adodc一定要与数据显示控件一起用吗

在form里添加了一个adodc控件，指向数据库里的表，但adodc没有与像datagrid这样的控件一起使用，就是adodc指向的数据不显示出来。程序如下：               If UserInformation.RecordSet.EOF = False Or UserInformation.RecordSet.BOF = False Then

                UserInformation.RecordSet.MoveFirst

             Else

                CommunicationOrder = Over

             End If但是有错误提示"run-time'91':object variable or with block variable not set"

     出现这种错误，是因为adodc的属性没有设置好呢，还是应为没有与其他控件一起使用的原因呢？

解决方案 »

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不用用ado就可以,最好不要用控件.你这个代码写得真乱,完全不明UserInformation是你的ADODC控件名字? 晕命名规范学习一西
CommunicationOrder = Over //这是什么?另外错误代码出现在那一句?
出错一句
If UserInformation.RecordSet.EOF = False Or UserInformation.RecordSet.BOF = False Then CommunicationOrder是一个字符串变量，over是一个定义了出值的常量我现在想从数据表里取数据发送出去，用adodc连接数据表，但提示上面一句有错误，我想错误可能出在ado上，我加了个datagrid就没错了，是不是一定要加datagrid给ado呢？
Private Decode(1 To 64) As String
Private BufferCount As Integer
Private OperationBuffer As String
Private ReadOperation As String
Private ReturnOperationCode As String
Private OfflinePermit As String
Private Over As String
Public ReceiveBuffer As StringPrivate Sub Form_Load()CommunicationOrder = ""ReturnOperationCode = 1SendOperation = 2
ReadOperation = 3UserQuit = 4
SendOfflinePermit = 5              Over = "10"                                   '循环连接编码Case条件变量    '设置串口属性, 打开串口
    'Module1.BuadRate = 19200
    MSComm1.CommPort = 1                        '设置或返回端口号，值为1到16的整数，PC通常可以有16个串口
    MSComm1.InBufferSize = 1024                 '设置接收缓冲区的大小
    MSComm1.Settings = "115200,n,8,1"           '设置并返回通讯参数，值为字符串String行
    'MSComm1.Settings = BaudRate & ",n,8,1"
    MSComm1.InputLen = 0                        '设置或返回，从接收缓冲区读取的字符数，0时（默认），读取缓冲区全部字符
    MSComm1.RThreshold = 1                      '接收区的“门阀值”，0时（默认），不产生OnComm事件；1时，接收缓冲区每接收到一个字符，都会产生OnComm事件
    MSComm1.SThreshold = 1                      '发送区的“门阀值”，0时（默认），不产生OnComm事件；1时，发送缓冲区每接收到一个字符，都会产生OnComm事件
    MSComm1.InBufferCount = 0
    'MSComm1.PortOpen = True                     '通讯时，必须打开串口，应用程序完成时，MSComm控件自动关闭串口
    MSComm1.InputMode = comInputModeText        '以文本方式取回传入的数据，既comInputModeText = 0
    'Shape3.BackColor = &HEF00&    '建立本地数据库的连接，显示记录集
    LinkReceiveOperationAdodc.ConnectionString = Module1.ConnectString
    LinkReceiveOperationAdodc.CommandType = adCmdText
    LinkReceiveOperationAdodc.RecordSource = "select * from ReceiveOperationList where Status = 1 "
    LinkReceiveOperationAdodc.Mode = adModeReadWrite

'强制打开串口
    If MSComm1.PortOpen = False Then
       MSComm1.PortOpen = True
    End If

    '设置接收计时器Timer2的参数，先关闭计时器，在发送时，再启动计时器扫描
    ScanTimer.Interval = 50
    ScanTimer.Enabled = False

End Sub
Private Sub ScanTimer_Timer()ReceiveBuffer = MSComm1.Input
Sleep (10)CommunicationOrder = Mid(ReceiveBuffer, 3, 1)Select Case CommunicationOrder:    Case ReturnOperationCode
        If LinkFinishOperationAdodc.RecordSet.EOF = False Or LinkFinishOperationAdodc.RecordSet.BOF = False Then

             LinkFinishOperationAdodc.RecordSet.MoveFirst

        Else
             Exit Sub
        End If

    Case ReadOperation
        If LinkReceiveOperationAdodc.RecordSet.EOF = False Or LinkReceiveOperationAdodc.RecordSet.BOF = False Then

             LinkReceiveOperationAdodc.RecordSet.MoveLast

        Else

             LinkReceiveOperationAdodc.RecordSet.AddNew

             End If

        Call ReceiveDecode

    Case UserQuit
            If UserInformation.RecordSet.EOF = False Or UserInformation.RecordSet.BOF = False Then
                Call OfflineOperation
            Else
             Exit Sub
            End If
     Case Over
            CommunicationOrder = ""
    End Select
    DoEvents
    CommunicationOrder = ""
    ReceiveBuffer = ""
End SubPrivate Sub StartCircleCommand_Click()
    ScanTimer.Enabled = True
End Sub
Private Sub ReceiveDecode()
'显示接收表当前的记录集，接收状态=1的记录'从ReceiveBuffer拆字符，然后放入对应的变量和数组    CodeLength = Left(ReceiveBuffer, 1)
    TerminalID = Mid(ReceiveBuffer, 2, 1)    CommunicationCode = Mid(ReceiveBuffer, 3, 1)
    LocalStationID = Mid(ReceiveBuffer, 4, 1)

    ContainerIDArray(0) = Mid(ReceiveBuffer, 5, 1)
    ContainerIDArray(1) = Mid(ReceiveBuffer, 6, 1)
    ContainerIDArray(2) = Mid(ReceiveBuffer, 7, 1)
    ContainerIDArray(3) = Mid(ReceiveBuffer, 8, 1)
    ContainerIDArray(4) = Mid(ReceiveBuffer, 9, 1)
    ContainerIDArray(5) = Mid(ReceiveBuffer, 10, 1)
    ContainerIDArray(6) = Mid(ReceiveBuffer, 11, 1)
    ContainerIDArray(7) = Mid(ReceiveBuffer, 12, 1)
    ContainerIDArray(8) = Mid(ReceiveBuffer, 13, 1)
    ContainerIDArray(9) = Mid(ReceiveBuffer, 14, 1)
    ContainerIDArray(10) = Mid(ReceiveBuffer, 15, 1)

    SourceAddressArray(0) = Mid(ReceiveBuffer, 16, 1)
    SourceAddressArray(1) = Mid(ReceiveBuffer, 17, 1)
    SourceAddressArray(2) = Mid(ReceiveBuffer, 18, 1)
    SourceAddressArray(3) = Mid(ReceiveBuffer, 19, 1)
    SourceAddressArray(4) = Mid(ReceiveBuffer, 20, 1)
    SourceAddressArray(5) = Mid(ReceiveBuffer, 21, 1)
    SourceAddressArray(6) = Mid(ReceiveBuffer, 22, 1)
    SourceAddressArray(7) = Mid(ReceiveBuffer, 23, 1)

    TargetAddressArray(0) = Mid(ReceiveBuffer, 24, 1)
    TargetAddressArray(1) = Mid(ReceiveBuffer, 25, 1)
    TargetAddressArray(2) = Mid(ReceiveBuffer, 26, 1)
    TargetAddressArray(3) = Mid(ReceiveBuffer, 27, 1)
    TargetAddressArray(4) = Mid(ReceiveBuffer, 28, 1)
    TargetAddressArray(5) = Mid(ReceiveBuffer, 29, 1)
    TargetAddressArray(6) = Mid(ReceiveBuffer, 30, 1)
    TargetAddressArray(7) = Mid(ReceiveBuffer, 31, 1)

    TruckNumberArray(0) = Mid(ReceiveBuffer, 32, 1)
    TruckNumberArray(1) = Mid(ReceiveBuffer, 33, 1)
    TruckNumberArray(2) = Mid(ReceiveBuffer, 34, 1)
    TruckNumberArray(3) = Mid(ReceiveBuffer, 35, 1)
    TruckNumberArray(4) = Mid(ReceiveBuffer, 36, 1)
    TruckNumberArray(5) = Mid(ReceiveBuffer, 37, 1)
    TruckNumberArray(6) = Mid(ReceiveBuffer, 38, 1)
    TruckNumberArray(7) = Mid(ReceiveBuffer, 39, 1)

    ContainerWeight = Mid(ReceiveBuffer, 40, 1)
    ContainerSize = Mid(ReceiveBuffer, 41, 1)
'将数组转成字符，再合并成字符串

    ContainerID = ContainerIDArray(0) & ContainerIDArray(1) & ContainerIDArray(2) & ContainerIDArray(3) & ContainerIDArray(4) & ContainerIDArray(5) & ContainerIDArray(6) & ContainerIDArray(7) & ContainerIDArray(8) & ContainerIDArray(9) & ContainerIDArray(10)
    SourceAddress = SourceAddressArray(0) & SourceAddressArray(1) & SourceAddressArray(2) & SourceAddressArray(3) & SourceAddressArray(4) & SourceAddressArray(5) & SourceAddressArray(6) & SourceAddressArray(7)
    TargetAddress = TargetAddressArray(0) & TargetAddressArray(1) & TargetAddressArray(2) & TargetAddressArray(3) & TargetAddressArray(4) & TargetAddressArray(5) & TargetAddressArray(6) & TargetAddressArray(7)
    TruckNumber = TruckNumberArray(0) & TruckNumberArray(1) & TruckNumberArray(2) & TruckNumberArray(3) & TruckNumberArray(4) & TruckNumberArray(5) & TruckNumberArray(6) & TruckNumberArray(7)
    '对记录集进行填加新的记录
    '将合并的字符串，分别放入记录集所对应的字段，同时补加日期和时间值
    'LinkReceiveOperationAdodc.RecordSet.AddNew
    LinkReceiveOperationAdodc.RecordSet.Fields("CodeLength") = CodeLength
    LinkReceiveOperationAdodc.RecordSet.Fields("TerminalID") = TerminalID
    LinkReceiveOperationAdodc.RecordSet.Fields("CommunicationCode") = CommunicationCode
    LinkReceiveOperationAdodc.RecordSet.Fields("LocalStationID") = LocalStationID

    LinkReceiveOperationAdodc.RecordSet.Fields("ContainerID") = ContainerID
    LinkReceiveOperationAdodc.RecordSet.Fields("SourceAddress") = SourceAddress
    LinkReceiveOperationAdodc.RecordSet.Fields("TargetAddress") = TargetAddress
    LinkReceiveOperationAdodc.RecordSet.Fields("TruckNumber") = TruckNumber
    LinkReceiveOperationAdodc.RecordSet.Fields("ContainerWeight") = ContainerWeight
    LinkReceiveOperationAdodc.RecordSet.Fields("ContainerSize") = ContainerSize
    LinkReceiveOperationAdodc.RecordSet.Fields("ReceiveDate") = Date
    LinkReceiveOperationAdodc.RecordSet.Fields("ReceiveTime") = Time()
    LinkReceiveOperationAdodc.RecordSet.Fields("Status") = "1"
    LinkReceiveOperationAdodc.RecordSet.AddNew
    End SubPrivate Sub ReturnOperation()'在完成操作的记录集中，定位第一条记录，开始编码，组成字符串，送到串口发送
LinkFinishOperationAdodc.RecordSet.MoveNext'将合并的字符串，分别放入记录集所对应的字段，同时补加日期和时间值

    CodeLength = LinkFinishOperationAdodc.RecordSet.Fields("CodeLength")
    TerminalID = LinkFinishOperationAdodc.RecordSet.Fields("TerminalID")
    CommunicationCode = 3 ' LinkFinishOperationAdodc.RecordSet.Fields("CommunicationCode")
    LocalStationID = LinkFinishOperationAdodc.RecordSet.Fields("LocalStationID")

    ContainerID = LinkFinishOperationAdodc.RecordSet.Fields("ContainerID")
    SourceAddress = LinkFinishOperationAdodc.RecordSet.Fields("SourceAddress")
    TargetAddress = LinkFinishOperationAdodc.RecordSet.Fields("TargetAddress")
    TruckNumber = LinkFinishOperationAdodc.RecordSet.Fields("TruckNumber")
    ContainerWeight = LinkFinishOperationAdodc.RecordSet.Fields("ContainerWeight")
    ContainerSize = LinkFinishOperationAdodc.RecordSet.Fields("ContainerSize")

    LinkFinishOperationAdodc.RecordSet.Fields("Status") = "0"

    '合并成串口字符串
    OperationBuffer = CodeLength & LocalStationID & CommunicationCode & TerminalID & ContainerID & SourceAddress & TargetAddress & TruckNumber & ContainerWeight & ContainerSize & "1"

    '调用发送字符串子程序
       MSComm1.Output = OperationBuffer
End SubPrivate Sub OfflineOperation()
Dim UserID As String
Dim UserPassword As String
If UserInformation.RecordSet.Fields("UserID") = "" Or UserInformation.RecordSet.Fields("UserPassword") = "" Then        Exit Sub
    Else
    UserID = UserInformation.RecordSet.Fields("UserID")
    UserPassword = UserInformation.RecordSet.Fields("UserPassword")End If      OperationBuffer = Chr(Len("e5" & UserID & UserPassword)) & "e5" & UserID & UserPassword

    '调用发送字符串子程序
       MSComm1.Output = OperationBuffer
End Sub
整理了一下，但是代码还是有点乱，主要是边调，边改。还有个问题，在Select Case CommunicationOrder:语句中，CommunicationOrder是用来存从串口接受的数据的第三个字节数据的，之后对其判断。但是在串口没有接受数据时，却执行了执行下面这段，
    Case UserQuit
            If UserInformation.RecordSet.EOF = False Or UserInformation.RecordSet.BOF = False Then
                Call OfflineOperation
            Else
             Exit Sub
            End If
     Case Over
            CommunicationOrder = ""
    End Select
此时我加了datagrid，上面的错误"run-time'91':object variable or with block variable not set" 没有了。但是CommunicationOrder 为“”空啊，怎么执行到case UserQuit  就成立了呢？
在开始要加一句：adodc1.refresh
你的代码比较长，没有时间仔细看，你可以在form_load中在使用adodc1之前加上adodc1.refresh
在使用前加adodc1.refresh，问题解决。但是另一个问题
在Select Case CommunicationOrder:语句中，CommunicationOrder是用来存从串口接受的数据的第三个字节数据的，之后对其判断。但是在串口没有接受数据时，却执行了执行下面这段，
    Case UserQuit
            If UserInformation.RecordSet.EOF = False Or UserInformation.RecordSet.BOF = False Then
                Call OfflineOperation
            Else
            Exit Sub
            End If
    Case Over
            CommunicationOrder = ""
    End Select
此时我加了datagrid，上面的错误"run-time'91':object variable or with block variable not set" 没有了。但是CommunicationOrder 为“”空啊，怎么执行到case UserQuit  就成立了呢？
是不是因为UserQuit 没有定义的原因呢？我在程序最顶端加了Private UserQuit As String之后，case语句就正常了，不会在没有接受到“UserQuit”的情况下运行Case UserQuit了。   是不是没有定义UserQuit引起了select case出错呢？
还有If UserInformation.RecordSet.Fields("UserID") = "" Or UserInformation.RecordSet.Fields ("UserPassword") = "" 这句总是提示“invalied use of null",为什么呢？
1.是没有定义UserQuit引起了select case出错
2.UserInformation.RecordSet.Fields("UserID")或者 UserInformation.RecordSet.Fields"UserPassword")为NULL，应该先用IsNull(UserInformation.RecordSet.Fields("UserID") )和IsNull(UserInformation.RecordSet.Fields("UserPassword") )进行判断。不过，建议这些字段在数据库中就设为不允许为NULL,一般来说，更为合理些。