Use. NET file control upload files to the final Solution

Solution | control | upload

After traversing all the posts about uploading large files in csdn, I wrote this piece of rubbish. (:-))
There are several ways to upload large files:
1, Shi HttpWorkerRequest method, too difficult, can not understand:-(
2, the use of Third-party control aspnetupload want Money!! Forget it, we still like it for free.
3, modify the Web.config file, but can not catch errors.
4, through the way of FTP upload. The server needs to provide an FTP service.

Have to choose a third way, who let us too stupid! (Too stupid, no relationship, to eat more fish, I heard that eating fish can be smart point.) )

Then carefully research the third way!

To modify the Webcong file:
<system.web>
Usefullyqualifiedredirecturl= "true"
executiontimeout= "6000"
Usefullyqualifiedredirecturl= "false"
Minfreethreads= "8"
Minlocalrequestfreethreads= "4"
apprequestqueuelimit= "100"
Enableversionheader= "true"
/>
</system.web>

Which is closely related to the upload is:
maxRequestLength
Indicates the maximum file upload size supported by asp.net.
This restriction can be used to prevent denial of service attacks caused by a user passing a large number of files to the server.
The specified size is in kilobytes.
The default value is 4096 KB (4 MB).

Executiontimeout
Indicates the maximum number of seconds allowed to execute a request before it is automatically closed by asp.net.
The unit is seconds, and when uploading large files, set this up a bit larger.

If the server memory is 512M, you can upload files of size 160M. (haven't tried, csdn the unanimous opinion of the public posts.) )

The setting of the web.config here is over.
However, once the size of the uploaded file exceeds the file size of this setting, the following error occurs:
The page cannot be displayed
The page you are looking for is currently unavailable. Your web site may be experiencing technical problems, or you need to adjust your browser settings.

Although cannot solve, that also must catch this mistake! What do we do?
Recently ate a few fish, think about, because this error is caused by the file control foreground error, so in the background want to use Try...catch to capture is not feasible.
So I thought of using. NET error capture page mechanism to deal with. Yes, it works.

1, first set web.config
<customerrors mode= "on"/>
2, create a new error.aspx file, specifically to catch the wrong.
3. Add page directives to the front page of the ASPX page of the uploaded file. Errorpage= "Uploaderror.aspx"
4. Add some code in the error.aspx to determine if the error message is a foreground error caused by file.
public class UploadError:System.Web.UI.Page
{
private void Page_Load (object sender, System.EventArgs e)
{
Exception ex = Server.GetLastError ();
if (ex!= null)
{
Response.Redirect (".. /error.aspx ");
}
else//Foreground error ex is null
{
Response.Redirect ("Uploadexcel.aspx?err=1"); Re-jump to upload page, plus err parameter to display error message
}
}

5, display error prompts.
public class Uploadexcel:System.Web.UI.Page
{
private void Page_Load (object sender, System.EventArgs e)
{
if (request["err"] = = "1")
{
Page.registerstartupscript ("Budget", "<script language = Javascript>alert (' Upload file has failed!") File size is too large! ') </script> ");
}
}
}

6, finish the work. (This fish is not free.)

After the above changes, now the upload has become, the program specifies the file size, if more than, then pop-up error prompts.
In this way, much better, at least they can accept, and the user explanation is not too strenuous.