第一次机房收费系统 -- 模块篇

目的

为了方便以后直接调用，减少整体代码量

代码

Public UserName As String                                                       '定义全局变量 UserName
Public Declare Function SetParent Lib "user32" (ByVal hWndChild As Long, ByVal hWndNewParent As Long) As Long '使子窗体可以正常显示
Rem：系统启动时，首先执行，保证用户管理
Sub main()
    Dim fLogin As New UIFormLogin
    fLogin.Show vbModal                                                         '显示登录窗体
    If Not fLogin.OK Then
        'login failed so exit app
        End
    End If
    Unload fLogin
    'set fmainform = New frmMain 判断为是，进入系统，显示主窗体实例。
    MDImain.Show
End Sub

Rem：公共的数据操作函数，执行各种 SQL 语句。添加函数 ExecuteSQL(SQL 用来存放需要执行的 SQL 语句，MsgString 用来返回执行的提示信息)
Public Function ExecuteSQL(ByVal SQL As String, MsgString As String) As ADODB.Recordset '传递参数 SQL 传递查询语句，MsgString 传递查询信息
    Dim cnn As ADODB.Connection                                                 '自身以一个数据集对象的形式返回
    Dim rst As ADODB.Recordset                                                  '定义连接
    Dim sTokens() As String                                                     '定义字符串
    On Error GoTo ExecuteSQL_error                                              '异常处理
    sTokens = Split(SQL)                                                        '用 Split 函数产生一个包含各个子串的数组
    Set cnn = New ADODB.Connection                                              '创建连接
    cnn.Open ConnectString                                                      '打开连接
    If InStr("INSET,DELETE,UPDATE", UCase$(sTokens(0))) Then                    '判断字符串中是否含有指定内容
        cnn.Execute SQL                                                         '执行查询语句
        MsgString = sTokens(0) & "query successful"                             '返回查询信息
    Else
        Set rst = New ADODB.Recordset                                           '创建数据集对象
        rst.Open Trim$(SQL), cnn, adOpenKeyset, adLockOptimistic                '返回查询结果
        Set ExecuteSQL = rst                                                    '返回记录集对象
        MsgString = "查询到" & rst.RecordCount & "条记录"
    End If
ExecuteSQL_exit:
    Set rst = Nothing                                                           '清空记录集对象
    Set cnn = Nothing                                                           '中断连接
    Exit Function
ExecuteSQL_error:                                                               '错误类型判断
    MsgString = "查询错误：" & Err.Description
    Resume ExecuteSQL_exit
    Exit Function
End Function
Public Function ConnectString() As String
    ConnectString = "FileDSN=charge.dsn;UID=sa;PWD=123456"                      '返回一个数据库连接
End Function

Rem：检查各种文本框内容是否为空，定义 Testtxt 函数
Public Function Testtxt(txt As String) As Boolean
    If Trim(txt) = "" Then
        Testtxt = False
    Else
        Testtxt = True
    End If
End Function
Rem：限制特殊字符输入，定义 Number_KeyPress 函数
Public Sub Number_KeyPress(KeyAscii As Integer)
    Select Case KeyAscii
    Case 8
    Case Asc("0") To Asc("9")
    Case Else
        KeyAscii = 0
    End Select
End Sub
Rem：导出为 Excel 表
Public Sub Derive(FormName As Form, MSHFlexGridName As MSHFlexGrid)
    Dim TempExcel As Excel.Application                                          '用来创建一个工作薄
    Dim TempSheet As Excel.Worksheet                                            '用来创建一个工作表
    Dim intI As Integer                                                         '设置循环变量
    Dim intJ As Integer
    On Error GoTo Err_Proc
    Set TempExcel = New Excel.Application                                       '实例化为一个对象
    TempExcel.Application.Visible = True
    TempExcel.Workbooks.Add (1)

    Set TempSheet = TempExcel.ActiveWorkbook.ActiveSheet

    '对行和列进行循环，将数据填入到表中
    For intI = 0 To MSHFlexGridName.Rows - 1
        For intJ = 0 To MSHFlexGridName.Cols - 1
            TempSheet.Cells(intI + 1, intJ + 1) = MSHFlexGridName.TextMatrix(intI, intJ)
        Next intJ
    Next intI
Err_Proc:
    MsgBox "导出数据失败！", vbExclamation, "提示"
End Sub
Rem：限制特殊字符输入，定义 Number1_KeyPress 函数
Public Sub Number1_KeyPress(KeyAscii As Integer)
    Select Case KeyAscii
    Case 8
    Case Asc("0") To Asc("9")
    Case Else
        KeyAscii = 0
    End Select
End Sub

思考

在非计算机中，要学会经验复用，学会使用模板，让自己更高效。