C#中，用Web頁上傳檔案大小限制的問題

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,或者是其他元件比如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,一般可以自定義最大檔案大小. <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。為什麼？因為這是個client side錯誤，server side端的Application_Error是處理不到的， 可以參考這個帖子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，還能實時顯示上傳進度： 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)

這次在專案中，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 元件發現用的比較多的有兩個控制元件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 兩個控制元件的方法是：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，還能實時顯示上傳進度。 Lion.Web.UpLoadModule和AspnetUpload 兩個.NET元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 轉載自http://community.csdn.net/Expert/topic/4117/4117836.xml?temp=.5636865