運用asp.net上傳大檔案

ASP.NET裡面,上傳最大的檔案,可能在225M以下,再大,如何修改都不行.
預設的上傳大小是4M.
如果需要上傳更大的檔案,必須採用其他方法.比如FTP,或者是其他組件比如ASPUPLOAD(不知道有沒有NET版),還有,以下地址是討論在NET中超大檔案上傳的,你可以去看看.

下面是一些資料,你可參考一下(上面所述地址也在裡面)

對於asp.net,預設只允許上傳2M檔案,增加如下配置,一般可以自訂最大檔案大小.
<httpRuntime
executionTimeout="300"
maxRequestLength="40960"
useFullyQualifiedRedirectUrl="false"/>

如果還不行,可以使用思歸提供的方案:
我們在上傳大檔案時都遇到過這樣或那樣的問題。設定很大的maxRequestLength值並不能完全解決問題，
因為ASP.NET會block直到把整個檔案載入記憶體後，再加以處理。實際上，如果檔案很大的話，
我們經常會見到Internet Explorer顯示 "The page cannot be displayed - Cannot find server or DNS Error"，
好像是怎麼也catch不了這個錯誤。為什嗎？因為這是個client side錯誤，server side端的Application_Error是處理不到的，
可以參考這個文章研究一下產生這個錯誤的機理。
handling server error when upload file too large
解決的方法是利用隱含的HttpWorkerRequest，用它的GetPreloadedEntityBody 和 ReadEntityBody方法從IIS為ASP.NET建立的
pipe裡分塊讀取資料

IServiceProvider provider = (IServiceProvider) HttpContext.Current;

HttpWorkerRequest wr = (HttpWorkerRequest) provider.GetService(typeof(HttpWorkerRequest));
byte[] bs = wr.GetPreloadedEntityBody();
....
if (!wr.IsEntireEntityBodyIsPreloaded())
{
int n = 1024;
byte[] bs2 = new byte[n];
while (wr.ReadEntityBody(bs2,n) >0)
{
.....
}
}
Chris Hynes為我們提供了這樣的一個方案(用HttpModule)，該方案除了允許你上傳大檔案外，還能即時顯示上傳進度：
ASP.NET Upload Magic Part 2
這裡有他講座的PPT檔案：
Uploading with ASP.NET (part 1)
Uploading with ASP.NET (part 2)

 

這次在項目中，用到了大檔案上傳，要上傳的檔案有100多m，於是研究現在國內使用的大檔案上傳的
組件發現用的比較多的有兩個控制項AspnetUpload 2.0和Lion.Web.UpLoadModule，另外還有思歸在它的部落格
堂中所說的辦法 http://blog.joycode.com/saucer/archive/2004/03/16/16225.aspx
兩個控制項的方法是：利用隱含的HttpWorkerRequest，用它的GetPreloadedEntityBody 和 ReadEntityBody方法從IIS為ASP.NET建立的pipe裡分塊讀取資料。Chris Hynes為我們提供了這樣的一個方案(用HttpModule)，該方案除了允許你上傳大檔案外，還能即時顯示上傳進度。
Lion.Web.UpLoadModule和AspnetUpload 兩個.NET組件都是利用的這個方案。
當上傳單檔案時，兩個軟體的方法是一樣的，繼承HttpModule
HttpApplication application1 = sender as HttpApplication;
HttpWorkerRequest request1 = (HttpWorkerRequest) ((IServiceProvider) HttpContext.Current).GetService(typeof(HttpWorkerRequest));
try
{
if (application1.Context.Request.ContentType.IndexOf("multipart/form-data") <= -1)
{
return;
}
//Check The HasEntityBody
if (!request1.HasEntityBody())
{
return;
}

int num1 = 0;
TimeSpan span1 = DateTime.Now.Subtract(this.beginTime);

string text1 = application1.Context.Request.ContentType.ToLower();

byte[] buffer1 = Encoding.ASCII.GetBytes(("\r\n--" + text1.Substring(text1.IndexOf("boundary=") + 9)).ToCharArray());
int num2 = Convert.ToInt32(request1.GetKnownRequestHeader(11));
Progress progress1 = new Progress();

application1.Context.Items.Add("FileList", new Hashtable());

byte[] buffer2 = request1.GetPreloadedEntityBody();
num1 += buffer2.Length;

string text2 = this.AnalysePreloadedEntityBody(buffer2, "UploadGUID");
if (text2 != string.Empty)
{
application1.Context.Items.Add("LionSky_UpLoadModule_UploadGUID", text2);
}
bool flag1 = true;
if ((num2 > this.UpLoadFileLength()) && ((0 > span1.TotalHours) || (span1.TotalHours > 3)))
{
flag1 = false;
}
if ((0 > span1.TotalHours) || (span1.TotalHours > 3))
{
flag1 = false;
}
string text3 = this.AnalysePreloadedEntityBody(buffer2, "UploadFolder");
ArrayList list1 = new ArrayList();
RequestStream stream1 = new RequestStream(buffer2, buffer1, null, RequestStream.FileStatus.Close, RequestStream.ReadStatus.NoRead, text3, flag1, application1.Context, string.Empty);
list1.AddRange(stream1.ReadBody);
if (text2 != string.Empty)
{
progress1.FileLength = num2;
progress1.ReceivedLength = num1;
progress1.FileName = stream1.OriginalFileName;
progress1.FileCount = ((Hashtable) application1.Context.Items["FileList"]).Count;
application1.Application["_UploadGUID_" + text2] = progress1;
}
if (!request1.IsEntireEntityBodyIsPreloaded())
{
byte[] buffer4;
ArrayList list2;
int num3 = 204800;
byte[] buffer3 = new byte[num3];
while ((num2 - num1) >= num3)
{
if (!application1.Context.Response.IsClientConnected)
{
this.ClearApplication(application1);
}
num3 = request1.ReadEntityBody(buffer3, buffer3.Length);
num1 += num3;
list2 = stream1.ContentBody;
if (list2.Count > 0)
{
buffer4 = new byte[list2.Count + buffer3.Length];
list2.CopyTo(buffer4, 0);
buffer3.CopyTo(buffer4, list2.Count);
stream1 = new RequestStream(buffer4, buffer1, stream1.FileStream, stream1.FStatus, stream1.RStatus, text3, flag1, application1.Context, stream1.OriginalFileName);
}
else
{
stream1 = new RequestStream(buffer3, buffer1, stream1.FileStream, stream1.FStatus, stream1.RStatus, text3, flag1, application1.Context, stream1.OriginalFileName);
}
list1.AddRange(stream1.ReadBody);
if (text2 != string.Empty)
{
progress1.ReceivedLength = num1;
progress1.FileName = stream1.OriginalFileName;
progress1.FileCount = ((Hashtable) application1.Context.Items["FileList"]).Count;
application1.Application["_UploadGUID_" + text2] = progress1;
}
}
buffer3 = new byte[num2 - num1];
if (!application1.Context.Response.IsClientConnected && (stream1.FStatus == RequestStream.FileStatus.Open))
{
this.ClearApplication(application1);
}
num3 = request1.ReadEntityBody(buffer3, buffer3.Length);
list2 = stream1.ContentBody;
if (list2.Count > 0)
{
buffer4 = new byte[list2.Count + buffer3.Length];
list2.CopyTo(buffer4, 0);
buffer3.CopyTo(buffer4, list2.Count);
stream1 = new RequestStream(buffer4, buffer1, stream1.FileStream, stream1.FStatus, stream1.RStatus, text3, flag1, application1.Context, stream1.OriginalFileName);
}
else
{
stream1 = new RequestStream(buffer3, buffer1, stream1.FileStream, stream1.FStatus, stream1.RStatus, text3, flag1, application1.Context, stream1.OriginalFileName);
}
list1.AddRange(stream1.ReadBody);
if (text2 != string.Empty)
{
progress1.ReceivedLength = num1 + buffer3.Length;
progress1.FileName = stream1.OriginalFileName;
progress1.FileCount = ((Hashtable) application1.Context.Items["FileList"]).Count;
if (flag1)
{
progress1.UploadStatus = Progress.UploadStatusEnum.Uploaded;
}
else
{
application1.Application.Remove("_UploadGUID_" + text2);
}
}
}
byte[] buffer5 = new byte[list1.Count];
list1.CopyTo(buffer5);
this.PopulateRequestData(request1, buffer5);
}
catch (Exception exception1)
{
this.ClearApplication(application1);
throw exception1;
}

而思歸所說的方法使用Mime也能上傳大檔案，在以下地址下載
http://krystalware.com/files/slickupload.zip
不過覺得的思歸的方法容易很多

More:http://community.csdn.net/Expert/topic/4093/4093569.xml?temp=.9714624