WebClient Headers

使用WebClient类进行Post操作时遇到错误：This header must be modified using the appropriate property.

字面意思就是要求使用恰当的属性，那么WebClient的Header都有哪些可用的属性呢？

以下是我从网上搜索到的：

使用时wc.Headers.Add("ContentType","application/x-www-form-urlencoded");

 

// Summary:        //     The Cache-Control header, which specifies directives that must be obeyed        //     by all cache control mechanisms along the request/response chain.        CacheControl = 0,        //        // Summary:        //     The Connection header, which specifies options that are desired for a particular        //     connection.        Connection = 1,        //        // Summary:        //     The Date header, which specifies the date and time at which the request originated.        Date = 2,        //        // Summary:        //     The Keep-Alive header, which specifies a parameter used into order to maintain        //     a persistent connection.        KeepAlive = 3,        //        // Summary:        //     The Pragma header, which specifies implementation-specific directives that        //     might apply to any agent along the request/response chain.        Pragma = 4,        //        // Summary:        //     The Trailer header, which specifies the header fields present in the trailer        //     of a message encoded with chunked transfer-coding.        Trailer = 5,        //        // Summary:        //     The Transfer-Encoding header, which specifies what (if any) type of transformation        //     that has been applied to the message body.        TransferEncoding = 6,        //        // Summary:        //     The Upgrade header, which specifies additional communications protocols that        //     the client supports.        Upgrade = 7,        //        // Summary:        //     The Via header, which specifies intermediate protocols to be used by gateway        //     and proxy agents.        Via = 8,        //        // Summary:        //     The Warning header, which specifies additional information about that status        //     or transformation of a message that might not be reflected in the message.        Warning = 9,        //        // Summary:        //     The Allow header, which specifies the set of HTTP methods supported.        Allow = 10,        //        // Summary: // The Content-Length header, which specifies the length, in bytes, of the accompanying        //     body data.        ContentLength = 11,        //        // Summary:        //     The Content-Type header, which specifies the MIME type of the accompanying        //     body data.        ContentType = 12,        //        // Summary:        //     The Content-Encoding header, which specifies the encodings that have been        //     applied to the accompanying body data.        ContentEncoding = 13,        //        // Summary:        //     The Content-Langauge header, which specifies the natural language(s) of the        //     accompanying body data.        ContentLanguage = 14,        //        // Summary:        //     The Content-Location header, which specifies a URI from which the accompanying        //     body may be obtained.        ContentLocation = 15,        //        // Summary:        //     The Content-MD5 header, which specifies the MD5 digest of the accompanying        //     body data, for the purpose of providing an end-to-end message integrity check.        ContentMd5 = 16,        //        // Summary:        //     The Content-Range header, which specifies where in the full body the accompanying        //     partial body data should be applied.        ContentRange = 17,        //        // Summary:        //     The Expires header, which specifies the date and time after which the accompanying        //     body data should be considered stale.        Expires = 18,        //        // Summary:        //     The Last-Modified header, which specifies the date and time at which the        //     accompanying body data was last modified.        LastModified = 19,        //        // Summary:        //     The Accept header, which specifies the MIME types that are acceptable for        //     the response.        Accept = 20,        //        // Summary:        //     The Accept-Charset header, which specifies the character sets that are acceptable        //     for the response.        AcceptCharset = 21,        //        // Summary:        //     The Accept-Encoding header, which specifies the content encodings that are        //     acceptable for the response.        AcceptEncoding = 22,        //        // Summary:        //     The Accept-Langauge header, which specifies that natural languages that are        //     preferred for the response.        AcceptLanguage = 23,        //        // Summary:        //     The Authorization header, which specifies the credentials that the client        //     presents in order to authenticate itself to the server.        Authorization = 24,        //        // Summary:        //     The Cookie header, which specifies cookie data presented to the server.        Cookie = 25,        //        // Summary:        //     The Expect header, which specifies particular server behaviors that are required        //     by the client.        Expect = 26,        //        // Summary:        //     The From header, which specifies an Internet E-mail address for the human        //     user who controls the requesting user agent.        From = 27,        //        // Summary:        //     The Host header, which specifies the host name and port number of the resource        //     being requested.        Host = 28,        //        // Summary:        //     The If-Match header, which specifies that the requested operation should        //     be performed only if the client's cached copy of the indicated resource is        //     current.        IfMatch = 29,        //        // Summary:        //     The If-Modified-Since header, which specifies that the requested operation        //     should be performed only if the requested resource has been modified since        //     the indicated data and time.        IfModifiedSince = 30,        //        // Summary:        //     The If-None-Match header, which specifies that the requested operation should        //     be performed only if none of client's cached copies of the indicated resources        //     are current.        IfNoneMatch = 31,        //        // Summary:        //     The If-Range header, which specifies that only the specified range of the        //     requested resource should be sent, if the client's cached copy is current.        IfRange = 32,        //        // Summary:        //     The If-Unmodified-Since header, which specifies that the requested operation        //     should be performed only if the requested resource has not been modified        //     since the indicated date and time.        IfUnmodifiedSince = 33,        //        // Summary:        //     The Max-Forwards header, which specifies an integer indicating the remaining        //     number of times that this request may be forwarded.        MaxForwards = 34,        //        // Summary:        //     The Proxy-Authorization header, which specifies the credentials that the        //     client presents in order to authenticate itself to a proxy.        ProxyAuthorization = 35,        //        // Summary:        //     The Referer header, which specifies the URI of the resource from which the        //     request URI was obtained.        Referer = 36,        //        // Summary:        //     The Range header, which specifies the the sub-range(s) of the response that        //     the client requests be returned in lieu of the entire response.        Range = 37,        //        // Summary:        //     The TE header, which specifies the transfer encodings that are acceptable        //     for the response.        Te = 38,        //        // Summary:        //     The Translate header, a Microsoft extension to the HTTP specification used        //     in conjunction with WebDAV functionality.        Translate = 39,        //        // Summary:        //     The User-Agent header, which specifies information about the client agent.        UserAgent = 40,