion, 登录 Case Else MsgBox 你无权使用本系统！, vbCritical, 登录 End End SelectEnd Sub29. 文本框内容全部选中Text1.SelStart=0 ：Text1.SelLength = Len(Text1)30. 剪切Clipboard.SetText Text1.SelText复制选中的文本到剪贴板上 Text1.SelText = 删除选中的文本31. 复制Clipboard.SetText Text1.SelText复制选中的文本到剪贴板上32. 粘贴Text1.SelText = Clipboard.GetText用剪贴板上的文本替换选中的文本33. 清除剪贴板Clipboard.Clear清除剪贴板上的内容34. 标签随文本框同步显示Private Sub Text1_Change() Label1.Caption = Text1.TextEnd Sub35. 删除多选列表框内的所选内容For I = List1.ListCount - 1 To 1 Step -1 If List1.Selected(I) = True Then List1.RemoveItem INext I36. 用单选按钮控件数组和复选框控件数组改变字体和字型Private Sub Check1_Click(Index As Integer) Text1.FontBold = Check1(0) Text1.FontItalic = Check1(1)End SubPrivate Sub Option1_Click(Index As Integer) Text1.FontName = Option1(Index).CaptionEnd SubPrivate Sub Form_Load() Option1(0).Caption = 宋体 Option1(1).Caption = 黑体 Option1(2).Caption = 楷体_GB2312 Check1(0).Caption = 加粗Check1(1).Caption = 倾斜End Sub37. 滚动条(标签内容随滚动条改变而改变)Private Sub Form_load()HScroll1.Max = 250 : HScroll1.Min = 10 HScroll1.LargeChange = 50 HScroll1.SmallChange = 10 HScroll1.Value = 10End SubPrivate Sub Hscroll1_change() Label1.Caption = HScroll1.Value Label1.FontSize = HScroll1.Value Label1.ForeColor = HScroll1.ValueEnd Sub 38. 绘图(产生随机点)Private Sub Command1_click() For I = 1 To 10000 R = 255 * Rnd : G = 255 * Rnd : B = 255 * Rnd 设置三色为随机数 X = Rnd * ScaleWidth: Y = Rnd * ScaleHeight 随机定位 PSet (X, Y), RGB(R, G, B)用随机色画点 NextEnd Sub 39. 画板（画图）Dim nColor&Private Sub Picture1_MouseUp(Button%, Shift%, X!, Y!) 鼠标右键用于取色 If Button = 2 Then nColor = Picture1.Point(X, Y)End SubPrivate Sub Picture1_MouseDown(Button%, Shift%, X!, Y!) 鼠标左键确定起始 If Button = 1 Then Picture1.CurrentX = X : Picture1.CurrentY = YEnd SubPrivate Sub Picture1_