Visual Basic程序设计教程(第2版)课后部分编程题参考答案.doc

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 SubPrivate Sub Form_DblClick() Label1.Caption = 你双击了窗体End Sub3 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 * xEnd Sub第2章13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 SubPrivate Sub Command2_Click() 还原按钮 Form1.WindowState = 0 还原End SubPrivate Sub Command3_Click() 最小化按钮 Form1.WindowState = 1 最小化End Sub5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 * yEnd Sub6. 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 = xEnd 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 Sub2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 = tEnd SubPrivate Sub Command2_Click() “合并” t = Text1.Text + Text2.Text + Text3.Text Text4.Text = tEnd Sub3. (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 = 0End SubPrivate Sub Command2_Click() 往右 Text1.Left = Form1.Width - Text1.WidthEnd SubPrivate Sub Command3_Click() 居中 Text1.Left = (Form1.Width - Text1.Width) / 2End Sub5. Private Sub Cmd1_Click() Lab1.Visible = True Lab1.Caption = 您已下达显示命令End SubPrivate Sub Form_Click() Cmd1.Visible = TrueEnd Sub6. Private Sub Form_KeyPress(KeyAscii As Integer) Show Print 输入字符：; Chr(KeyAscii), ASCII码为; KeyAsciiEnd SubPrivate Sub Form_DblClick() ClsEnd 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 IfEnd Sub2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(06) 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 SelectEnd Sub3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.SetFocusEnd SubPrivate Sub Form_Load() Text1.Text = Text1.MaxLength = 8 Text1.PasswordChar = *End Sub4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.SetFocusEnd SubPrivate 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 + sEnd Sub5 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 Sub6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 = 1000End Sub Private Sub TimClk_Timer() LabClk.Caption = Val(LabClk.Caption) + 1End Sub7 (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 sEnd Sub2. 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 iEnd Sub3. 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; xn1End 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 & k & 个数) Print a(k); 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 kEnd Sub2. 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 iEnd Sub3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 Sub4(1) g(x - 10) + 1 (2) n - 1 (3) g(t) g(j) (4) m = s(t): s(t) = s(k): s(k) = m 5在窗体上建立4行3列共12个元素的文本框控件数组Text1(0)Text1(11)Private Sub Form_Load() Dim t(12) As String Randomize For k = 1 To 12 t(k) = Empty 初始安排12个位置均为Empty Next k For h = 65 To 74 代表A至J，每次随机安排一个字母 Do While True 随机查找一个空位 p = Int(1 + 12 * Rnd) 产生112随机数 If t(p) = Empty Then t(p) = Chr(h) Exit Do End If Loop Next h For k = 1 To 12 Text1(k - 1).Text = t(k) 显示座位分配情况 Next kEnd Sub第7章1. 在窗体上建立四个文本框Text1和一个命令按钮Command1(“检验”)。文本框Text1Text3用于输入，Text4用于输出结果。Private Sub Command1_Click() Dim a As String, b As String, c As String a = Trim(Text1.Text) b = Trim(Text2.Text) c = Trim(Text3.Text) If che(a) And che(b) And che(c) Then Text4.Text = Val(a) + Val(b) + Val(c) Else Text4.Text = 存在非数字字符 End IfEnd SubFunction che(x As String) As Boolean 若存在非数字字符，函数值为假 che = True For k = 1 To Len(x) s = Mid(x, k, 1) If s 9 Then che = False Exit For End If Next kEnd Function2在窗体上建立七个文本框Text1Text7和一个命令按钮Command1(“比较”)。Text1Text6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 = mEnd SubSub max(x, y, z, m) 标准模块文件 If x y Then m = x Else m = y End If If m z Then m = z End IfEnd Sub3. (1) s (2) Mid(s, p+1) (3) n4. 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 SubFunction Power(x As Single, n As Integer) As Double If n 1 Then Power = Power(x, n - 1) * x Else Power = x End IfEnd Function5 在窗体上设置三个窗体Form1Form3。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 IntegerPrivate 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 SubPrivate Sub Form_Activate() Text1.Text = :Text2.Text = Text1.SetFocusEnd SubPrivate Sub Command1_Click() 窗体Form2的“返回” Form2.Hide Form1.ShowEnd SubPrivate Sub Command1_Click() 窗体Form3的“退出” Unload Form1 Unload Form2Unload Form3 EndEnd Sub 6. (1) Form1窗体模块程序代码：Private Sub Form_Load() RandomizeEnd SubPrivate 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 SubPrivate Sub Command2_Click() 求最大数 Text2.Text = Max()End SubPrivate 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 SubPrivate Sub Command4_Click() 结束 Unload Form1 隐藏主窗体 Unload Form2 显示“排序”窗体 EndEnd 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 = tEnd SubPrivate 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 SingleFunction 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 IntegerPrivate Sub Command1_Click() 产生随机数 For i = 1 To 20 d(i) = Int(1 + 99 * Rnd) List1.AddItem d(i) Next iEnd SubPrivate Sub Command2_Click() 保存 Open MyFile3.txt For Output As #1 For i = 1 To 20 Write #1, d(i) Next i Close #1End SubPrivate 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 #1End SubPrivate Sub Command4_Click() 结束 EndEnd Sub2 本程序的用户界面和程序代码较为复杂，请见具体程序文件。第9章1. 程序代码如下：Private Sub Form_load() Dim x(3) As Single, y As Single On Error GoTo errln 以后出错时转移到errln y = 2 / 0 产生除数为0的错误 x(4) = 1 产生下标越界的错误 MsgBox (终止程序的运行) Unload Me 卸载窗体 Enderrln: 标号Select Case Err.Number Case 11 除数为0的错误码为11 MsgBox (除数为0(错误码为11)，跳过该错误) Resume Next 返回 Case 9 下标越界的错误码为9 MsgBox (下标越界(错误码为9)，跳过该错误) Resume Next 返回 Case Else 其他错误处理 MsgBox (错误发生在 & Err.Source _ & , 代码为 & Err.Number _ & , 即 & Err.Description) End SelectEnd Sub2改正后的程序代码如下：Private Sub Form_Load() Show For i = 1 To 11 Print Tab(20 - i); For j = 1 To 2 * i - 1 If j 9 Then k = k + 7 Print Chr(k + 48); Next j Next iEnd Sub3(1) n = n + 1 (2) d(1, j) = d(3, j) (3) d(i, 2) = d(i, 4) (4) i = j (5) d(i, j) = d(i, j) + 1 (6) n = 0 (7) Text1.Text第10章1在窗体上建立一个水平滚动条HScroll1和一个文本框Text1。程序代码如下：Private Sub Form_Load() HScroll1.Max = 1000 HScroll1.Min = 0 HScroll1.LargeChange = 5 HScroll1.LargeChange = 10 HScroll1.Value = 500End SubPrivate Sub HScroll1_Change() Text1.Text = HScroll1.ValueEnd SubPrivate Sub HScroll1_Scroll() Text1.Text = HScroll1.ValueEnd Sub 2. 在窗