1-代码之基础语法

计算每年的定存 

Module Module1
    Sub Main()
        Dim amount, prin As Decimal
        Dim rate As Double
        Dim year As Integer
        Dim output As String
        prin = 1000.0
        rate = 0.05
        output = "year" & vbTab & "Amount on deposit" & vbCrLf
        For year = 1 To 10
            amount = prin * (1 + rate) ^ year
            output &= year & vbTab & String.Format("{0:C}", amount) & vbCrLf
        Next
        MessageBox.Show(output, "comp interest", MessageBoxButtons.OK, MessageBoxIcon.Information)
    End Sub
End Module

 ＠String.Format()语法:    String.Format(  {index[,alignment][:formatString]}   )
  index--索引组件:   
  必选．“索引”组件（也叫参数说明符）是一个从   0   开始的数字，可标识值列表中对应的元素。也就是说，参数说明符为   0   的格式项格式化列表中的第一个值，参数说明符为   1   的格式项格式化列表中的第二个值，依次类推。   通过指定相同的参数说明符，多个格式项可以引用值列表中的同一个元素。例如，通过指定类似于“{0:X}   {0:E}   {0:N}”的源字符串，可以将同一个数值格式化为十六进制、科学表示法和数字格式。   每一个格式项都可以引用所有的参数。例如，如果有三个值，则可以通过指定类似于“{1}   {0}   {2}”的源字符串来格式化第二、第一和第三个值。格式项未引用的值会被忽略。如果参数说明符指定了超出值列表范围的项，将导致运行时异常。   
    
  alignment--对齐组件:  
  可选．“对齐”组件是一个带符号的整数，指示首选的格式化字段宽度。如果“对齐”值小于格式化字符串的长度，“对齐”会被忽略，并且使用格式化字符串的长度作为字段宽度。如果“对齐”为正数，字段的格式化数据为右对齐；如果“对齐”为负数，字段的格式化数据为左对齐。如果需要填充，则使用空白。如果指定“对齐”，就需要使用逗号。   
    
  formatString--格式字符串组件:  
  可选．“格式字符串”组件由标准或自定义格式说明符组成。如果不指定“格式字符串”，则使用常规（“G”）格式说明符。如果指定“格式说明符”，需要使用冒号。  
   
  处理顺序:  
  如果要格式化的值是   null（在   Visual   Basic   中为   Nothing），则返回空字符串   ("")。  
  如果要格式化的类型实现   ICustomFormatter   接口，则调用   ICustomFormatter.Format   方法。  
  如果前面的步骤未格式化类型，并且该类型实现   IFormattable   接口，则调用   IFormattable.ToString   方法。  
  如果前面的步骤未格式化类型，则调用该类型的   ToString   方法（从   Object   类继承而来）。  
  前面的步骤执行完毕之后应用对齐。  
   
  代码示例:    
  Dim   FormatString1   As   String   =   String.Format("{0:dddd   MMMM}",   DateTime.Now)  
  Dim   FormatString2   As   String   =   DateTime.Now.ToString("dddd   MMMM")   
  String.Format("{0:####}",123), 结果: 123       
  String.Format("{0,8:G}  ",123), 结果: 123_ _ _ _ _   (下划线表示填充空格)

==================================================================================
标签移动效果
    'tips: u need a label and 2 button
    Dim step1 As Integer
    Public Sub mymove() 'move
        Dim disX = CInt(Rnd() * 50 * step1)
        Dim disY = CInt(Rnd() * 50 * step1)
        Randomize()
        Label1.Location = New Point(Label1.Left + disX, Label1.Top + disY)
 'cannot use move method as vb6
        If Label1.Top + 1.5 * Label1.Height > Me.Height Then
            step1 = -1
        ElseIf Label1.Top < 0 Then
            step1 = 1
        End If
    End Sub

    Private Sub Form1_Load(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles MyBase.Load
        step1 = 1 'initialization
        Label1.Text = "hello world"
        Timer1.Enabled = False
    End Sub

    Private Sub Button1_Click(ByVal sender As Object, ByVal e As System.EventArgs) Handles Button1.Click
        Timer1.Enabled = False 'stop move
    End Sub

    Private Sub Button2_Click(ByVal sender As Object, ByVal e As System.EventArgs) Handles Button2.Click
        Timer1.Interval = 200 'set the interval time of timer event
        Timer1.Enabled = True
    End Sub

    Private Sub Timer1_Tick(ByVal sender As Object, ByVal e As System.EventArgs) Handles Timer1.Tick
        Call mymove() 'call the move function
    End Sub

==================================================================================

复合运算
 'tips: u will c the result in the output form
    Private Sub Button1_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button1.Click
        Dim a, b As Single
        a = 28 : b = 8
        Debug.WriteLine("a=" & a & "b=" & b)
        a += b
        Debug.WriteLine("a+=b=" & a)
        a = 28 : b = 8
        a = -b
        Debug.WriteLine("a-=b=" & a)
        a = 28 : b = 8
        a *= b
        Debug.WriteLine("a*=b=" & a)
        a = 28 : b = 8
        a /= b
        Debug.WriteLine("a/=b=" & a)
        a = 28 : b = 8
        a /= b
        Debug.WriteLine("a/=b" & a)
    End Sub
==================================================================================

日期函数
    'tips: u need a label and a button
    Private Sub Form1_Load(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles MyBase.Load
        Dim t As Date = Now
        Label1.Text = Year(t) & "年" & Month(t) & "月" _
                        & Microsoft.VisualBasic.Day(t) & "日" _
                        & Hour(t) & "点" & Minute(t) & "分" & Second(t) & "秒"
    End Sub
==================================================================================

枚举类型
   'tips: u need a button
    Public Enum workDays
        Sunday = 1
        Monday
        Tuesday
        Wednesday
        Thursday
        Friday
        Saturday
        invalid = -1
    End Enum

    Private Sub Button1_Click(ByVal sender As Object, ByVal e As System.EventArgs) Handles Button1.Click
        Dim MyDay As workDays
        MyDay = Weekday(Now()) 'use the weekday function
        If MyDay = workDays.Saturday Or MyDay = workDays.Sunday Then
            MsgBox("It′s the weekend.Invalid work day!", MsgBoxStyle.Critical, "alert")
        Else
            MsgBox("It′s a workday.To the weekend, there are " & workDays.Saturday - MyDay & " days left!", MsgBoxStyle.Information, "information")
        End If
    End Sub
==================================================================================

循环语句
    'tips: u need a button
    Private Sub Button1_Click(ByVal sender As Object, ByVal e As System.EventArgs) Handles Button1.Click
        Dim ch As Char
        Dim msg As String
        Const exitCh = "?"

        Dim counter As Short = 0
        msg = "enter a character:"
        ch = InputBox(msg, "input")
        While ch <> exitCh
            counter = counter + 1
            ch = InputBox$(msg)
        End While
        MsgBox("number of character entered:" & counter)
    End Sub
==================================================================================
条件语句-绝对值
    'tips: u need a button
    Private Sub Button1_Click(ByVal sender As Object, ByVal e As System.EventArgs) Handles Button1.Click
        Dim X, absX As Integer
        Dim msg As String
        X = Val(InputBox("pls input a number", "input"))
        If X < 0 Then absX = -1 * X
        MsgBox(X & "的绝对值: " & absX, MsgBoxStyle.Information, "result")
    End Sub
==================================================================================
条件语句-计税
    'tips: u need a button
    Private Sub Button1_Click(ByVal sender As Object, ByVal e As System.EventArgs) Handles Button1.Click
        Dim price, qty, total, tax, pay As Integer
        Dim tax_rate As Single
        Dim msg As String

        price = Val(InputBox("pls input the price/unit", "input"))
        qty = Val(InputBox("pls input the quantity：", "input"))
        total = price * qty
        If total > 100 Then
            tax_rate = 0.05
        Else
            tax_rate = 0
        End If
        tax = total * tax_rate
        pay = total + tax
        msg = "price:" & vbTab & vbTab & price & vbNewLine _
            & "quantity:" & vbTab & vbTab & qty & vbNewLine _
            & "--------------------------------" & vbNewLine _
            & "total price:" & vbTab & total & vbNewLine _
            & "tax:" & vbTab & vbTab & tax & vbNewLine _
            & "--------------------------------" & vbNewLine _
            & "you should pay:" & vbTab & pay & vbNewLine
        MsgBox(msg, MsgBoxStyle.Information, "account")
    End Sub

==================================================================================
IIF
    'tips: u need a button
    Private Sub Button1_Click(ByVal sender As Object, ByVal e As System.EventArgs) Handles Button1.Click
        Dim num1, num2 As Integer
        Dim result As String
        Dim msg As String
        num1 = InputBox("pls input number 1", "input")
        num2 = InputBox("pls input number 2", "input")
        result = IIf(num1 > num2, "大于", IIf(num1 = num2, "等于", "小于"))
        msg = "num1=" & num1 & vbNewLine _
            & "num2=" & num2 & vbNewLine _
            & "=================" & vbNewLine _
            & num1 & result & num2
        MsgBox(msg, MsgBoxStyle.Information, "compare")
    End Sub

==================================================================================
SELECT语句
    'tips: u need a button
    Private Sub Button1_Click(ByVal sender As Object, ByVal e As System.EventArgs) Handles Button1.Click
        Dim ch As Char
        Dim inputStr, msg As String
        Dim i As Integer

        inputStr = InputBox("pls input some characters")
        For i = 1 To Len(inputStr)
            ch = Mid(inputStr, i, 1)
            Select Case ch
                Case "a" To "z", "A" To "Z"
                    msg &= ch & "是字母字符" & vbNewLine
                Case "0" To "9"
                    msg &= ch + "是数字字符" & vbNewLine
                Case Else
                    msg &= ch + "是其他字符" & vbNewLine
            End Select
        Next
        MsgBox(msg, MsgBoxStyle.Information, "result")
    End Sub

==================================================================================
SELECT语句
    'tips: u need a button
    Private Sub Button1_Click(ByVal sender As Object, ByVal e As System.EventArgs) Handles Button1.Click
        Dim msg, userinput
        userinput = InputBox("pls input a character", "input")
        If Not IsNumeric(userinput) Then
            If Len(userinput) <> 0 Then
                Select Case Asc(userinput)
                    Case 65 To 90
                        msg = "你输入的是大写英文字母'"
                        msg = msg & Chr(Asc(userinput)) & "'."
                    Case 97 To 122
                        msg = "你输入的是小写英文字母'"
                        msg = msg & Chr(Asc(userinput)) & "'."
                    Case Else
                        msg = "你没有输入英文字母或数字字符"
                End Select
            End If
        Else
            Select Case CDbl(userinput)
                Case 1, 3, 5, 6, 9
                    msg = userinput & "是一个奇数."
                Case 0, 2, 4, 6, 8
                    msg = userinput & "是一个偶数."
                Case Else
                    msg = "你输入的数字超出了"
                    msg = msg & "所允许的范围."
            End Select
        End If
        MsgBox(msg, MsgBoxStyle.Information, "result")
    End Sub

==================================================================================
FOR循环
    'tips: u need a button
    Private Sub Button1_Click(ByVal sender As Object, ByVal e As System.EventArgs) Handles Button1.Click
        Dim i, s As Integer
        Dim msg As String

        s = 0
        For i = 1 To 100 Step 2
            s = s + i
        Next i
        msg &= "1+3+5+...+99=" & s
        MsgBox(msg, MsgBoxStyle.Information, "result")
    End Sub

==================================================================================
FOR循环--阶乘
    'tips: u need a button
    Private Sub Button1_Click(ByVal sender As Object, ByVal e As System.EventArgs) Handles Button1.Click
        Dim n, k, i As Long
        n = InputBox("enter n:")
        k = 1
        For i = 1 To n
            k = k * i
        Next i
        MsgBox(Str(n) & "!=" & Str(k), MsgBoxStyle.Information, "result")
    End Sub

==================================================================================
DO。。WHILE循环--求自然对数E
    'tips: u need a button
    Private Sub Button1_Click(ByVal sender As Object, ByVal e As System.EventArgs) Handles Button1.Click
        Dim i%, n&, t!, e1!
        e1 = 0 : i = 0 : n = 1 : t = 1
        Do While t > 0.00001
            e1 = e1 + t         '累加和
            i = i + 1
            n = n * i           '连乘，求阶乘
            t = 1 / n           '计数第i项值
        Loop
        MsgBox("求e时计算了" & Str(i) & "项的和是" & Str(e1), MsgBoxStyle.Information, "result")
    End Sub

==================================================================================
数组--高于平均分的人数
    'tips: u need a button
    Private Sub Button1_Click(ByVal sender As Object, ByVal e As System.EventArgs) Handles Button1.Click
        Const N As Integer = 3
        Dim mark(N) As Integer
        Dim aver!, overn%, i%
        aver = 0
        For i = 1 To N
            mark(i) = InputBox("输入" & i & "位学生的成绩")
            aver = aver + mark(i)
        Next
        aver = aver / N
        overn = 0
        For i = 1 To N
            If mark(i) > aver Then overn = overn + 1
        Next
        MsgBox("average mark:" & aver & ", above average:" & overn, MsgBoxStyle.Information, "result")
    End Sub

==================================================================================
数组嵌套
    'tips: u need a button
        Dim i As Short
 Dim msg As String
        Static Firstarray(4) As String
        For i = 0 To 4
            Firstarray(i) = Chr(i + 65)
        Next i
        Static Secondarray(4) As Short
        For i = 0 To 4
            Secondarray(i) = i + 10
        Next i
        Static Thirdarray(1)
        Thirdarray(0) = Firstarray
        Thirdarray(1) = Secondarray
       
        For i = 0 To 4
            msg &= Thirdarray(0)(i) & vbTab
        Next i
        msg &= vbCrlf
        For i = 0 To 4
           msg &= Thirdarray(1)(i) & vbTab
        Next i
 msg &= vbCrlf
        MsgBox(msg, MsgBoxStyle.Information, "result")

==================================================================================
数组函数
    'tips: u need a button
        Dim test(10), i As Integer
 Dim msg As String
        For i = 0 To 10
            test(i) = i
            msg &= Str(test(i)) & vbTab
        Next i
        Erase test   'use the erase function
        msg &= vbCrlf & "erase test():" & vbCrlf
        ReDim test(12)
        For i = 0 To 12
            msg &= Str(test(i)) & vbTab
        Next i
 msg &= vbCrlf
        MsgBox(msg, MsgBoxStyle.Information, "result") 

==================================================================================
三维数组
    'tips: u need a button
        Dim i, j, k, a(1, 2, 1) As Short
 Dim msg As String
        For i = 0 To 1
            For j = 0 To 2
                For k = 0 To 1
                    a(i, j, k) = i + j + k
                Next k
            Next j
        Next i
        For i = 0 To 1
            For j = 0 To 2
                For k = 0 To 1
                    msg &= "  " & "a(" & Str(i) & "," & Str(j) & "," & Str(k) & ")=" & Str(a(i, j, k)) & vbCrlf
                Next
            Next
        Next
        MsgBox(msg, MsgBoxStyle.Information, "result") 

==================================================================================
数组--for each
    'tips: u need a button
        Dim arr(10), Arr_elem, Sum
        Dim i As Short
 Dim msg As String
        For i = 0 To 10
            arr(i) = Int(Rnd() * 100)
        Next i
        For Each Arr_elem In arr
            If Arr_elem > 50 Then
                msg &= Str(Arr_elem) & vbTab
                Sum = Sum + Arr_elem
            End If
            If Arr_elem > 95 Then Exit For
        Next Arr_elem
  msg = mid(msg,1,len(msg)-1)
        MsgBox(  msg & "=" & Str(Sum), MsgBoxStyle.Information, "result")  
  
==================================================================================
数组--统计字母个数
    'tips: u need a button
        Dim a%(26), c$, inputStr$, le%, i%, j%, msg$
        inputStr=inputbox("pls input some characters")
        le = Len(inputStr)                    '求字符串的长度
        For I = 1 To le
            c = UCase(Mid(inputStr, i, 1))    '取一个字符，转换成大写
            If c >= "A" And c <= "Z" Then
                j = Asc(c) - 65 + 1                '将A~Z大写字母转换成1~26的下标
                a(j) = a(j) + 1                    '对应数组元素加1
            End If
        Next i
        For j = 1 To 26                            '输出字母及其出现的次数
            If a(j) > 0 Then msg &= " " & Chr(j + 64) & "=" & a(j) & vbTab
        Next j 
        MsgBox(  "frequency of characters:" & msg, MsgBoxStyle.Information, "result")

==================================================================================
数组--分裂、合并
    'tips: u need a textbox and 2 button
    Dim a() As String
    '输入数据，去除非法数字
    Private Sub TextBox1_KeyPress(ByVal sender As Object, ByVal e As System.Windows.Forms.KeyPressEventArgs) Handles TextBox1.KeyPress
         Select Case e.KeyChar
            Case "0" To "9", ",", ".", "-"
                '0~9,逗号，小数点，负号为有效数字串，可以继续输入
            Case Else
                '输入非数字字符，去除非法字符，再输入
                e.Handled =true
        End Select
    End Sub

    '输入的内容按逗号为分隔符分离，结果放入a字符数组中
    Private Sub Button1_Click(ByVal sender As Object, ByVal e As System.EventArgs) Handles Button1.Click
        Dim temp As String, i As Integer
        Dim msg As String
        temp = Replace(TextBox1.Text, ",,", ",")   '调用Replace函数去除出现的连续分隔符
        a = Split(temp, ","  '调用Split函数将Text1的内容按逗号为分隔符分离，结果放入a数组中
        For i = 0 To UBound(a)
            msg &= a(i) & space(2)
        Next i
        MsgBox( msg, MsgBoxStyle.Information, "after split")
    End Sub

    '将数组a中各元素合并
    Private Sub Button2_Click(ByVal sender As Object, ByVal e As System.EventArgs) Handles Button2.Click
  Dim msg As String
  msg = Join(a, "|")
  MsgBox( msg, MsgBoxStyle.Information, "after join together")
    End Sub

==================================================================================
数组排序
    'tips: u need a  button
        Dim iA%(10), iMin%, n%, i%, j%, t%, k%, msg$
        iA(1) = 8 : iA(2) = 6 : iA(3) = 9 : iA(4) = 3 : iA(5) = 2 : iA(6) = 7
        n = 6
        For i = 1 To n - 1                       '进行n-1轮比较
            For j = n To i + 1 Step -1           '从n~I个元素进行两两比较
                If iA(j) < iA(j - 1) Then        '若次序不对，则马上进行交换位置
                    t = iA(j)
                    iA(j) = iA(j - 1)
                    iA(j - 1) = t
                End If
            Next j                               '出了内循环，一轮排序结束，最小数已冒到最上面
        Next i
        For i = 1 To 6
            msg &= iA(i) & vbTab
        Next i
 MsgBox( msg, MsgBoxStyle.Information, "after sort")

==================================================================================
新增数组元素
    'tips: u need a  button
        Dim a%(10), I%, k%, addnum%, msg$
        For I = 1 To 9                      'initialize the sorted array 
            a(I) = (I - 1) * 3 + 1
        Next I
        addnum = val(inputbox("pls input the number u wanna seek(1-25)", "input"))
        For k = 1 To 9                      'find the index of seeknum
            If addnum < a(k) Then Exit For
        Next k
        For I = 9 To k Step -1              'move items
            a(I + 1) = a(I)
        Next I
        a(k) = addnum                       'insert
        For I = 1 To 10
            msg &= a(I) & vbTab
        Next
        MsgBox( msg, MsgBoxStyle.Information, "result")

==================================================================================
结构体
    'tips: u need a  button
    Public Structure mail              '定义结构类型
        Public num As Short
        Public name As String
        Public title As String
        Public addr As String
        Public zip As Integer
        Public tel As String
    End Structure

    Private Sub Form1_Load(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles MyBase.Load
        Dim member1 As mail            '定义结构变量
        Dim msg As String
      
        member1.num = val(inputbox("pls input number","input"))  '对结构各成员赋值
        member1.name = inputbox("pls input name","input")
        member1.title =inputbox("pls input title","input")
        member1.addr = inputbox("pls input address","input")
        member1.zip = val(inputbox("pls input zip code","input"))
        member1.tel = inputbox("pls input the telphone","input")
                '通过结构变量分别引用结构的各个成员
        msg = "number" & vbTab & "name" & vbTab & "title" & vbTab _
         & "address" & vbTab & "zip" & vbTab & "tel" & vbCrlf _
         & "-----------------------------------------" _
         & "-----------------------------------------" & vbCrlf _
         & member1.num & vbTab & member1.name & vbTab & member1.title & vbTab _
         & member1.addr & vbTab & member1.zip & vbTab & member1.tel
        MsgBox( msg, MsgBoxStyle.Information, "result")
    End Sub

==================================================================================
结构体数组
   Const MAX_MEM = 2
    Private Structure mail
        Public num As Short
        Public name As String
        Public title As String
        Public addr As String
        Public zip As Integer
        Public tel As String
    End Structure

    Private Sub Form1_Load(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles MyBase.Load
        Dim list(MAX_MEM) As mail             'define a array
        Dim msg As String
        Dim i As Short
        '从键盘上一次录入每个会员的各数据项的数据
        For i = 0 To MAX_MEM
         list(i).num = val(inputbox("pls input number","input"))
         list(i).name = inputbox("pls input name","input")
         list(i).title =inputbox("pls input title","input")
         list(i).addr = inputbox("pls input address","input")
         list(i).zip = val(inputbox("pls input zip code","input"))
         list(i).tel = inputbox("pls input the telphone","input")
        Next i
        '输出数据
        msg = "number" & vbTab & "name" & vbTab & "title" & vbTab _
         & "address" & vbTab & "zip" & vbTab & "tel" & vbCrlf _
         & "-----------------------------------------" _
         & "-----------------------------------------" & vbCrlf
        '依次显示
        Dim spa As String = "    "
        For i = 0 To MAX_MEM
         msg &= list(i).num & vbTab & list(i).name & vbTab & list(i).title & vbTab _
          & list(i).addr & vbTab & list(i).zip & vbTab & list(i).tel & vbCrlf
        Next
        MsgBox( msg, MsgBoxStyle.Information, "result")
    End Sub

==================================================================================
集合
 Dim i As Short
 Dim msg As String
        Dim myname As New Collection()
        Dim x
        For i = 1 To 10
            myname.Add(item:="name" & i, key:="key#" & i)
            msg &=myname(i) & " "
        Next i
        msg &=  vbcrlf
       
        myname.Remove(3)
        myname.Remove("key#9")
       
        msg &= "after delete items" & vbcrlf
        For i = 1 To 8
             msg &=myname(i) & " "
        Next i
       MsgBox( msg, MsgBoxStyle.Information, "result")

==================================================================================
集合
        Dim anytype As New Collection()
        Dim x, a As Object
        x = "Visual Basic.NET"
        anytype.Add(x)
        x = 246
        anytype.Add(x)
        anytype.Add(Now)
        anytype.Add(9876.5436)
        anytype.Add("微型计算机")
        For Each a In anytype
           msgbox(a)
        Next a