C# - Update Client On Any Changes Occurred On Server?
Dec 28, 2010
i need to update client on any changes occurred on server.for that i found 2 approach.
1. using ajax which is also known as reverse ajax for this purpose.
2. using COMET.
but i don't know exact difference in both.
my site contains news content and i want that news to be automatically updates when new news is entered by my CMS application. i have got hundreds of concurrent users on my web application.
NOTE: i am using .net framework 2.0 but if its not possible in 2.0 then can also move to 3.5
I have two list boxes and I am using javascript to interchange the items. My problem is, When I press submit button before any changes in the listboxes, it would fire the eventhandler. But when I made any change in these listboxes, a postback happened and the controls became invisible. (There is an html tag and an empty body tag in the source). I know listbox cannot preserve the client side changes to the server. But I could not identify the problem.
I want to run code at the server(sql update) on a client button click, but i dont want a postback (more specifically, page flicker or loss of scrolling position).
My scenario is that when a user clicks a link to download a file, a large file will be downloaded. But many files are zipped and to become a requested large file, files are needed to be unzipped at the server side and download it. Meanwhile unzipping the files, I wanna show to the user how many percent of files have been unzipped.
So, I save the current condition of % into the session () and it has been updated accordingly and in the other page session is called using the iframe to be seem as they are in the same page. But the problem is that,
while updating the iframe with update pannel and timmer tick event doent work and only when unzipping process has done, it works.
i would like to update database which resides on web server from my database which is on my computer. One method is to upload the file and than make a connectionstring. But its not possible while I do so in every 10 secs.
Is there any method which can make the connection string from desktop to web server or any other way.
I am new to asp.net, so this might be a basic question. But I am struggling on this for more time... I have loaded a COM object in Server script using code behind (C#) and that COM object will trigger events in some random interval. I need to update the client page whenever I receive an event from the COM object from server side (code behind).My question is, Is there a way to make the client page do postback from the code behind(C#)? ie., The client page needs to be updated whenever an event occurs in the server. Is that possible? The com event does not trigger a postback since it only occurs in the server and not in the client.
I have built a webform as part of my project that grabs all the data out of a particular table in an Access database on the server. I have allowed the ability to update said table via the DetailsView form however when you change the details and then click on "update" it throws back an error.
No value given for one or more required parameters. Description:
An unhandled exception occurred during the execution of the current web request. Please review the stack trace for more information about the error and where it originated in the code.
Exception Details: System.Data.OleDb.OleDbException: No value given for one or more required parameters.
Source Error:
[Code]....
Stack Trace:
[Code]....
I am not sure what has happened but it simply will not allow me to update any data. Here is a copy of the select, update and delete statement.
DeleteCommand="DELETE FROM [tbl_mmstafflist] WHERE [EngID] = ? AND (([EngCode] = ?) OR ([EngCode] IS NULL AND ? IS NULL)) AND (([EngName] = ?) OR ([EngName] IS NULL AND ? IS NULL)) AND (([EmailAddress] = ?) OR ([EmailAddress] IS NULL AND ? IS NULL)) AND (([Ext No] = ?) OR ([Ext No] IS NULL AND ? IS NULL)) AND (([Mobile No] = ?) OR ([Mobile No] IS NULL AND ? IS NULL)) AND (([Home No] = ?) OR ([Home No] IS NULL AND ? IS NULL)) AND (([Address 1] = ?) OR ([Address 1] IS NULL AND ? IS NULL)) AND (([Address 2] = ?) OR ([Address 2] IS NULL AND ? IS NULL)) AND (([Address 3] = ?) OR ([Address 3] IS NULL AND ? IS NULL)) AND (([Town] = ?) OR ([Town] IS NULL AND ? IS NULL)) AND (([County] = ?) OR ([County] IS NULL AND ? IS NULL)) AND (([Postcode] = ?) OR ([Postcode] IS NULL AND ? IS NULL)) AND (([Other email address] = ?) OR ([Other email address] IS NULL AND ? IS NULL)) AND [Visa card] = ? AND [Ex staff] = ? AND (([ExternalDirectDialNumber] = ?) OR ([ExternalDirectDialNumber] IS NULL AND ? IS NULL)) AND (([PayrollNumber] = ?) OR ([PayrollNumber] IS NULL AND ? IS NULL)) AND [NeedstoSeekApproval] = ? AND [IsStockController] = ? AND (([Group] = ?) OR ([Group] IS NULL AND ? IS NULL)) AND (([ContractedWeeklyHours] = ?) OR ([ContractedWeeklyHours] IS NULL AND ? IS NULL)) AND (([Grade] = ?) OR ([Grade] IS NULL AND ? IS NULL)) AND (([IP] = ?) OR ([IP] IS NULL AND ? IS NULL)) AND (([StaffTitle] = ?) OR ([StaffTitle] IS NULL AND ? IS NULL))"
OldValuesParameterFormatString="original_{0}" SelectCommand="SELECT * FROM [tbl_mmstafflist] where ([EngID] = @EngID)" UpdateCommand ="UPDATE [tbl_mmstafflist] SET [EngCode] = ?, [EngName] = ?, [EmailAddress] = ?, [Ext No] = ?, [Mobile No] = ?, [Home No] = ?, [Address 1] = ?, [Address 2] = ?, [Address 3] = ?, [Town] = ?, [County] = ?, [Postcode] = ?, [Other email address] = ?, [Visa card] = ?, [Ex staff] = ?, [ExternalDirectDialNumber] = ?, [PayrollNumber] = ?, [NeedstoSeekApproval] = ?, [IsStockController] = ?, [Group] = ?, [ContractedWeeklyHours] = ?, [Grade] = ?, [IP] = ?, [StaffTitle] = ? WHERE [EngID] = ? AND (([EngCode] = ?) OR ([EngCode] IS NULL AND ? IS NULL)) AND (([EngName] = ?) OR ([EngName] IS NULL AND ? IS NULL)) AND (([EmailAddress] = ?) OR ([EmailAddress] IS NULL AND ? IS NULL)) AND (([Ext No] = ?) OR ([Ext No] IS NULL AND ? IS NULL)) AND (([Mobile No] = ?) OR ([Mobile No] IS NULL AND ? IS NULL)) AND (([Home No] = ?) OR ([Home No] IS NULL AND ? IS NULL)) AND (([Address 1] = ?) OR ([Address 1] IS NULL AND ? IS NULL)) AND (([Address 2] = ?) OR ([Address 2] IS NULL AND ? IS NULL)) AND (([Address 3] = ?) OR ([Address 3] IS NULL AND ? IS NULL)) AND (([Town] = ?) OR ([Town] IS NULL AND ? IS NULL)) AND (([County] = ?) OR ([County] IS NULL AND ? IS NULL)) AND (([Postcode] = ?) OR ([Postcode] IS NULL AND ? IS NULL)) AND (([Other email address] = ?) OR ([Other email address] IS NULL AND ? IS NULL)) AND [Visa card] = ? AND [Ex staff] = ? AND (([ExternalDirectDialNumber] = ?) OR ([ExternalDirectDialNumber] IS NULL AND ? IS NULL)) AND (([PayrollNumber] = ?) OR ([PayrollNumber] IS NULL AND ? IS NULL)) AND [NeedstoSeekApproval] = ? AND [IsStockController] = ? AND (([Group] = ?) OR ([Group] IS NULL AND ? IS NULL)) AND (([ContractedWeeklyHours] = ?) OR ([ContractedWeeklyHours] IS NULL AND ? IS NULL)) AND (([Grade] = ?) OR ([Grade] IS NULL AND ? IS NULL)) AND (([IP] = ?) OR ([IP] IS NULL AND ? IS NULL)) AND (([StaffTitle] = ?) OR ([StaffTitle] IS NULL AND ? IS NULL))">
The SelectParameter is used because this page is a details page that is selected from a list. I would appreciate any help that you can offer. Unfortunately Access errors are not forth coming with information.
Not sure why it works if i connect to SQL 2005 on another server, but now that i have SQL Express on the same server as the pages, im getting the following error: I have attached my connection string within my web.config and also how its being called within the code behind. Now this page was written by another programmer some time back.. so not sure if the method he used to do this is the best or only way. But i have connected to other SQL database with other applications with alot less code.
A network-related or instance-specific error occurred while establishing a connection to SQL Server. The server was not found or was not accessible. Verify that the instance name is correct and that SQL Server is configured to allow remote connections.
(provider: Named Pipes Provider, error: 40 - Could not open a connection to SQL Server)
Source Error: Line 131: Line 132: //connect to this sql server Line 133: c.Open(); -----> this is the line it complains about.[Code]....
I published my web.The problem is that the path to the DataBase is not good and i dont know how to change it.heare is the error:A network-related or instance-specific error occurred while establishing a connection to SQL Server. The server was not found or was not accessible. Verify that the instance name is correct and that SQL Server is configured to allow remote connections. (provider: SQL Network Interfaces, error: 26 - Error Locating Server/Instance Specified)
I m having a database problem that I couldnt identify. The IIS loses connection to database once in 3 weeks. Once you restart the IIS everything is normal. Looks like IIS is fine because i can go to static pages. When I go to a page that requires database connection I get this error:
A transport-level error has occurred when sending the request to the server. (provider: TCP Provider, error: 0 - Either the application has not called WSAStartup, or WSAStartup failed.
A network-related or instance-specific error occurred while establishing a connection to SQL Server. The server was not found or was not accessible. Verify that the instance name is correct and that SQL Server is configured to allow remote connections. (provider: Named Pipes Provider, error: 40 - Could not open a connection to SQL Server)
Is this a connection string problem?. because without changing anything if I restart the webserver all is fine. Is this a problem with application state?
how to catch update panel's request start (before partial updation request is sent to server) and response receive (before update panel is updated) events.
Is is possible to initiate a partial page update whenever a client makes an update (say inserrting a record) and this will update the panel of all clients who are actually viewing the page ie eliminate the use of a timer control to refresh the panel each second because am getting many problems when using timercontrol.
What is Web services? What is Web services? How can I Transfer the data from server to client and  client to server using XML. Need one simple Example program(C# web Application) ...
I have seen a few posts regarding this issue but not one specific to my problem and I have no ideas as to what I need to do to debug this.I have some combo boxes on an aspx pages, when I select a value from the first one, it fills the second with value and so on with the third and fourth. This works with no problems until I wrap an asp.net UpdatePanel around the combo boxes and try to "ajaxify" the whole process so the page isn't dancing around. The exact error I get is: Sys.WebForms.PageRequestManagerServerErrorException: An unknown error occurred while processing the request on the server. The status code returned from the server was: 404
Everything was working fine yesterday afternoon before going home.. shut down with no issues and this morning when i try to open SQL i get error message with the following, im on a deadline with this project and cant afford to lose what i have setup already. Is there anything i can do to correct whatever issues there may be?
TITLE: Connect to Server
------------------------------
Cannot connect to local.
------------------------------
ADDITIONAL INFORMATION:
A network-related or instance-specific error occurred while establishing a connection to SQL Server. The server was not found or was not accessible. Verify that the instance name is correct and that SQL Server is configured to allow remote connections. (provider: SQL Network Interfaces, error: 26 - Error Locating Server/Instance Specified) (Microsoft SQL Server, Error: -1)
I've created a small website with a simple sqlite database using vwd 2010 .net 4. In dev and test envionments everything works fine, however when i promote to my hosting provider i receive the following error:
A network-related or instance-specific error occurred while establishing a connection to SQL Server. The server was not found or was not accessible. Verify that the instance name is correct and that SQL Server is configured to allow remote connections.
I've been configuring the connection strings (autogenerated from entity framework and attached db) but unable to get it working on the hosting provider, I'm assuming it's related to permissions but not entirely sure how to resolve - here's the web.config as it stands:
I just installed sql server 2008 R2 on my computer. I am trying to connect to sql server throught my C# code and everytime I run the C# program,
I get this error "A network-related or instance-specific error occurred while establishing a connection to SQL Server.
The server was not found or was not accessible. Verify that the instance name is correct and that SQL Server is configured to allow remote connections. (provider: Named Pipes Provider, error: 40 - Could not open a connection to SQL Server) "
The connection string that I used in my web.config file is
[Code]....
I am not sure what am I doing wrong, but I followed this article below step by step and still I am getting the same error
i m running asp.net example code in my vs 2005. I am using following datasource. I have no sql express edition, but i have developer edition of sql server 2005.
[code]...
i have .mdf file and i got following error message.
A network-related or instance-specific error occurred while establishing a connection to SQL Server. The server was not found or was not accessible. Verify that the instance name is correct and that SQL Server is configured to allow remote connections. (provider: SQL Network Interfaces, error: 26 - Error Locating Server/Instance Specified)
There is a Compilation Error at the web site located at http://cforedu.comDescription: An error occurred during the compilation of a resource required to service this request. Please review the following specific error details and modify your source code appropriately.
am connecting online database in my website. whenever forms in idle one shows in server side. after refereshing that error cleared.what is the problem. that like thisA transport-level error has occurred when sending the request to the server. (provider: TCP Provider, error: 0 - An existing connection was forcibly closed by the remote host.
Am getting this error on clicking any of my page link.
Sys.WebForms.PageRequestManagerServerErrorException: An unknown error occurred while processing the request on the server. The status code returned from the server was: 0"
I recently bought domain and hosting from godaddy.com and uploaded my website files based on asp.net on server.
The problem is when i run Default.aspx file in visual studio it runs properly but same set set of files when ran after uploading on server gives error in web.config file.
Description:Â An application error occurred on the server. The current custom error settings for this application prevent the details of the application error from being viewed remotely (for security reasons). It could, however, be viewed by browsers running on the local server machine.
Details:Â Â To enable the details of this specific error message to be viewable on remote machines, please create a <customErrors> tag within a "web.config" configuration file located in the root directory of the current web application. This <customErrors> tag should then have its "mode" attribute set to "Off".
<?xml version="1.0"?> <!-- Note: As an alternative to hand editing this file you can use the web admin tool to configure settings for your application. Use the Website->Asp.Net Configuration option in Visual Studio. A full list of settings and comments can be found in machine.config.comments usually located in WindowsMicrosoft.NetFrameworkv2.xConfig -->
if in the code behind, I set the label to "You must enter a value if the textbox is empty" to validate it on the server side and this is fine, but if javascript is enabled, I don't want to show the client side validation and the server side label together. Is this something where I would just have to disable the client-side validators if javascript was enabled?
