SqlClientPermission Failed When Accessing Database By Loading Assembly From Web?
Apr 25, 2012
I have 1 exe and 1 dll. The dll (ClassLibrary1) file is located in the root of a website. In the dll I have a UserControl that populates with data its controls, from a database that is on a website too. The end user gets the exe file. This exe loads the dll and displays the UserControl1 on the form. This is how i load the control from inside the dll (located on the web site), on my form (exe file).
Private _dll As String = "http://www.site.com/ClassLibrary1.dll"
Private _class As String = "ClassLibrary1.UserControl1"
Private WithEvents cont As UserControl
[code]....
The error is "Request for the permission of type 'System.Data.SqlClient.SqlClientPermission, System.Data, Version=2.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089' failed."Note that if i dont load the usercontrol from the web and instead have it locally, there is no problem. The data are fetched from the database (db is on the web) with no problem.The problem seems to be that the loaded assembly from the web (the usercontrol1 inside the dll) has no permission to access anything. I am not trying to access stuff from the user's pc (like file IO), but access a database located on a web server.
sAssemblyName is the one I loaded using LoadFrom() actually. After it said it cannot find the assembly, I used AssemblyResolve event which solved my problem :Subscribing AssemblyResolve event :
Private Shared Function MyResolveEventHandler(ByVal sender As Object, _ ByVal args As ResolveEventArgs) As Assembly Return Assembly.LoadFrom("C:\PSIOBJ\" + args.Name + ".dll") End Function
And I thought maybe the error occurs because it cannot find a dependent assembly defined in assembly manifest file I loaded using LoadFrom() already but when I checked the args.Name, I saw it was trying to load same assembly and after that it worked without any problem. So basically a type in the loaded assembly cannot be found before the event adding change.
My old code was using AppDomain.CurrentDomain.Load() and Assembly.Load() methods and they were working fine without the AssemblyResolve event. I was able to reach types in dynamically loaded Assembly from every where within the same AppDomain.
LoadFrom() can find dependencies automatically within the same requested assembly path and that couldn't be problem as everything this dll needs was there. So at first it looked like a AppDomain problem to me as it looks like it seems it can reach assemblies from Load context instead of LoadFrom context and I am now using LoadFrom context.But now it seems I should pass oAssembly instance evertwhere to use any type from the loaded assembly?Doesn't it load the assembly where I can reach it everywhere (same AppDomain) using simple Type.GetType(...) method?
I've been having an error with my Visual Studio 2008 with .net framework 3.5 Sp1. I am creating a project, and it would run properly until after a while when I try debugging the project I would get a error message that says: "Error while trying to run project: Could not load file or assembly 'Name_of_Project' or one of its dependencies. The module was expected to contain an assembly manifest."
Also the .exe file that it creates in the bindebug folder gives and error that says: "The application failed to initialize properly (0xc000007b). Click OK to terminate the application." These errors after a format of the machine would disappear for awhile but not indefinitely.
I'm using an interop COM assembly in my 1.1 VB.NET code, and when I try to set a property of a class, I get an InvalidCastException with the message "QueryInterface for Interface ¦ failed."
I am getting a "Method not found: 'Boolean MyCompany.LibraryAssembly.SomeFunction (System.String)'" Exception/error when running a VB.NET console application. The method is part of an external assembly and it is definitely in the assembly. The error only occurs at runtime when I go to enter the function that calls the method. I have the assembly referenced by my project and I am not copying it locally. Intellisense shows no errors, and neither does the compiler. I am loading the assembly statically not dynamically. I reference the from a local folder (not the GAC) although the same version is also available from the GAC.
i am writing a simple games client using an XNA 2.0 engine to play games. The games are written in dll files and the client uses the assembly.loadfrom method to read and execute the games accordingly...Now this all works fine on my computer and my laptop. However when i give it to my friend he gets this error and the dll doesnt load - "Unable to load one or more of the requested types. Retrieve the loader exceptions property for more information"
I now have a need to dynamically load a dll into my application and I've found the reflection/assembly information and it's fairly easy to implement so I thought I was on my way. However, I quickly found out that I'm only able to use 'shared' methods. What I was originally thinking was I could have one shared method 'library.beginprocess' and then that would make all the necessary calls to the other methods, but this doesn't work unless all the other methods and class level objects are also shared.
I feel like I'm missing something or somethings just going right over my head. I've looked at many, many sites and examples, but I've only run across examples that expose 1 method,[URL]..which explain how to implement a plugin architechture, which I have not tried yet, but maybe would allow me to keep my class structure the same without having to make everything shared?
I'm populating a DataGridView from a file with the following
Dim fnum As Short = FreeFile() Dim inputLine As String Dim i As Short = 0 Dim strAuditDate As String Dim strAuditTime As String Dim msg As String
[Code]...
When I do this, the MessageBox.Show shows the contents of a row, which is tab delimited. How do I get the data that I read to display in columns of the Gridview?
In the game I'm making I have a background worker thread simulating the game and constantly outputting data to a file.I want to be able to access that file while simulation is going on. I understand that you can't access the same file simultaneously in two threads so I don't mind having the program (say on a button click) wait until the simulation isn't using the file.I can't seem to do that though! Whenever I either save or load the file I have a bolAccessingFiles variable which I check to make sure things don't happen simultaneously. I change the value to True just before opening any files and False just after closing any files.
This doesn't seem to work though. It seems as though the computer will still be using the file in some way even though the code has kept going. I need that when I next access the file I have a stronger way of checking if the file is already in use, and if so make it wait."The process cannot access the file 'C:UsersDavidDocumentsVisual Studio 2010ProjectsGameGameinx86Debugoutput.txt' because it is being used by another process."
The LoadFrom() method takes the assembly filepath as its argument, but the filepath is merely providing the assembly identity information as a clue to the CLR. The LoadFrom() method still internally calls Load() with that identity information. So it is quite possible that LoadFrom(filepath) will load a totally different assembly from the one specified by the filepath. But the tame LoadFile() method will just load the assembly we specified.
I am wondering why do we need the LoadFrom() method? It adds nothing but confusion and pitfall. Is there any scenario that only LoadFrom() is applicable?
I'm using Visual Basic Express 2010 and SQL Express 2008 in Windows XP. At first I couldn't add a datasource (the .mdf file for the database) because of a "Operating system error 32" which I seemed to have resolved by giving myself full permissions for .mdf file (by right clicking on the file and going into properties and then Security) and restarting the SQL SERVER (SQLEXPRESS) service. The dataset for the database is in my solution explorer but when I right click on a table adapter to add a query and attempt to open up the query builder, I get the error in the title above.
Assume a .NET class library code that, for example, writes to the Windows registry. Then this code has problem to run over internet, because default Internet policy does not give access to write to the registry.By adding a RequestMinimum statement in the assembly we can specify that the code requires permission to write to write to the registry. This will not alter the fact that the code does not have the permission, but will stop the assembly from loading; the runtime will throw a System.Security.Policy.PolicyException and identify the permission that is required.Do you now any other examples of using evidence, security policy and permissions (the key elements of code-access security) to prevent an assembly from loading on a web server?
I'm using Visual Basic Express 2010 and SQL Express 2008 in Windows XP.I created a database on my local PC HDD. At first I couldn't add a datasource (the .mdf file for the database) because of a "Operating system error 32" which I seemed to have resolved by giving myself full permissions for .mdf file (by right clicking on the file and going into properties and then Security) and restarting the SQL SERVER (SQLEXPRESS) service.The dataset for the database is in my solution explorer but when I right click on a table adapter to add a query and attempt to open up the query builder, I get the error in the title above.
script on various Operating Systems like Windows2000Professional,Windows2000Server, WindowsXPProfessional. Having exactly the sameconfiguration, on some machines it works absolutely fine and on some itgives following error.
Error : WSDLReader:Loading of the WSDL file failed. HRESULT=0x80040154: Class not registered. Code : 80020009
I have an application that runs inside my company network in several computers, the application access a SQL Server in another place in the network. I coded the application and everything in my machine worked fine but when put the release version inside the users machines i get an error:Application attempted to perform an operation not allowed by the security policy. To grant this application the required permission, contact your system administrator, or use the Microsoft.NET Framework Configuration tool. Request for the permission of type
I have developed a website that allows users to upload office documents then uses the office object model to convert the document to an HTML file that it then displays in an iFrame. I have, of course, included references to Office.interop.word, and the site works fine on my development machine. When I uploaded it to my production server the site functions fine until I try to upload a document. I initially got a similar error that said "COM object not registered". I realized that Word wasn't installed on my production server. So I installed word and now when the server tries to access the word object model I receive the following error:
Retrieving the COM class factory for component with CLSID {000209FF-0000-0000-C000-000000000046} failed due to the following error: 80070005 Access is denied. (Exception from HRESULT: 0x80070005 (E_ACCESSDENIED))
I searched the registry for the corresponding CLSID and found a corresponding folder. I added full control to the IUSR_ account and due to the persistence of the error I eventually added full control to "everyone" and ensured these permissions inherited down to the rest of the folder. I then added full control to IUSR_ and again eventually added full control to "everyone" to my microsoft office folder.
I don't know what other permissions to grant and where in order to make this "Access is denied" error go away. I must be granting them in the wrong place, because as far as I know I can't be any more permissive than "Everyone" "Full Control".
I have created an application using vb.net 2008 and for reports Crystal Reports Basic for Visual Studio 2008 but the problem is, when I run the application in another machine away from developing box, I get the Load report failed notice. I don't have any idea on how I should approach this issue. I tried installing the CRRedist2008_x86 and CRRedist2005_x86 but still the problem won't go away.
I have a report made in Crystal Reports XI. The report is generated and exported to PDF in visual basic script using COM interface. Generally everything is running smoothly, but in one case generation breaks with error: Failed to retrieve data from the database. Details: [Database Vendor Code 9421]
Database used is MSSQL 2005 connected over ODBC to CR XI. When I am opening report with exactly the same parameters in Designer, everything works fine.It looks like it is data related, but it is hard to trace since the whole report is pretty sophisticated. Anyway I spent half a day on crawling over Dr. Google and it seems that he has no clue what might be an issue.
I am working on a windows application in vb.net 2005 and it needs to connect to the SQL Server database. In this example I testing if the connection is able to open properly:
[Code]...
Is it something dealing with the permissions set with the database server or something? I am new at .NET programming and I have been spinning my wheels on this for the past couple of days and I am at a loss. From what I research, this error should only occur if I was creating a web program, but I am not. It is a windows application.
O/S WIndows 7 SQL Server : SQL Express 2008 R2 VB 2010 Express
SQL Server is located on the workstation so the code and the DB are on the same PC
Created a DB connection using the wizard. Tried this with Windows authentication and SQL authentication using sa
Created a Dataset and dragged the grid onto the form1.vb.
In SQL Sertver Management Studio I can update update tables using the same credentials as in the VB connection string
WHen I try to update a record in the VB Dataset it returns the error cannot update database because it is read-only
I have checked the files and folder attributes in SQL Data folder. Nothing is set to read only
I have checked SQL Server Database > Properties > Option > State > Databse Read only = false
I don't what I'm doing wrong here but I cannot get VB to update data via the dataset.
Inotice in SQL Server that the DBname now includes the full path "C:PROGRAM FILESMICROSOFT SQL SERVERMSSQL10_50.SQLEXPRESSMSSQLDATAPAYABLES.MDF" and not just the DB name. Is this becuase VB Express requires you to point to the physical DB file?
I created a SQL DB named MainDB.mdf and a small VB 2010 application with some forms and datasets.Everything was working OK until i got a new computer and re-installed Visual Studio 2010 and SQL server 2010 on it. I copied my DB from the old to the new computer and also copied by VB 2010 project to it. I used Windows Authentication to connect to the DB in the old computer and also in the new one, i am using different Windows user account names though.
I was able to connect to the DB in the new computer in the Server Explorer section, i created a new connection string to the DB and i can seed there is data in the tables. When i run my VB 2010 application created in the old computer get error:
"Cannot open database "MainDB" requested by the login. The login failed. Login failed for user 'D630Admin'."
I need to get rid of that error and be able to add/mod/del data from my DB using my VB application as i used to.
I am developing an application that is using a Jet database (Access 2007). The database is local to the project (e.g., on the same drive and in the project directory). Any time I attempt to access the database (to create another DataSet, etc., via designer, etc.), I get the ubiquitous "Failed to open a connection to the database" with: No error message available, result code: E_UNEXPECTED(0x8000FFFF). Opening the Database Explorer and attempting to attach to the database results in the above as well. There are no apparent locks on the file, etc., and I'm the sole developer for this.
I am currently working on a project for school. I have the project all laid out in my mind and everything but there is one thing that stops me. I can not access the data from the database itself ...
(detailed info)
I am using an AMD Athlon x64 bit processor with a windows vista 64 bit operating system. I am writing the program on visual basic 2008 express edition. When I open up the visual basic 2008 express edition and create a new project the first thing I do is go to the view menu and activate my database explorer. I connect to the database in question through the database explorer. The database I am connecting to is an access 2007 database (ive opened up the access 2007 files and they do open and display information properly, in otherwords, they do work) I then put in a listbox and use the following lines of code in a form load event to both A) create the datatable and B) automatically fill the listbox with the database info.
Dim dt As New DataTable() Dim connStr As String = "Provider=Microsoft.Jet.OLEDB.4.0;" & _ "Data Source=MEGACITIES.MDB"
[Code]....
When I test the program the listbox does not fill up with any information from the MEGACITIES access 2007 database. Ive tried connecting to the database by establishing a connection through the datasources window. Ive tried establishing a connection to the database through both the database explorer and data sources window. No matter what I try I can not get that information accessed.
Im almost confident that this has to do with my processor being 64 bit.
i started using VB 2008 recently (with perl background, its a big leap) and having a problem with database.i am trying to access a database that is attached to a different form. i managed to get my code to work if i was writing on the same form.example of code that will work just fine Private Sub Button2_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button2.Click
Public con As New SqlConnection("Data Source=.\SQLEXPRESS;AttachDbFilename=C:\Tramsco\Tramsco\payroll.mdf;Integrated Security=True;User Instance=True;MultipleActiveResultSets=True")
as my connection string and when i run the .exe from the other computer to access the database on the host, it gives me this error:
An attempt to attach an auto-named database for file C:\Tramsco\Tramsco payroll.mdf failed. A database with the same name exists, or specified file cannot be Opened, or it is located on UNC share.
but when i use the computer where the program is, i can run it with no problem.
