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+4AA85CFEE4A1D140
Content-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("
");
if (delimiterEndIndex > -1)
{
string delimiter = content.Substring(0, content.IndexOf("
"));
// Look for Content-Type
Regex re = new Regex(@"(?<=Content-Type:)(.*?)(?=
)");
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 + "
".Length;
byte[] delimiterBytes = encoding.GetBytes("
" + 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