《VB程序设计》课堂例题总结(2)

If UCase(strc) >= \ Text1.Text = strc & \是字母\

ElseIf strc >= \ Text1.Text = strc & \是数字\Else

Text1.Text = strc & \是其它字符\End If End Sub 方法二：

Private Sub Command2_Click() Dim strc As String * 1

strc = InputBox(\请输入一个符号：\Select Case strc

Case \ Text1.Text = strc & \是字母\ Case \

Text1.Text = strc & \是数字\ Case Else

Text1.Text = strc & \是其它字符\End Select End Sub

模拟计算器 方法一：

Private Sub Command1_Click()

Dim sInput1 As Single, sInput2 As Single, oper As String * 1 Dim iError As Integer sInput1 = Val(Text1.Text) sInput2 = Val(Text3.Text) oper = Trim(Text2) If oper = \

Text4.Text = Str(sInput1 + sInput2) ElseIf oper = \

Text4.Text = Str(sInput1 - sInput2) ElseIf oper = \

Text4.Text = Str(sInput1 * sInput2) ElseIf oper = \

If sInput2 <> 0 Then

Text4.Text = Str(sInput1 / sInput2) Else

MsgBox (\分母为零,出错\ Text3.Text = \ Text3.SetFocus End If

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Else

MsgBox (\运算符出错,再输入\ Text2.Text = \ Text2.SetFocus End If End Sub 方法二：

Private Sub Command2_Click()

Dim sInput1 As Single, sInput2 As Single Dim iError As Integer sInput1 = Val(Text1.Text) sInput2 = Val(Text3.Text) Select Case Trim(Text2) Case \

Text4.Text = Str(sInput1 + sInput2) Case \

Text4.Text = Str(sInput1 - sInput2) Case \

Text4.Text = Str(sInput1 * sInput2) Case \

If sInput2 <> 0 Then

Text4.Text = Str(sInput1 / sInput2) Else

MsgBox (\分母为零,出错\ Text3.Text = \ Text3.SetFocus End If Case Else

MsgBox (\运算符出错,再输入\ Text2.Text = \ Text2.SetFocus End Select End Sub

开始运行如左下图所示，单击“出题”按钮后计算机自动出题，窗口如右下图所示，此时由用户输入加法运算答案，然后单击“判定”按钮。如果用户运算正确则提示“运算正确”，否则显示“运算错误”。再次按下“出题”就会再出一道题。 Private Sub Form_Load() Randomize

Command1.Caption = \出题\End Sub

Private Sub Command1_Click()

If Command1.Caption = \出题\

Text1 = Int(Rnd * 101): Text2 = Int(Rnd * 101) Text3.SetFocus

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Command1.Caption = \判定\ Else

If Val(Text1) + Val(Text2) = Val(Text3) Then MsgBox (\答对了，你真聪明！\ Command1.Caption = \出题\ Text1 = \ Else

MsgBox (\错了，努力啊！\ Text3 = \

Text3.SetFocus End If End If End Sub

Private Sub Command2_Click() End End Sub

修改密码登录程序。要求：建立一个登录窗口,要求输入密码。设定密码为“basic1234”(不区分大小写);若密码正确,显示“祝贺你,成功登录!”;若密码不正确,显示“对不起,密码错误,无法登录!”，并统计出错次数，当输入超过3次时，则退出系统。 Private Sub Command1_Click()

If LCase(Text2.Text) = \ MsgBox \祝贺你，成功登录！\ Else

MsgBox (\对不起，口令错误，无法登录！\ n = n + 1

Text2.Text = \ Text2.SetFocus

If n >= 3 Then Unload Me '也可以用End End If End Sub

Private Sub Text1_LostFocus()

If Len(Text1) <> 6 Or Not IsNumeric(Text1) Then MsgBox \帐号必须是6位数字！\ Text1 = \

Text1.SetFocus End If End Sub

分别输入年份和月份,根据输入数据显示该年该月有多少天? Private Sub Command1_Click() Dim y%,m%

y=InputBox(“输入年份：\m=InputBox(“输入月份：\

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Select Case m

Case 1,3,5,7,8,10,12

MsgBox y & “年” & m & “月有31天！” Case 4,6,9,11

MsgBox y & “年” & m & “月有30天！” Case 2

If y mod 400=0 or y mod 4 _ =0 and y mod 100<> 0 Then MsgBox y & “年” & m & “月有29天！”

Else

MsgBox y & “年” & m & “月有28天！”

End If Case Else

Magbox “输入错误，月份应该是1-12之间！” End Select End Sub

求1+2+3+……+100的值 方法一：

Private Sub Command1_Click() Dim i%, sum% sum = 0

For i = 1 To 100 sum = sum + i Next i

Print \的和是：\End Sub 方法二：

Private Sub Form_Click() Dim i%, sum% sum = 0 i = 1

Do While i <= 100 sum = sum + i i = i + 1 Loop

Print \的和是：\End Sub

求任意数的阶乘

Private Sub Command2_Click() Dim i%, n%, sum# sum = 1

n = Val(InputBox(\请输入阶乘数“\For i = 1 To n

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sum = sum * i Next

Print n; \的阶乘为\End Sub

输入若干个学生的成绩，求总分、平均分。输入时以-1作为结束标记。 Private Sub Command1_Click()

Dim n%, i%, sum%, max%, mark%, aver! mark = Val(InputBox(\请输入成绩\Do While mark <> -1 Print mark

If max < mark Then max = mark sum = sum + mark n = n + 1

mark = Val(InputBox(\请输入成绩\Loop

aver = sum / n

Print \总分为：\Print \平均为：\Print \最高分为：\End Sub

找出1~100之间所有能被3整除并且个位数字为2的数。 Private Sub Command1_Click()

Dim i%

For i = 1 To 100

If i Mod 3 = 0 And i Mod 10 = 2 Then Print i End If Next End Sub

输入一字符串，统计字母 “a”（包括大小写）的个数。 Private Sub Command1_Click() Dim i%, s$, ch$, n%

s = InputBox(\请输入一串字符串：\Print \字符串为：\n = 0

For i = 1 To Len(s) ch = Mid(s, i, 1)

If LCase(ch) = \Next

Print \字符a的个数为：\

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