Constructor on type 'XYZ.Profiler' not found.

Question

_{Thursday, November 7, 2019 9:41 AM}

Hi,

I am using Dot net framework 2.0.... In am getting error in Bold and underline line...

The error message is

No parameterless constructor defined for this object. in c# or Constructor on type not found.

Please help me i am struggle since long.... Thanks in advance...

///Code Patch....

Assembly a = Assembly.LoadFrom(Application.StartupPath + "\XYS.exe");

Type mytypes = a.GetType("XYS.Profiler");
Object obj = Activator.CreateInstance(mytypes,new object[] {true});
mytypes.InvokeMember("CheckForExistingService", BindingFlags.Default | BindingFlags.InvokeMethod, null, obj, new object[] { sPortNumber });

All replies (11)

_{Thursday, November 7, 2019 9:53 AM}

Based on code you are trying to create instance of XYS.Profiler with constructor that has single boolean parameter and by error there is no such constructor. Are you sure there is matching constructor?

_{Thursday, November 7, 2019 10:13 AM}

Object obj = Activator.CreateInstance(mytypes);

This is the only line... I had added the extra parameter of Boolean to check ..

_{Thursday, November 7, 2019 10:39 AM}

Then there probably is not public parameterless constructor. You should check what constructors XYS.Profiler has and what parameters existing constructors require. Then you need to pass values to parameters of constructor that Activator will try to use to create instance.

You can read documentation for examples:

/en-us/dotnet/api/system.activator.createinstance?view=netframework-4.8

_{Thursday, November 7, 2019 11:16 AM}

Have you verified that XYZ.Profiler has public parametersless constructor?

_{Thursday, November 7, 2019 11:24 AM}

Public Class DepthProfiler

_{Thursday, November 7, 2019 12:25 PM}

That means it is declared as public class, but it does not mean it has public parameterless constructor that error refers to.

The declaration of public constructor is like

public class DepthProfiler
{
    /// <summary>
    /// This is the constructor Activator is looking for.
    /// </summary>
    public DepthProfiler()
    { }
}

There might also be implicit default constructor if class does not have any parameter constructors. If there is constructors with parameters, then parameterless constructor must be declared explicitly.

_{Thursday, November 7, 2019 12:56 PM}

Code of DepthProfiler

Imports Microsoft.SqlServer.Management.Trace

Imports Microsoft.SqlServer.Management.Common
Imports System.ServiceProcess
Imports System.Management

Public Class DepthProfiler
Dim t1 As New System.Threading.Thread(AddressOf DepthTracer)
Public Trace As TraceServer
Dim Processids As String = ""
Dim Ports As String = ""
Dim dt As DataTable
Public Function CheckForExistingService(ByVal iPorNumer As String) As Boolean
Diagnostics.EventLog.WriteEntry("SolutionGuru Distributor", iPorNumer)
Try
Shell("sc Create " & "SolutionGuru_REMOTE_WIN_SERVER_" & iPorNumer & " start= auto binPath= """ + Application.StartupPath & "\ & iPorNumer & "\SolutionGuru_REMOTE_WIN_SERVER.exe" + """ DisplayName= SolutionGuru_REMOTE_WIN_SERVER_" & iPorNumer & " ")
Shell("sc failure " & "SolutionGuru_REMOTE_WIN_SERVER_" & iPorNumer & " reset= 30 actions= restart/5000")
SaveSettings(iPorNumer)
Shell("sc Start " & "SolutionGuru_REMOTE_WIN_SERVER_" & iPorNumer & " ")
Return True
Catch ex As Exception
Diagnostics.EventLog.WriteEntry("SolutionGuru Distributor", ex.Message)
Return False
End Try
End Function
Public Function RestartServer(ByVal iPorNumer As String) As Boolean
fp_GetProcessIds(iPorNumer)
Try
Shell("sc Start " & "SolutionGuru_REMOTE_WIN_SERVER_" & iPorNumer & " ")
Return True
Catch ex As Exception
Diagnostics.EventLog.WriteEntry("SolutionGuru Distributor", ex.Message)
Return False
End Try
End Function
Public Sub fp_GetProcessIds(ByVal iPorNumer As String)
Try
For Each Prid As System.Diagnostics.Process In Process.GetProcesses
If Prid.ProcessName.ToUpper = "SolutionGuru_REMOTE_WIN_SERVER" Then
Dim iProcessId As Integer = Split(Mid(Prid.MainModule.FileName, InStrRev(Prid.MainModule.FileName, "\, -1, CompareMethod.Text) - 4), "\)(0)
If iProcessId = iPorNumer Then
Prid.Kill()
Exit For
End If
End If
Next
Catch ex As Exception

End Try
End Sub
Public Sub SaveSettings(ByVal iPorNumer As String)
Dim dsRCF As New DataSet
Dim dsPemoteAdmin As New DataSet

dsPemoteAdmin.ReadXml(Application.StartupPath & "\ & "SolutionGuru_REMOTE_DISTRIBUTOR.exe.config")
Dim str As String
str = Application.StartupPath
Diagnostics.EventLog.WriteEntry("SolutionGuru Distributor", str.ToString)
Try

dsRCF.ReadXml(Application.StartupPath & "\ & iPorNumer & "\SolutionGuru_REMOTE_WIN_SERVER.exe.config")
dsRCF.Tables("CHANNEL").Rows(0)("port") = iPorNumer
dsRCF.Tables("CHANNEL").Rows(0)("password") = dsPemoteAdmin.Tables("CHANNEL").Rows(0)("password")
dsRCF.Tables("CHANNEL").Rows(0)("username") = dsPemoteAdmin.Tables("CHANNEL").Rows(0)("username")

dsRCF.Tables("SETTING").Rows(0)("VALUE") = dsPemoteAdmin.Tables("SETTING").Rows(0)("VALUE")
dsRCF.Tables("SETTING").Rows(1)("VALUE") = dsPemoteAdmin.Tables("SETTING").Rows(1)("VALUE")
dsRCF.Tables("SETTING").Rows(2)("VALUE") = dsPemoteAdmin.Tables("SETTING").Rows(2)("VALUE")
dsRCF.Tables("SETTING").Rows(3)("VALUE") = dsPemoteAdmin.Tables("SETTING").Rows(3)("VALUE")
dsRCF.Tables("SETTING").Rows(4)("VALUE") = "tcp"
dsRCF.Tables("SETTING").Rows(5)("VALUE") = iPorNumer.Trim
dsRCF.Tables("SETTING").Rows(6)("VALUE") = dsPemoteAdmin.Tables("SETTING").Rows(6)("VALUE")
dsRCF.Tables("SETTING").Rows(7)("VALUE") = dsPemoteAdmin.Tables("SETTING").Rows(7)("VALUE")
dsRCF.Tables("SETTING").Rows(8)("VALUE") = dsPemoteAdmin.Tables("SETTING").Rows(8)("VALUE")
dsRCF.Tables("SETTING").Rows(9)("VALUE") = dsPemoteAdmin.Tables("SETTING").Rows(9)("VALUE")
dsRCF.Tables("SETTING").Rows(10)("VALUE") = dsPemoteAdmin.Tables("SETTING").Rows(10)("VALUE")
'dsRCF.Tables("SETTING").Rows(11)("VALUE") = ""
'dsRCF.Tables("SETTING").Rows(12)("VALUE") = ""
dsRCF.Tables("SETTING").Rows(13)("VALUE") = GetIPAddress()
'dsRCF.Tables("SETTING").Rows(13)("VALUE") = "192.168.3.18"
dsRCF.WriteXml(Application.StartupPath & "\ & iPorNumer & "\SolutionGuru_REMOTE_WIN_SERVER.exe.config")

Catch ex As Exception
Diagnostics.EventLog.WriteEntry("SolutionGuru Distributor", ex.Message)
End Try
End Sub
Shared Function GetIPAddress() As String
Dim oAddr As System.Net.IPAddress
Dim sAddr As String
With System.Net.Dns.GetHostByName(System.Net.Dns.GetHostName())
oAddr = New System.Net.IPAddress(.AddressList(0).Address)
sAddr = oAddr.ToString
End With
GetIPAddress = sAddr
End Function
Private Sub DepthTracer()
Try
While (Trace.Read())
If IsNothing(Trace("HostName")) = True Then Continue While
Dim v As String = Trace("HostName")
If Processids.Contains(Trace(4).ToString) = True And Trace("HostName").ToString.ToUpper.Contains(My.Computer.Name) = True Then
dt.Rows.Add()
dt.Rows(dt.Rows.Count - 1)(0) = Trace("StartTime")
dt.Rows(dt.Rows.Count - 1)(1) = Trace(0)
For Each str As String In Processids.Split(",")
If str.Contains(Trace(4).ToString) = True Then
dt.Rows(dt.Rows.Count - 1)(2) = str.Split("#")(1)
dt.Rows(dt.Rows.Count - 1)(3) = Trace("HostName").ToString 'str.Split("#")(1)
End If
Next
End If
End While
Catch ex As Exception
MsgBox(ex.InnerException.Message)
End Try

End Sub
Public Sub New(ByVal Servername As String, ByVal sUsername As String, ByVal sPassword As String, ByRef dtable As DataTable)
Try
GetProcessids()
Dim conninfo As ConnectionInfoBase = New SqlConnectionInfo
CType(conninfo, SqlConnectionInfo).ServerName = Servername '"192.168.3.247\QA"
CType(conninfo, SqlConnectionInfo).UserName = sUsername '"sa"
CType(conninfo, SqlConnectionInfo).Password = sPassword ' "quality"
CType(conninfo, SqlConnectionInfo).UseIntegratedSecurity = False
Trace = New TraceServer()
Trace.InitializeAsReader(conninfo, Application.StartupPath & "\Tracer.tdf")
t1.Start()
dt = dtable

Catch ex As Exception
MsgBox("Server Not Able to Trace For Server : " & Servername & " ")
End Try
End Sub

Private Sub GetProcessids()

Processids = ""
If Diagnostics.Process.GetProcessesByName("SolutionGuru_REMOTE_WIN_SERVER").Length > 0 Then
For Each Process1 As Process In Diagnostics.Process.GetProcessesByName("SolutionGuru_REMOTE_WIN_SERVER")
Ports = Split(Mid(Process1.MainModule.FileName, InStrRev(Process1.MainModule.FileName, "\, -1, CompareMethod.Text) - 4), "\)(0)
Processids = Processids & "," & Process1.Id & "#" & Ports
Next
Processids = Processids.Substring(1)
End If

End Sub
Protected Overrides Sub Finalize()
' If IsNothing(Trace) = False Then Trace.Stop()
MyBase.Finalize()
End Sub

End Class

_{Thursday, November 7, 2019 1:05 PM}

There is only this constructor

Public Sub New(ByVal Servername As String, ByVal sUsername As String, ByVal sPassword As String, ByRef dtable As DataTable)

So you need to pass value for those 4 parameters to activator to use that constructor to create instance. There might also be better way to create instance if you describe the problem you try to solve?

_{Friday, November 8, 2019 2:39 AM}

Hi Harish,

Thank you for posting here.

This is a question about constructors.

One thing to note is that if you don't add a constructor to a class, C# will create a no-argument constructor by default, but if you add a constructor with parameters, the default no-argument constructor will no longer be provided.

If you still need to use a no-argument construct at this time, please add it yourself.

At this point, VB.Net and C# are the same.

Hope this helpful.

Best Regards,

Timon

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_{Friday, November 8, 2019 9:55 AM}

Thanks both of you Timon Yang and MasaSam problem got solved...

By adding constructor with no parameter....

_{Monday, November 11, 2019 7:17 AM}