重载解析失败，因为对于这些参数，没有可访问的“新”是最具体的

Question

This is the code:

If ComboBox1.Text = "Total profil for all time" Then

        Dim TA As New CPDBTableAdapters.TotalProfilForAllTimeTableAdapter
        Dim TmpDS As New CPDB
        TA.Fill(TmpDS.TotalProfilForAllTime)


        'obriši prošli DS
        RV.LocalReport.DataSources.Clear()

        'dodaj novi DS
        Dim RDS As New Microsoft.Reporting.WinForms.ReportDataSource("", TmpDS.TotalProfilForAllTime)
        RV.LocalReport.DataSources.Add(RDS)
        RV.LocalReport.ReportEmbeddedResource = "change_password.report1.rdlc"
        RV.RefreshReport()


    End If

Problem is here:

Dim RDS As New Microsoft.Reporting.WinForms.ReportDataSource("", 
    TmpDS.TotalProfilForAllTime)

Error message: overload resolution failed because no accessible 'new'is most specific for these arguments.

Answer 1

Depending on the type of TmpDS.TotalProfilForAllTime, cast the second argument passed to the constructor:

Dim RDS As New Microsoft.Reporting.WinForms.ReportDataSource("", CType(TmpDS.TotalProfilForAllTime, DataTable))

or:

Dim RDS As New Microsoft.Reporting.WinForms.ReportDataSource("", CType(TmpDS.TotalProfilForAllTime, IEnumerable))

etc.

VB can't clearly pick the best constructor overload, so you have to provide some help to the compiler. See this link for the possible 2nd argument types expected. http://msdn.microsoft.com/en-us/library/microsoft.reporting.winforms.reportdatasource.reportdatasource(v=vs.100).aspx This is a common problem in VB code since VB is not very strict about interpreting object types - it allows more variation in allowing one object type being used in place of another (especially with Option Strict Off).