如何使用WCF 4.0模板(REST)上传文件

下面显示了如何将文件上传到REST服务的示例：

private byte[] UseWebClientForFileUpload(string serviceBaseUrl, String resourceUrl, string filePath)
    {
        var c = new WebClient();
        c.OpenWrite(string.Concat(serviceBaseUrl, resourceUrl), "POST");
        c.Headers[HttpRequestHeader.ContentType] = "application/octet-stream";            
        return c.UploadFile(string.Concat(serviceBaseUrl, resourceUrl), filePath);
    }

请确保设置适当的内容类型。我认为当使用Stream作为参数之一时，我们不能传递多个参数，所以为了获得文件名和流，只需将所有内容作为一个流传递，然后使用一个解析器来分离流。有一种叫做multipartParser的东西，如下所示：

public class MultipartParser
    {
        public MultipartParser(Stream stream)
        {
            this.Parse(stream, Encoding.UTF8);
            ParseParameter(stream, Encoding.UTF8);
        }
        public MultipartParser(Stream stream, Encoding encoding)
        {
            this.Parse(stream, encoding);
        }
        private void Parse(Stream stream, Encoding encoding)
        {
            this.Success = false;
            // Read the stream into a byte array
            byte[] data = ToByteArray(stream);
            // 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;
                }
            }
        }
        private void ParseParameter(Stream stream, Encoding encoding)
        {
            this.Success = false;
            // Read the stream into a byte array
            byte[] data = ToByteArray(stream);
            // 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"));
                string[] splitContents = content.Split(new[] {delimiter}, StringSplitOptions.RemoveEmptyEntries);
                foreach (string t in splitContents)
                {
                    // Look for Content-Type
                    Regex contentTypeRegex = new Regex(@"(?<=Content'-Type:)(.*?)(?='r'n'r'n)");
                    Match contentTypeMatch = contentTypeRegex.Match(t);
                    // Look for name of parameter
                    Regex re = new Regex(@"(?<=name'='"")(.*)");
                    Match name = re.Match(t);
                    // Look for filename
                    re = new Regex(@"(?<=filename'='"")(.*?)(?='"")");
                    Match filenameMatch = re.Match(t);
                    // Did we find the required values?
                    if (name.Success || filenameMatch.Success)
                    {
                        // Set properties
                        //this.ContentType = name.Value.Trim();
                        int startIndex;
                        if (filenameMatch.Success)
                        {
                            this.Filename = filenameMatch.Value.Trim();
                        }
                        if(contentTypeMatch.Success)
                        {
                            // Get the start & end indexes of the file contents
                            startIndex = contentTypeMatch.Index + contentTypeMatch.Length + "'r'n'r'n".Length;
                        }
                        else
                        {
                            startIndex = name.Index + name.Length + "'r'n'r'n".Length;
                        }
                        //byte[] delimiterBytes = encoding.GetBytes("'r'n" + delimiter);
                        //int endIndex = IndexOf(data, delimiterBytes, startIndex);
                        //int contentLength = t.Length - startIndex;
                        string propertyData = t.Substring(startIndex - 1, t.Length - startIndex);
                        // Extract the file contents from the byte array
                        //byte[] paramData = new byte[contentLength];
                        //Buffer.BlockCopy(data, startIndex, paramData, 0, contentLength);
                        MyContent myContent = new MyContent();
                        myContent.Data = encoding.GetBytes(propertyData);
                        myContent.StringData = propertyData;
                        myContent.PropertyName = name.Value.Trim();
                        if (MyContents == null)
                            MyContents = new List<MyContent>();
                        MyContents.Add(myContent);
                        this.Success = true;
                    }
                }
            }
        }
        private int IndexOf(byte[] searchWithin, byte[] serachFor, int startIndex)
        {
            int index = 0;
            int startPos = Array.IndexOf(searchWithin, serachFor[0], startIndex);
            if (startPos != -1)
            {
                while ((startPos + index) < searchWithin.Length)
                {
                    if (searchWithin[startPos + index] == serachFor[index])
                    {
                        index++;
                        if (index == serachFor.Length)
                        {
                            return startPos;
                        }
                    }
                    else
                    {
                        startPos = Array.IndexOf<byte>(searchWithin, serachFor[0], startPos + index);
                        if (startPos == -1)
                        {
                            return -1;
                        }
                        index = 0;
                    }
                }
            }
            return -1;
        }
        private byte[] ToByteArray(Stream stream)
        {
            byte[] buffer = new byte[32768];
            using (MemoryStream ms = new MemoryStream())
            {
                while (true)
                {
                    int read = stream.Read(buffer, 0, buffer.Length);
                    if (read <= 0)
                        return ms.ToArray();
                    ms.Write(buffer, 0, read);
                }
            }
        }
        public List<MyContent> MyContents { get; set; }
        public bool Success
        {
            get;
            private set;
        }
        public string ContentType
        {
            get;
            private set;
        }
        public string Filename
        {
            get;
            private set;
        }
        public byte[] FileContents
        {
            get;
            private set;
        }
    }
public class MyContent
    {
        public byte[] Data { get; set; }
        public string PropertyName { get; set; }
        public string StringData { get; set; }
    }

我确实从这里的得到了multipartParser

答案来源于我以前所做的。该服务可能如下所示：

[ServiceContract]
public class DocumentService
{
    [OperationContract]
    [WebTemplate("{name}"]
    public Document Create(Stream stream, string name)
    {
        var id = Guid.NewGuid().ToString("N");
        using(FileStream outputStream = File.Create(Path.Combine("c:''temp''", id)))
        {
            stream.CopyTo(outputStream);
        }
        Document document = new Document(); 
        document.Name = name;
        document.Id = id;
        // Save document to database
        // Set headers 
        return document;
    }
}

其中文档可能如下所示：

[DataContract]
public class Document
{
    [DataMember]
    public string Id
    {
       get;set;
    }
    [DataMember]
    public string Name
    {
       get;set;
    }
    /* other fields */
}

要将文件上载到服务（假设它位于http://api.example.com/documents/)，您可以执行以下操作：

string name = "mydocument.doc";
var request = WebRequest.Create ("http://api.example.com/documents/" + name);
request.ContentType = "application/octet-stream";
request.Method = "POST";
using(var stream = request.GetRequestStream())
{
    using(var inputStream = File.OpenRead("c:''mydocument.doc"))
    {
        inputStream.CopyTo(stream);
    }
}
using(var response = (HttpWebResponse)request.GetResponse())
{
    // process the response, if needed
}

如果您所做的只是发送一个流，那么就不需要发送多部分流。重要的是，任何参数（如名称）都应该是UriTemplate的一部分。