modmain.bas

超市的管理系统

Attribute VB_Name = "ModMain"
'定义程序入口为frmlogin窗体
'定义符合登录条件的函数
Public Function Login(ByVal strUser As String, ByVal strPwd As String) As Boolean
    
    If strUser = "Admin" And strPwd = "123" Then
    
        Login = True
        
    Else
    
        Login = False
        
    End If
    
End Function
'定义输入数字时过滤条件的函数
Public Function IsNumber(ByVal str As String) As Boolean

    Dim i As Integer
    
    Dim intindex As Integer
    
    intindex = 0
    
    Dim length As Integer
    
    length = Len(str)
    
    IsNumber = True
    
    For i = 1 To length
    
        If Left(str, 1) >= "0" And Left(str, 1) <= "9" Or Left(str, 1) = "." Then
        
            If Left(str, 1) = "." Then
            
                intindex = intindex + 1
                
            End If
        
        Else
        
            IsNumber = False
            
            Exit Function
            
        End If
        
        str = Right(str, Len(str) - 1)   '此处的str动态变化！！
        
    Next i
    
    If intindex > 1 Then
    
        IsNumber = False
        
        Exit Function
        
    End If
    
End Function
'定义输入字符时过滤条件的函数
Public Function IsChar(ByVal str As String) As Boolean

    Dim i As Integer
    
    Dim length As Integer
    
    lengh = Len(str)
    
    IsChar = True
    
    For i = 1 To lengh
    
        If Left(str, 1) <> "'" And Left(str, 1) <> "[" And Left(str, 1) <> "]" _
            And Left(str, 1) <> "%" And Left(str, 1) <> "_" And Left(str, 1) <> " " Then
            
        Else
        
            IsChar = False
            
        End If
        
        str = Right(str, Len(str) - 1)
        
    Next i
    
        
End Function

Public Function IsEmpty(ByVal rs As ADODB.Recordset) As Boolean

    If rs.EOF = True Then
    
        MsgBox "数据表中无记录！", vbInformation + vbOKOnly, "无法查询！"
        
        IsEmpty = False
    Else
    
        IsEmpty = True
    
    
    End If

End Function