在優(yōu)酷上我想上傳一段視頻，你有想過(guò)會(huì)臺(tái)是怎么實(shí)現(xiàn)的嗎？這里我就為大家分析一下關(guān)于利用WCF上傳文件，在WCF沒(méi)出現(xiàn)之前，我一直使用用WebService來(lái)上傳文件，我不知道別人為什么要這么做，因?yàn)槲覀兊奈募?wù)器和網(wǎng)站后臺(tái)和網(wǎng)站前臺(tái)都不在同一個(gè)機(jī)器，操作人員覺(jué)得用FTP傳文件太麻煩，我就做一個(gè)專門(mén)用來(lái)上傳文件的WebService,把這個(gè)WebService部署在文件服務(wù)器上，然后在網(wǎng)站后臺(tái)調(diào)用這個(gè)WebService，把網(wǎng)站后臺(tái)頁(yè)面上傳上來(lái)的文件轉(zhuǎn)化為字節(jié)流傳給WebService，然后WebService把這個(gè)字節(jié)流保存文件到一個(gè)只允許靜態(tài)頁(yè)面的網(wǎng)站（靜態(tài)網(wǎng)站可以防止一些腳本木馬）。

#T#WebService來(lái)上傳文件存在的問(wèn)題是效率不高，而且不能傳輸大數(shù)據(jù)量的文件，當(dāng)然你可以用Wse中的MTOM來(lái)傳輸大文件，有了WCF就好多了，通過(guò)使用WCF傳遞Stream對(duì)象來(lái)傳遞大數(shù)據(jù)文件，但有一些限制：只有BasicHttpBinding、NetTcpBinding和NetNamedPipeBinding支持傳送流數(shù)據(jù)。流數(shù)據(jù)類型必須是可序列化的Stream或MemoryStream。傳遞時(shí)消息體(MessageBody)中不能包含其他數(shù)據(jù)。TransferMode的限制和MaxReceivedMessageSize的限制等。

下面具體實(shí)現(xiàn)：新建一個(gè)WCFService，接口文件的代碼如下：

[ServiceContract]  
publicinterfaceIUpLoadService  
{  
[OperationContract(Action="UploadFile",IsOneWay=true)]  
voidUploadFile(FileUploadMessagerequest);  
}  
[MessageContract]  
publicclassFileUploadMessage  
{  
[MessageHeader(MustUnderstand=true)]  
publicstringSavePath;  
[MessageHeader(MustUnderstand=true)]  
publicstringFileName;  
[MessageBodyMember(Order=1)]  
publicStreamFileData;  
} 

定義FileUploadMessage類的目的是因?yàn)榈谌齻€(gè)限制，要不然文件名和存放路徑就沒(méi)辦法傳遞給WCF了，根據(jù)第二個(gè)限制，文件數(shù)據(jù)是用System.IO.Stream來(lái)傳遞的接口方法只有一個(gè)，就是WCF上傳文件，注意方法參數(shù)是FileUploadMessage接口實(shí)現(xiàn)類文件的代碼如下：

publicclassUpLoadService:IUpLoadService  
{  
publicvoidUploadFile(FileUploadMessagerequest)  
{  
stringuploadFolder=@"C:\kkk\";  
stringsavaPath=request.SavePath;  
stringdateString=DateTime.Now.ToShortDateString()+@"\";  
stringfileName=request.FileName;  
StreamsourceStream=request.FileData;  
FileStreamtargetStream=null;  
if(!sourceStream.CanRead)  
{  
thrownewException("數(shù)據(jù)流不可讀!");  
}  
if(savaPath==null)savaPath=@"Photo\";  
if(!savaPath.EndsWith("\\"))savaPath+="\\";  
 
uploadFolderuploadFolder=uploadFolder+savaPath+dateString;  
if(!Directory.Exists(uploadFolder))  
{  
Directory.CreateDirectory(uploadFolder);  
}  
stringfilePath=Path.Combine(uploadFolder,fileName);  
using(targetStream=newFileStream(filePath,FileMode.Create,FileAccess.Write,FileShare.None))  
{  
//readfromtheinputstreamin4Kchunks  
//andsavetooutputstream  
constintbufferLen=4096;  
byte[]buffer=newbyte[bufferLen];  
intcount=0;  
while((count=sourceStream.Read(buffer,0,bufferLen))>0)  
{  
targetStream.Write(buffer,0,count);  
}  
targetStream.Close();  
sourceStream.Close();  
}  
}  
}  

實(shí)現(xiàn)的功能是到指定目錄下按照日期進(jìn)行目錄劃分，然后以傳過(guò)來(lái)的文件名保存文件。這篇文章最主要的地方就是下面的Web.Config配置：

<system.serviceModel> 
<bindings> 
<basicHttpBinding> 
<bindingnamebindingname="FileTransferServicesBinding"maxReceivedMessageSize="9223372036854775807"  
messageEncoding="Mtom"transferMode="Streamed"sendTimeout="00:10:00"/> 
</basicHttpBinding> 
</bindings> 
<services> 
<servicebehaviorConfigurationservicebehaviorConfiguration="UploadWcfService.UpLoadServiceBehavior" 
name="UploadWcfService.UpLoadService"> 
<endpointaddressendpointaddress=""binding="basicHttpBinding"bindingConfiguration="FileTransferServicesBinding"contract="UploadWcfService.IUpLoadService"> 
</endpoint> 
<endpointaddressendpointaddress="mex"binding="mexHttpBinding"contract="IMetadataExchange"/> 
</service> 
</services> 
<behaviors> 
<serviceBehaviors> 
<behaviornamebehaviorname="UploadWcfService.UpLoadServiceBehavior"> 
<serviceMetadatahttpGetEnabledserviceMetadatahttpGetEnabled="true"/> 
<serviceDebugincludeExceptionDetailInFaultsserviceDebugincludeExceptionDetailInFaults="false"/> 
</behavior> 
</serviceBehaviors> 
</behaviors> 
</system.serviceModel>