IOSAndWCF上传文件

2019-11-14 19:40:45

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IOS And WCF Story

研究IOS上传到WCF图片的小功能，WCF实现服务端的文件上传的例子很多，单独实现IOS发送图片的例子也很多，但是两个结合起来的就很少了。
可以通过base64来上传图片，这个方式比较简单，但是我想要的是通过网络流来传送，这样以后IOS发送任何的文件，服务器不需要修改就能直接来用。想法很简单，但是历程很辛苦。。。

IOS发送

首先研究一下IOS端的图片传输，我用的网络框架是AFNetWorking，附上代码

NSString *filename=@"test.jpg";AFHTTPRequestOperationManager *AFManager=[[AFHTTPRequestOperationManager alloc]initWithBaseURL:[NSURL URLWithString:@FileTranUrl]];AFHTTPRequestOperation *operation=[AFManager POST:path parameters:nil constructingBodyWithBlock:^(id<AFMultipartFormData> formdata){[formdata appendPartWithFileData:imagedata name:name fileName:filename mimeType:@"image/jpeg"];} success:^(AFHTTPRequestOperation *operation, id responSEObject) {    if (success) {        success(operation,responseObject);    }} failure:^(AFHTTPRequestOperation *operation, NSError *error) {    if (failure) {        failure(operation,error);    }}];

imagedata是image转换为NSdata后的值。

这里的代码看起来很多，其实很简单，关键只有一处就是

[formdata appendPartWithFileData:imagedata name:name fileName:filename mimeType:@"image/jpeg"];

AFMultipartFormData 做了什么呢？

查看它的appendPartWithFileData:name:filename:mimeType:源代码，我们可以看到

- (void)appendPartWithFileData:(NSData *)data                      name:(NSString *)name                  fileName:(NSString *)fileName                  mimeType:(NSString *)mimeType{  NSParameterAssert(name);  NSParameterAssert(fileName);  NSParameterAssert(mimeType);  NSMutableDictionary *mutableHeaders = [NSMutableDictionary dictionary];  [mutableHeaders setValue:[NSString stringWithFormat:@"form-data; name=/"%@/"; filename=/"%@/"", name, fileName] forKey:@"Content-Disposition"];  [mutableHeaders setValue:mimeType forKey:@"Content-Type"];  [self appendPartWithHeaders:mutableHeaders body:data];}

multableHeaders包含了name,filename,mimeType再次查看最后一个方法的定义

 - (void)appendPartWithHeaders:(NSDictionary *)headers                     body:(NSData *)body{    NSParameterAssert(body);    AFHTTPBodyPart *bodyPart = [[AFHTTPBodyPart alloc] init];    bodyPart.stringEncoding = self.stringEncoding;    bodyPart.headers = headers;    bodyPart.boundary = self.boundary;    bodyPart.bodyContentLength = [body length];    bodyPart.body = body;    [self.bodyStream appendHTTPBodyPart:bodyPart];}

[self.bodyStream appendHTTPBodyPart:bodyPart];看到这里的时候我们已经明白了，以上所有包含的数据全部放到网络流里了。为什么要查看这些呢？因为WCF需要契约定义，我们不知道AFNetwork发送的时候我们应该用什么契约来接受这个方法。

WCF接受

通过上面的分析，我们已经大概知道契约的定义了

void(Stream requestStream)

WCF在接受数据之前还需要进行配置，在

<system.serviceModel><bindings>  <webHttpBinding>    <binding name="WebConfiguration"             maxBufferSize="65536"             maxReceivedMessageSize="2000000000"             transferMode="Streamed">    </binding>  </webHttpBinding>  </bindings><services>        <!--文件服务-->  <service name="WcfServiceForIOS.ServiceForIOSFile" behaviorConfiguration="ServiceBehavior">    <endpoint address=""  binding="webHttpBinding" behaviorConfiguration="web"   bindingConfiguration="WebConfiguration"  contract="WcfServiceForIOS.IServiceForIOSFile" />  </service>  </services><behaviors>  <endpointBehaviors>    <behavior name="web">      <webHttp />    </behavior>  </endpointBehaviors>  <serviceBehaviors>    <behavior name="ServiceBehavior">      <serviceMetadata httpGetEnabled="true" />      <serviceDebug includeExceptionDetailInFaults="false" />    </behavior>        </serviceBehaviors></behaviors></system.serviceModel>

尝试实现契约的主要代码

using (targetStream = new FileStream(filePathAndName, FileMode.Create, Fileaccess.Write, FileShare.None)){   const int bufferLen = 4096;   Byte[] buffer = new Byte[bufferLen];  int count = 0;   while ((count = sourceStream.Read(buffer, 0, bufferLen)) > 0)    {     targetStream.Write(buffer, 0, count);     filesize += count;    }    targetStream.Close();    sourceStream.Close();                                          }

等IOS上传图片后，可以在相应的文件夹中找到生成的图片，但是不幸的是我们无法打开，提示图片损坏太大。用NotePad++打开这个文件流，可以看到以下代码

--Boundary+4AA85CFEE4A1D140Content-Disposition: form-data; name="file"; filename="test.jpg"Content-Type: image/jpeg（乱码，目测是图片的数据流）--Boundary+4AA85CFEE4A1D140--

是不是和发送时候的很眼熟，这样和前面的分析就对上了，传输过来的文件流是包含图片的信息和图片的数据。需要分开处理。
处理方法和web发送的form-data是一样的，先编码为string，通过正则表达取出各个属性值

 private void Parse(Stream stream, Encoding encoding)    {        this.Success = false;        // Read the stream into a byte array        byte[] data = ToByteArray(stream);        requestData = data;        // Copy to a string for header parsing        string content = encoding.GetString(data);        // The first line should contain the delimiter        int delimiterEndIndex = content.IndexOf("/r/n");        if (delimiterEndIndex > -1)        {            string delimiter = content.Substring(0, content.IndexOf("/r/n"));            // Look for Content-Type            Regex re = new Regex(@"(?<=Content/-Type:)(.*?)(?=/r/n/r/n)");            Match contentTypeMatch = re.Match(content);            // Look for filename            re = new Regex(@"(?<=filename/=/"")(.*?)(?=/"")");            Match filenameMatch = re.Match(content);            // Did we find the required values?            if (contentTypeMatch.Success && filenameMatch.Success)            {                // Set properties                this.ContentType = contentTypeMatch.Value.Trim();                this.Filename = filenameMatch.Value.Trim();                // Get the start & end indexes of the file contents                int startIndex = contentTypeMatch.Index + contentTypeMatch.Length + "/r/n/r/n".Length;                byte[] delimiterBytes = encoding.GetBytes("/r/n" + delimiter);                int endIndex = IndexOf(data, delimiterBytes, startIndex);                int contentLength = endIndex - startIndex;                // Extract the file contents from the byte array                byte[] fileData = new byte[contentLength];                Buffer.BlockCopy(data, startIndex, fileData, 0, contentLength);                this.FileContents = fileData;                this.Success = true;            }        }    }

取出各个段后就能用来存文件了