Question

我在Access 2010数据库的表单上显示了一个Subform / Subreport控件，我用它来显示表单和报表。我有一些事件处理程序，我需要知道报表当前是否加载到Subform / Subreport控件中，或者是否是一个已加载的Form。我已经尝试了以下所有方面无济于事。

以下任何一种情况

If IsEmpty(NavigationSubform.Form) Then '...
If IsNull(NavigationSubform.Form) Then '...
If IsOject(NavigationSubform.Form) Then '...
If NavigationSubform.Form Is Nothing Then '...
If NavigationSubform.Form Is Null Then '...
If Nz(NavigationSubform.Form) Then '...
If (Not NavigationSubform.Form) = -1 Then '... This is a trick I use to check for uninitialized arrays

结果

运行时错误'2467'：

您输入的表达式是指已关闭或不存在的对象。

我是否可以通过某种方式检查子窗体/子报表控件当前是否已加载表单或报表而不会故意导致错误？

Answer 1

我不相信有一种方法可以在没有错误捕获的情况下可靠地执行检查，因此您可能希望将代码包装在Public Function中并将其放入常规VBA模块中：

Public Function CheckSubformControlContents(ctl As SubForm) As String
Dim obj As Object, rtn As String
rtn = "None"
On Error Resume Next
Set obj = ctl.Form
If Err.Number = 0 Then
    rtn = "Form"
Else
    On Error Resume Next
    Set obj = ctl.Report
    If Err.Number = 0 Then
        rtn = "Report"
    End If
End If
Set obj = Nothing
On Error GoTo 0
CheckSubformControlContents = rtn
End Function

然后，您的表单代码只需调用CheckSubformControlContents(Me.NavigationSubform)。

Answer 2

以下是两个在Access 2013中用于确定名称是报表还是表单的函数。确定后，可以使用AllForms或AllReports的IsLoaded函数。请注意，dbs是一个对象，rpt或frm是AccessObjects而不是表单或报告

Public Function IsForm(FormName As String) As Boolean
    Dim dbs As Object
    Dim frm As AccessObject
    Set dbs = Application.CurrentProject
    IsForm = False
    For Each frm In Application.CurrentProject.AllForms
        If frm.Name = FormName Then
            IsForm = True
            Exit For
        End If
    Next frm
    Set frm = Nothing
    Set dbs = Nothing
End Function
Public Function IsReport(ReportName As String) As Boolean
    Dim dbs As Object
    Dim rpt As AccessObject
    Set dbs = Application.CurrentProject
    IsReport = False
    For Each rpt In Application.CurrentProject.AllReports
        If rpt.Name = ReportName Then
            IsReport = True
            Exit For
        End If
    Next rpt
    Set rpt = Nothing
    Set dbs = Nothing
End Function

这是一个使用上述功能的程序：

Public Sub EnumerateTaggedControls（ReportName As String，MyTag As String）昏暗的dbs作为对象 Dim rpt As Report Dim frm As Form Dim col As Controls 昏暗的ctl作为控制 Dim left As Integer Dim top As Integer 昏暗宽度为整数昏暗高度为整数 Dim标签为String Dim i As Integer Const format1 As String =“0000”

Set dbs = Application.CurrentProject
If IsForm(ReportName) Then
    If dbs.AllForms(ReportName).IsLoaded Then
        DoCmd.OpenForm ReportName, acViewDesign
        Set frm = Forms(ReportName)
        Set col = frm.Controls
    End If
Else
    If dbs.AllReports(ReportName).IsLoaded Then
        DoCmd.OpenReport ReportName, acViewDesign
        Set rpt = Reports(ReportName)
        Set col = rpt.Controls
    Else
        Debug.Print ReportName & " is not a loaded form or report."
        Exit Sub
    End If
End If
Set dbs = Nothing
Debug.Print Tab(53); "Left   Top    Width  Height"
For Each ctl In col
    With ctl
    left = .Properties("Left")
    top = .Properties("Top")
    width = .Properties("Width")
    height = .Properties("Height")
    tag = Nz(.Properties("Tag"), vbNullString)
    If MyTag = "" Then
        i = 1
    Else
        i = InStr(1, tag, MyTag)
    End If
    If i > 0 Then
        Debug.Print .Name & ">"; Tab(33); tag; Tab(53); Format(left, format1) &         Format(top, format1) & Format(width, format1) & Format(height, format1)
    End If
    End With
Next ctl
Debug.Print "====================================================="
Set ctl = Nothing
Set rpt = Nothing
Set col = Nothing
Set frm = Nothing

End Sub

我希望这符合您的要求。

确定Subform / Subreport是否在MS Access中加载了表单或报表

2 个答案: