Imports System.Data.OleDb
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Public Class Parking
Private Sub Parking_Load(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles MyBase.Load
Now_Timer.Enabled = True
End Sub
Private Sub Now_Timer_Tick(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Now_Timer.Tick
Now_Time_Label.Text = "当前时间：" Date.Now
End Sub
Private Sub Enter_Button_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Enter_Button.Click
'定义一个OLEDB连接字符串
Dim conStr As String = "Provider=Microsoft.Jet.OLEDB.4.0; Data Source=F:\test\test.mdb"
'实例化OLEDB连接
Dim con As OleDbConnection = New OleDbConnection(conStr)
Dim sql As New System.Text.StringBuilder
'定义数据库插入语句
sql.Append("insert into Time_billing([Car_Num],[Enter_Time])")
sql.Append("values('" Trim(Car_Num_Text.Text) "','" Date.Now "')")
'打开数据库链接
con.Open()
'定义执行命令
Dim cmd As New System.Data.OleDb.OleDbCommand(sql.ToString, con)
'执行命令
cmd.ExecuteNonQuery()
'关闭数据库链接
con.Close()
MsgBox("提交成功！")
End Sub
Private Sub Leave_Button_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Leave_Button.Click
Dim Time_Length As Double
Dim Pack_Fee As Double
Dim Enter_time As Date
Dim Leave_time As Date
Dim conStr As String = "Provider=Microsoft.Jet.OLEDB.4.0; Data Source=F:\test\test.mdb"
Dim con As OleDbConnection = New OleDbConnection(conStr)
Dim selSql As New System.Text.StringBuilder
Dim inSql As New System.Text.StringBuilder
Dim upSql As New System.Text.StringBuilder
Dim delSql As New System.Text.StringBuilder
Dim dr As OleDbDataReader
con.Open()
'SQL拼接过程中最后不需要有分号
'在赋值时，读取字段值时必须使用在数据库客户端查询时显示的字段名
selSql.Append("select")
selSql.Append(" Enter_Time")
selSql.Append(" from [Time_billing]")
selSql.Append("where Car_Num = '").Append(Trim(Car_Num_Text.Text)).Append("'")
Dim selcmd As New OleDb.OleDbCommand(selSql.ToString, con)
dr = selcmd.ExecuteReader()
If dr.Read() Then
Enter_time = dr("Enter_Time")
Leave_time = Date.Now
Else
MsgBox("木有数据！")
End If
Enter_Time_Text.Text = Enter_time
Leave_Time_Text.Text = Leave_time
'求时间差
Time_Length = Math.Round(DateDiff(DateInterval.Minute, Enter_time, Leave_time) / 60, 2)
Pack_Fee = Time_Length * 5
Pack_Fee_Text.Text = Pack_Fee
inSql.Append("update [Time_billing]")
inSql.Append(" set [Leave_Time] = '").Append(Trim(Leave_Time_Text.Text)).Append("'")
inSql.Append(" ,[Packing_Fee] = '").Append(Pack_Fee).Append("'")
inSql.Append("where Car_Num = '").Append(Trim(Car_Num_Text.Text)).Append("'")
Dim incom As New OleDb.OleDbCommand(inSql.ToString, con)
incom.ExecuteNonQuery()
'con.Close()
MsgBox("结算完成！")
'con.Open()
upSql.Append("insert into Time_billing_History([Car_Num],[Enter_Time],[Leave_Time],[Packing_Fee])")
upSql.Append(" select")
upSql.Append(" [Car_Num]")
upSql.Append(",[Enter_Time]")
upSql.Append(",[Leave_Time]")
upSql.Append(",[Packing_Fee]")
upSql.Append(" from [Time_billing]")
upSql.Append("where [Car_Num] = '").Append(Trim(Car_Num_Text.Text)).Append("'")
Dim upcom As New OleDb.OleDbCommand(upSql.ToString, con)
upcom.ExecuteNonQuery()
delSql.Append("delete")
delSql.Append(" from")
delSql.Append(" [Time_billing]")
delSql.Append(" where [Car_Num] = '").Append(Trim(Car_Num_Text.Text)).Append("'")
Dim delcom As New OleDb.OleDbCommand(delSql.ToString, con)
delcom.ExecuteNonQuery()
con.Close()
End Sub
Private Sub Clear_Button_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Clear_Button.Click
Car_Num_Text.Clear()
Enter_Time_Text.Clear()
Leave_Time_Text.Clear()
Pack_Fee_Text.Clear()
End Sub
End Class
checklogin = "select 用户名 from 用户表"
最好改为:
checklogin = "select * from 用户表 where 用户名 = '" textbox1.text "'"
在后面判断reader是否有记录就可以知道用户名是否存在
Dim sFileName As String
Dim Search
Private Sub dateTimeMenu_Click()
Text1.Text = Now
End Sub
Private Sub deleteMenu_Click()
Text1.Text = Left(Text1.Text, Text1.SelStart) + Mid(Text1.Text, Text1.SelStart + Text1.SelLength + 1)
End Sub
Private Sub findMenu_Click()
Search = InputBox("请输入要查找的字词：")
Dim Where1 '获取需要查找的字符串变量
Text1.SetFocus '文本框获得焦点，以显示所找到的内容Search = InputBox("请输入要查找的字词：")
Where1 = InStr(Text1.Text, Search) '在文本中查找字符串
If Where1 Then
'若找到则设置选定的起始位置并使找到的字符串高亮
Text1.SelStart = Where1 - 1
Text1.SelLength = Len(Search)
' Me.Caption = Where1 '测试用
'否则给出提示
Else: MsgBox "未找到所要查找的字符串。", vbInformation, "提示"
End If
End Sub
Private Sub findNextMenu_Click()
Dim Where2
Dim StartMe As Integer '查找的起始位置变量
Text1.SetFocus '文本框获得焦点
StartMe = Text1.SelLength + Text1.SelStart + 1 '给变量赋值
Where2 = InStr(StartMe, Text1.Text, Search) '令其从上次找到的地方找起
If Where2 Then
Text1.SelStart = Where2 - 1
Text1.SelLength = Len(Search)
Else: MsgBox "未找到所要查找的字符串.", vbInformation, "提示"
End If
End Sub
Private Sub aboutMenu_Click()
MsgBox Space(2) "文本编辑器版本号1.0" Chr(13) "由西南财经大学天府学院" Chr(13) Space(5) "肖忠 开发" Chr(13) Space(2) "copyright:天府学院"
End Sub
Private Sub allMenu_Click()
Text1.SelStart = 0
Text1.SelLength = Len(Text1.Text)
End Sub
Private Sub backcolorMenu_Click() '设置背景色代码
Form1.CommonDialog1.Action = 3
Text1.BackColor = Form1.CommonDialog1.Color
End Sub
Private Sub colorMenu_Click() '改变文字颜色代码
Form1.CommonDialog1.Action = 3
Text1.ForeColor = Form1.CommonDialog1.Color
End Sub
Private Sub cutMenu_Click()
Clipboard.SetText Text1.SelText
Text1.Text = Left(Text1.Text, Text1.SelStart) + Mid(Text1.Text, Text1.SelStart + Text1.SelLength + 1)
End Sub
Private Sub exitMenu_Click()
End
End Sub
Private Sub fontMenu_Click() '字体菜单代码
Form1.CommonDialog1.Flags = 3 Or 256
Form1.CommonDialog1.Action = 4
If Len(Form1.CommonDialog1.FontName) = 0 Then
Form1.Text1.FontName = "宋体"
Else
Form1.Text1.FontName = Form1.CommonDialog1.FontName
End If
Form1.Text1.FontSize = Form1.CommonDialog1.FontSize
If Form1.CommonDialog1.FontBold = True Then
Form1.Text1.FontBold = True
Else
Form1.Text1.FontBold = False
End If
If Form1.CommonDialog1.FontItalic = True Then
Form1.Text1.FontItalic = True
Else
Form1.Text1.FontItalic = False
End If
Text1.ForeColor = Form1.CommonDialog1.Color
End Sub
Private Sub Form_Load()
Form1.Text1.Width = Form1.Width - 130
Form1.Text1.Height = Form1.Height
End Sub
Private Sub Form_Resize()
Form1.Text1.Width = Form1.Width - 130
Form1.Text1.Height = Form1.Height
End Sub
Private Sub help1Menu_Click()
Form1.CommonDialog1.HelpCommand = cdlHelpForceFile
Form1.CommonDialog1.HelpFile = "c:\windows\system32\winhelp.hlp"
CommonDialog1.ShowHelp
End Sub
Private Sub newMenu_Click()
If Len(Trim(Text1.Text)) = 0 Then
Form1.Caption = "我的记事本" "--" "未命名"
sFileName = "未命名"
Text1.FontSize = 15
Text1.FontName = "宋体"
Text1.Text = ""
Else
Call saveAsMenu_Click
Form1.Caption = "我的记事本" "--" "未命名"
sFileName = "未命名"
Text1.FontSize = 15
Text1.FontName = "宋体"
Text1.Text = ""
End If
End Sub
Private Sub openMenu_Click() '打开文件代码
If Len(Trim(Text1.Text)) = 0 Then
Form1.Caption = "我的记事本"
Form1.CommonDialog1.Filter = "文本文件|*.txt"
Form1.CommonDialog1.Flags = 4096
Form1.CommonDialog1.Action = 1
If Len(Form1.CommonDialog1.FileName) 0 Then
sFileName = Form1.CommonDialog1.FileName
Form1.Caption = Form1.Caption "--" Form1.CommonDialog1.FileTitle
Open sFileName For Input As #1
Text1.FontSize = 15
Text1.FontName = "宋体"
Do While Not EOF(1)
Line Input #1, Text$
All$ = All$ + Text$ + Chr(13) + Chr(10)
Loop
Text1.Text = All
Close #1
End If
Else
Call saveAsMenu_Click
Form1.Caption = "我的记事本"
Form1.CommonDialog1.Filter = "文本文件|*.txt"
Form1.CommonDialog1.Flags = 4096
Form1.CommonDialog1.Action = 1
If Len(Form1.CommonDialog1.FileName) 0 Then
sFileName = Form1.CommonDialog1.FileName
Form1.Caption = Form1.Caption "--" Form1.CommonDialog1.FileTitle
Open sFileName For Input As #1
Text1.FontSize = 15
Text1.FontName = "宋体"
Do While Not EOF(1)
Line Input #1, Text$
All$ = All$ + Text$ + Chr(13) + Chr(10)
Loop
Text1.Text = All
Close #1
End If
End If
End Sub
Private Sub pasteMenu_Click() '粘贴菜单代码
Text1.Text = Left(Text1.Text, Text1.SelStart) + Clipboard.GetText() + Mid(Text1.Text, Text1.SelStart + Text1.SelLength + 1)
End Sub
Private Sub printMenu_Click()
Form1.CommonDialog1.ShowPrinter
For i = 1 To CommonDialog1.Copies
Printer.Print Text1.Text
Printer.Print Text1.Text
Next
Printer.EndDoc
End Sub
Private Sub saveAsMenu_Click() '另存为菜单代码
If Len(Trim(Text1.Text)) 0 Then
Form1.CommonDialog1.DialogTitle = "保存文件"
Form1.CommonDialog1.InitDir = "D:\"
Form1.CommonDialog1.Filter = "文本文件|*.txt"
Form1.CommonDialog1.Flags = 2
Form1.CommonDialog1.ShowSave
If Len(Form1.CommonDialog1.FileName) 0 Then
sFileName = Form1.CommonDialog1.FileName
Open sFileName For Output As #1
whole$ = Text1.Text
Print #1, whole
Close #1
End If
End If
End Sub
Private Sub saveMenu_Click()
If Len(Trim(Text1.Text)) 0 Then
Form1.CommonDialog1.DialogTitle = "保存文件"
Form1.CommonDialog1.InitDir = "D:\"
Form1.CommonDialog1.FileName = "新建文本"
Form1.CommonDialog1.Filter = "文本文件|*.txt"
Form1.CommonDialog1.Flags = 2
Form1.CommonDialog1.ShowSave
If Len(Form1.CommonDialog1.FileName) 0 Then
sFileName = Form1.CommonDialog1.FileName
Open sFileName For Output As #1
whole$ = Text1.Text
Print #1, whole
Close #1
End If
End If
End Sub
Private Sub statusMenu_Click()
End Sub
Imports System
Module Program
Sub Main()
Dim n As Integer
n=6
Console.WriteLine("{0}!={1}",n,fact(n))
n=10
For i As Integer=1 To n
Console.Write("{0}{1}",fibo(i),IIF(n=i,vbCrLf,","))
Next
Console.Write("按任意键继续。。。 ")
Console.ReadKey(True)
End Sub
' 递归算阶乘
Function fact(n As Long) As Long
If 0=n OrElse 1=n Then Return 1
Return n*fact(n-1)
End Function
' 递归算斐波那契数列
Function fibo(n As Long) As Long
If 1=n OrElse 2=n Then Return 1
Return fibo(n-1)+fibo(n-2)
End Function
End Module
又碰你了……
好吧，这回代码改进了：
Code:
'我们需要几个基本控件：
'TextBox1 、TextBox2、TextBox3 、TextBox4分别为“原文”、“输入”、“准确率”、“用时”的显示文本框。
'Button1、Button2、Button3分别为“生成原文”、“开始输入”、“结束”三个功能性按钮。
'Timer1是计时器（Timer）组件。
'有几个为了不出错，需要把Enabled属性设为False的组件：TextBox1、TextBox2、Button3。
'下面是整体代码：（整个Form1.vb）
Public Class Form1
'声明几个需要的变量和随机器。
Dim i As Random = New Random '随即器
Dim TimeDate As Double = 0 '计时变量
Private Sub Button1_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button1.Click '生成原文按钮。
Dim k As Integer
Dim pText As String = ""
For si As Int16 = 1 To 30 '随即生成字符，添加到前面已声明的pText变量内。
k = i.Next(1, 26)
Select Case k '获取对应的字符。
Case 1
pText += "a"
Case 2
pText += "b"
Case 3
pText += "c"
Case 4
pText += "d"
Case 5
pText += "e"
Case 6
pText += "f"
Case 7
pText += "g"
Case 8
pText += "h"
Case 9
pText += "i"
Case 10
pText += "j"
Case 11
pText += "k"
Case 12
pText += "l"
Case 13
pText += "m"
Case 14
pText += "n"
Case 15
pText += "o"
Case 16
pText += "p"
Case 17
pText += "q"
Case 18
pText += "r"
Case 19
pText += "s"
Case 20
pText += "t"
Case 21
pText += "u"
Case 22
pText += "v"
Case 23
pText += "w"
Case 24
pText += "x"
Case 25
pText += "y"
Case 26
pText += "z"
End Select
Next
TextBox1.Text = pText
TextBox2.Text = ""
TextBox3.Text = ""
TextBox4.Text = ""
'处理文本内容。
End Sub
Private Sub Button2_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button2.Click '开始输入按钮。
If TextBox1.Text = "" Then
MsgBox("还未生成原文！") '如果前面未生成原文时的警告。
Else
'如果原文已有，将执行这些动作（即开始输入和准备）
TextBox2.Enabled = True
TextBox2.Select()
Timer1.Enabled = True
Button3.Enabled = True
Button1.Enabled = False
Button2.Enabled = False
End If
End Sub
Private Sub Timer1_Tick(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Timer1.Tick '计时器如果开始时的动作。
TimeDate += 1 / 10
End Sub
Private Sub Button3_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button3.Click '结束按钮。
Timer1.Enabled = False
Dim t As Double = TimeDate
TimeDate = 0
TextBox3.Text = t "秒"
Dim x As String, y As String
Dim i As Integer, s As Integer
s = 0
For i = 1 To Len(TextBox1.Text)
x = Mid(TextBox1.Text, i, 1)
y = Mid(TextBox2.Text, i, 1)
If x y Then
s = s + 1
End If
Next '寻找有几个错误。
'下面为计算正确率，使用Integer类型来约值。
Dim xi As Double = 1 - (s / 30)
Dim xiInt As Integer = xi * 100
TextBox4.Text = xiInt "%"
Button3.Enabled = False
Button1.Enabled = True
Button2.Enabled = True
End Sub
End Class
'到此结束，可以开始测试了。
'可以改进改代码后控件样式，以更方便使用。
基本的算法如下：
Class Program
Shared Sub Main()
Combine(Enumerable.Range(1, 8).ToArray(), 5)
End Sub
Private Shared Sub Combine(a() As Integer, n As Integer)
combine(a, 0, n, New Integer(n - 1){})
End Sub
Private Shared Sub combine(a() As Integer, m As Integer, n As Integer, b() As Integer)
If n=0 Then
For Each i As Integer In b
Console.Write(i " ")
Next i
Console.WriteLine()
Return
End If
For i As Integer = m To a.Length-n
b(b.Length-n) = a(i)
combine(a, i+1, n-1, b)
Next i
End Sub
End Class
你的题目中排列的是字符串，那吧Integer数组改成String数组就可以了，通过InputBox输入后可以用"xxx,xxx".Split(",")来分隔成String数组，结果要在TextBox显示，可以把这个代码中的Console.Write换成追加到全局变量，再显示到TextBox就行。自己改造一下吧。
