cannot access a closed file – FileUpload in ASP.NET

Author posted by Jitendra on Posted on under category Categories ASP.NET and tagged as Tags , with 16 Comments on cannot access a closed file – FileUpload in ASP.NET

This was very interesting error, i got during development of file upload control in ASP.NET.

On my local system, every thing was just fine. but when i deployed my application on development server, my control was able to upload only small size files.

whenever i tried to upload large size file i got error “cannot access a closed file”

After going through MSDN i found that there is one new element added in ASP.NET 2.0 known as httpRuntime.

So i just added this new Tag in my web.config and every thing was right.

<system.web>
<httpRuntime  maxRequestLength="15360" requestLengthDiskThreshold="15360"/>
</system.web>

Note :

requestLengthDiskThreshold should not exceed the maxRequestLengthattribute.

To read more about this, please visit http://msdn.microsoft.com/en-us/library/e1f13641(VS.80).aspx

XML Parsing Error: no element found

Author posted by Jitendra on Posted on under category Categories ASP.NET, Tech Tips and tagged as Tags , with 3 Comments on XML Parsing Error: no element found

Few Days ago, i found strange error like “XML Parsing Error: no element found“.

I was unable to find the exact root cause. Most of the times it happens if you are missing any closing tag in your ASPZ application. I checked my complete page and reconfirmed but error still persist.

somehow i found that ASP.NET treat the response of page as XML document and that’s why we receive XML Parsing Error: no element found error.

so explicitly i set the response type of my page as text/HTML. Response.ContentType = “text/HTML”.

And this line tells the ASPX that page is HTML, not XML.

ASP.Net Error: Response is not available in this context

Author posted by Jitendra on Posted on under category Categories ASP.NET and tagged as Tags with 2 Comments on ASP.Net Error: Response is not available in this context

This error occurred when  i tried to call Response.Redirect method from a class file. Then i tried to find the solution and i got to know that when we use the response object from an aspx page either from aspx page or it’s codebehind page, the response object is directly available because all these derived from the page object.

When we use the response object in our own class, the object is not directly available, so we got this message.

But we can use it by the following method :

HttpContext.Current.Response.Redirect(http://google.com“);

Same problem happens when we tried to call a function from Response object.

Thank You.

App_Offline.htm in ASP.NET

Author posted by Jitendra on Posted on under category Categories ASP.NET and tagged as Tags with 1 Comment on App_Offline.htm in ASP.NET

If you place a file with the name App_Offline.htm in the root of a web application directory, ASP.NET 2.0 will shut-down the application, unload the application domain from the server, and stop processing any new incoming requests for that application.

ASP.NET will also then respond to all requests for dynamic pages in the application by sending back the content of the App_offline.htm file (for example: you might want to have a “site under construction” or “down for maintenance” message).

Once you remove the App_offline.htm file, the next request into the application will cause ASP.NET to load the application and app-domain again, and it will be back to normal.

If you place a file with the name App_Offline.htm in the root of a web application directory, ASP.NET 2.0 will shut-down the application, unload the application domain from the server, and stop processing any new incoming requests for that application.

ASP.NET will also then respond to all requests for dynamic pages in the application by sending back the content of the App_offline.htm file (for example: you might want to have a “site under construction” or “down for maintenance” message).

Once you remove the App_offline.htm file, the next request into the application will cause ASP.NET to load the application and app-domain again, and it will be back to normal.

Limitation:

Note that the file must be at least 512kb in size or it will not work. This a well known ‘limitation’.

Use FXcop with ASP.NET

Author posted by Jitendra on Posted on under category Categories ASP.NET and tagged as Tags , with Leave a comment on Use FXcop with ASP.NET

FxCop, an abbreviation “Framework Police,” is a rules-based engine that checks managed code assemblies for Microsoft’s .NET Framework design guidelines and custom guidelines. FxCop is a rule based engine which helps the development team to follow best practices of the .NET platform and development standards (based on every company standards).
You can apply to any assembly which been created using any language that target Microsoft.NET managed environment.

Advantages:

1.Make sure coding standards follow such as naming conventions, globalization etc. as per company standards.
2. Avoid bad coding. (No one write bad code however as the application grows development team size also grow usually so ever new team member must know how to design their classes, follow naming convention etc.).
3. Predefined set of rules.
4. Support for creating custom rules.
5. Generate formatted XML Analysis Report.

To use FxCop with ASP.NET, follow below steps:

Go to

C:WINDOWSMicrosoft.NETFrameworkv2.0.50727Temporary ASP.NET FilesMyTest

Where MyTest is your project folder

Select details view from Explorer so you can see which folder is the newer folder and open it up

Select details view again and hunt down the App_Web dll file that is the latest e.g.

App_Web_cxauo9ex.dll

You can then add this as a target in your FxCop project.