《Visual Basic程序设计教程(第2版)》课后部分编程题参考答案

第1章 1. 按要求设置窗体属性 2．在窗体上建立一个标签Label1。程序代码如下： Private Sub Form_Click() Label1.Caption = “你单击了窗体“ End Sub Private Sub Form_DblClick() Label1.Caption = “你双击了窗体“ End Sub 3． 在窗体上建立两个文本框Text1(输入数)、Text2(输出数)和一个命令按钮Command1。两个文本框的Text属性均为空。 Private Sub Command1_Click() Dim x As Single x = Val(Text1.Text) Text2.Text = 15 * x End Sub 第2章 1～3题：按要求完成操作练习。 4． Private Sub Command1_Click() “最大化“按钮 Form1.WindowState = 2 最大化 End Sub Private Sub Command2_Click() “还原“按钮 Form1.WindowState = 0 还原 End Sub Private Sub Command3_Click() “最小化“按钮 Form1.WindowState = 1 最小化 End Sub 5．在窗体上建立三个文本框Text1(第一个数)、Text2(第二个数)、Text3(计算结果)和一个命令按钮Command1(“计算”)。 Private Sub Command1_Click() Dim x As Single Dim y As Single x = Val(Text1.Text) y = Val(Text2.Text) Text3.Text = x * x + y * y End Sub 6. 在窗体上建立两个文本框Text1(输入一串字符)、Text2(输出结果)和一个命令按钮Command1。 Private Sub Command1_Click() Dim x As String x = Left(Text1.Text, 1) + Right(Text1.Text, 1) Text2.Text = x End Sub 第3章 1．在窗体上建立一个文本框Text1(输入n值)、三个标签Label1(第一个随机数)、Label2(第二个随机数)和Label3(第三个随机数)，以及一个命令按钮Command1。 Private Sub Command1_Click() n = Val(Text1.Text) Randomize x = Int(1 + n * Rnd) Label1.Caption = “第一个随机数“ + Str(x) x = Int(1 + n * Rnd) Label2.Caption = “第二个随机数“ + Str(x) x = Int(1 + n * Rnd) Label3.Caption = “第三个随机数“ + Str(x) End Sub 2．在窗体上建立了四个文本框Text1、Text2、Text3和Text4，以及一个命令按钮Command1(“交换”)和Command2(“合并”)。 Private Sub Command1_Click() “交换” t = Text1.Text Text1.Text = Text2.Text Text2.Text = Text3.Text Text3.Text = t End Sub Private Sub Command2_Click() “合并” t = Text1.Text + Text2.Text + Text3.Text Text4.Text = t End Sub 3. (1) Rnd * 9000 + 1000 (2) Str(x) (3) Mid(s, 3, 1) + Mid(s, 2, 1) + Left(s, 1) 4. Private Sub Command1_Click() 往左 Text1.Left = 0 End Sub Private Sub Command2_Click() 往右 Text1.Left = Form1.Width - Text1.Width End Sub Private Sub Command3_Click() 居中 Text1.Left = (Form1.Width - Text1.Width) / 2 End Sub 5. Private Sub Cmd1_Click() Lab1.Visible = True Lab1.Caption = “您已下达显示命令“ End Sub Private Sub Form_Click() Cmd1.Visible = True End Sub 6. Private Sub Form_KeyPress(KeyAscii As Integer) Show Print “输入字符：“; Chr(KeyAscii), “ASCII码为;“; KeyAscii End Sub Private Sub Form_DblClick() Cls End Sub 7. 产生这三个消息框的相应语句是： 产生第1个消息框：x = MsgBox(“在这里显示提示信息“, 4 + 0, “请确认“) 产生第2个消息框：x = MsgBox(“在这里显示“ + Chr(13) + “提示信息“,3 + 0,“请确认“) 产生第3个消息框：x = MsgBox(“在这里显示“+Chr(13)+“提示信息“,2 + 16 + 0,“请确认“) 第4章 1. 在窗体上建立两个文本框Text1(输入数)及Text2(显示结果)，一个命令按钮Command1(“判断”)。 Private Sub Command1_Click() “判断” x = Val(Text1.Text) If x Mod 2 = 0 Then Text2.Text = “偶数“ Else消息 Text2.Text = “奇数“ End If End Sub 2．窗体上建立了一个文本框Text1，用于显示结果。 Private Sub Form_Load() x = Val(InputBox(“请输入星期几(0～6)“)) Select Case x Case Is = 0 Text1.Text = “星期日(Sunday)“ Case Is = 1 Text1.Text = “星期一(Monday)“ Case Is = 2 Text1.Text = “星期二(Tuesday)“ Case Is = 3 Text1.Text = “星期三(Wednesday)“ Case Is = 4 Text1.Text = “星期四(Thursday)“ Case Is = 5 Text1.Text = “星期五(Friday)“ Case Is = 6 Text1.Text = “星期六(Saturday)“ Case Else Text1.Text = “输入错误“ End Select End Sub 3．窗体上建立了一个文本框Text1(“输入口令”)和一个命令按钮Command1(“检查”)。 Private Sub Command1_Click() “检查” x = Text1.Text If x = “12345678“ Then MsgBox (“欢迎你用机!“) Else MsgBox (“对不起，口令错“) End If Text1.Text = ““ Text1.SetFocus End Sub Private Sub Form_Load() Text1.Text = ““ Text1.MaxLength = 8 Text1.PasswordChar = “*“ End Sub 4．窗体上建立了两个文本框Text1(输入字符串)及Text2(转换结果)，一个命令按钮Command1(“清除”)。 Private Sub Command1_Click() “清除” Text1.Text = ““ Text2.Text = ““ Text1.SetFocus End Sub Private Sub Text1_KeyPress(KeyAscii As Integer) Dim s As String * 1 s = Chr(KeyAscii) Select Case s Case “A“ To “Z“ s = LCase(s) Case “a“ To “z“ s = UCase(s) Case Else s = “*“ End Select Text2.Text = Text2.Text + s End Sub 5． 分别选择”红”、 ”绿”、 ”蓝”复选框后，单击命令按钮Command1时，通过RGB函数调配的颜色作为一个标签的背景色（BackColor）。 Private Sub Command1_Click() r = 0: g = 0: b = 0 If Check1.Value = 1 Then ”红”复选框 r = 255 End If If Check2.Value = 1 Then ”绿”复选框 g = 255 End If If Check3.Value = 1 Then ”蓝”复选框 b = 255 End If Label1.BackColor = RGB(r, g, b) End Sub 6．程序代码如下： Private Sub Form_Load() LabClk.Caption = “0“ LabClk.Alignment = 1 LabClk.BorderStyle = 1 LabClk.FontSize = 22 LabClk.FontName = “黑体“ TimClk.Interval = 1000 End Sub Private Sub TimClk_Timer() LabClk.Caption = Val(LabClk.Caption) + 1 End Sub 7． (1) Chr(KeyAscii) (2) ElseIf Chr(KeyAscii) (3) CheC = CheC - 1 (4) CheC (5) Is > 0 或 Else 第5章 1. 和数为：1.21。程序代码如下： Private Sub Form_Load() Show s = 0 For k = 1 To 100 s = s + 1 / (1 + k * 4) Next k Print s End Sub 2. 程序代码如下： Private Sub Form_Load() Dim i As Integer, a As Integer, b As Integer, c As Integer Show For i = 100 To 999 a = Int(i / 100) b = Int((i - 100 * a) / 10) c = i - 100 * a - 10 * b If a * a * a + b * b * b + c * c * c = i Then Print i End If Next i End Sub 3. 在窗体上建立一个文本框Text1(初始值)、一个列表框List1(显示结果)和一个命令按钮Comd1(“查找”)。 Private Sub Comd1_Click() “查找” Dim n As Integer n = Val(Text1.Text) List1.Clear:k = 0 Do While k = “A“ And t = 0.00001 Print a; “的平方根为“; xn1 End Sub 第6章 1. 程序代码如下： Private Sub Form_Load() Show Dim a(100) As Single n = Val(InputBox(“输入个数n“)) Print “处理前数据 :“ For k = 1 To n a(k) = Val(InputBox(“请输入第“ Next k Print M = Int(n / 2) For k = 1 To M h = n - k + 1 t = a(h):a(h) = a(k):a(k) = t Next k Print “处理的结果 :“ For k = 1 To n Print a(k); Next k End Sub 2. 程序代码如下： Private Sub Form_Load() Dim a(6, 6) As Integer Show For i = 1 To 6 For j = 1 To 6 Select Case i Case Is j a(i, j) = 2 Case Is = j a(i, j) = 0 End Select Print a(i, j); Next j Print Next i For i = 1 To 6 t = a(1, i):a(1, i) = a(6, i):a(6, i) = t Next i Print: Print For i = 1 To 6 For j = 1 To 6 Print a(i, j); Next j Print Next i End Sub 3．在窗体上建立两个列表框List1(处理前数据)和List2(处理后数据)，以及标签Label1。程序代码如下： Private Sub Form_Load() Dim a(100) As Integer, b(100) As Integer Randomize n = 100 For i = 1 To n 输入数组a的n个元素 x = Int(20 * Rnd) List1.AddItem x a(i) = x Next i k = 0 For i = 1 To n 删除零元素 If a(i) 0 Then k = k + 1 : b(k) = a(i) : List2.AddItem b(k) End If Next i Label1.Caption = “数组中零元素个数：“ + Str(n - k) End Sub 4．(1) g(x - 10) + 1 (2) n - 1 (3) g(t) “9“ Then che = False Exit For End If Next k End Function 2．在窗体上建立七个文本框Text1～Text7和一个命令按钮Command1(“比较”)。Text1～Text6用于输入，Text7用于输出结果。 Private Sub Command1_Click() a = Val(Text1.Text):b = Val(Text2.Text):c = Val(Text3.Text) d = Val(Text4.Text):e = Val(Text5.Text):f = Val(Text6.Text) Call max(a, b, c, m) Call max(m, d, e, m) Call max(m, f, f, m) Text7.Text = m End Sub Sub max(x, y, z, m) ‘标准模块文件 If x > y Then m = x Else m = y End If If m ““ (2) Mid(s, p+1) (3) n 4. 程序代码如下： Private Sub Form_Load() Dim x As Single, n As Integer, y As Double x = InputBox(“x=“, “求X的n次方“) n = InputBox(“n=“, “求X的n次方“) y = Power(x, n) Show Print x; “的“; n; “次方=“; Format(y, “###,###.##“) End Sub Function Power(x As Single, n As Integer) As Double If n > 1 Then Power = Power(x, n - 1) * x Else Power = x End If End Function 5． 在窗体上设置三个窗体Form1～Form3。Form1中建立了两个文本框Text1(“用户名”)和Text2(“密码”)，以及命令按钮Command1(“判断”)。Form2中建立了一个文本框Text1(其Text属性值为“欢迎你使用本系统”)和命令按钮Command1(“返回”)。Form3中建立了一个文本框Text1(其Text属性值为“对不起，请向管理员查询”)和命令按钮Command1(“退出”)。 Dim n As Integer Private Sub Command1_Click() ‘窗体Form1的“判断” usern = Trim(Text1.Text):passw = Trim(Text2.Text) If usern = “username“ And passw = “password“ Then Form1.Hide Form2.Show Else n = n + 1:Text1.SetFocus If n = 3 Then Form1.Hide Form3.Show End If End If Text1.Text = ““:Text2.Text = ““ End Sub Private Sub Form_Activate() Text1.Text = ““:Text2.Text = ““ Text1.SetFocus End Sub Private Sub Command1_Click() ‘窗体Form2的“返回” Form2.Hide Form1.Show End Sub Private Sub Command1_Click() ‘窗体Form3的“退出” Unload Form1 Unload Form2 Unload Form3 End End Sub 6. (1) Form1窗体模块程序代码： Private Sub Form_Load() Randomize End Sub Private Sub Command1_Click() “生成随机数“ Dim s As String s = ““ For i = 1 To 10 a(i) = Int(11 + 90 * Rnd) s = s + Str(a(i)) + “,“ Next i Text1.Text = Left(s, Len(s) - 1) End Sub Private Sub Command2_Click() “求最大数“ Text2.Text = Max() End Sub Private Sub Command3_Click() “打开排序窗口“ Form1.Hide 隐藏主窗体 Form2.Show 显示“排序”窗体 End Sub Private Sub Command4_Click() “结束“ Unload Form1 隐藏主窗体 Unload Form2 显示“排序”窗体 End End Sub (2) Form2窗体模块程序代码： Private Sub Command1_Click() “排序” Dim t As String Call Sort(t) Text1.Text = t End Sub Private Sub Command2_Click() “返回” Form2.Hide 隐藏“排序”窗体 Form1.Show 显示主窗体 End Sub (3) 标准模块程序代码： Public a(1 To 10) As Single Function Max() As Single 求最大值 Dim m As Single m = a(1) For i = 2 To 10 If m a(j) Then t = a(i): a(i) = a(j): a(j) = t End If Next j s = s + Str(a(i)) + “,“ Next i s = s + Str(a(10)) End Sub 第8章 1. 程序代码如下： Dim d(1 To 20) As Integer Private Sub Command1_Click() “产生随机数“ For i = 1 To 20 d(i) = Int(1 + 99 * Rnd) List1.AddItem d(i) Next i End Sub Private Sub Command2_Click() “保存“ Open “MyFile3.txt“ For Output As #1 For i = 1 To 20 Write #1, d(i) Next i Close #1 End Sub Private Sub Command3_Click() “读出“ Open “MyFile3.txt“ For Input As #1 Do While Not EOF(1) Input #1, x List2.AddItem x Loop Close #1 End Sub Private Sub Command4_Click() “结束“ End End Sub 2． 本程序的用户界面和程