常用 Http 的请求方法

第一次用markdown写博客，体验下

因为常用Http的几种请求方式，总结一下。

1.封装两个Http的最常用方法，叫做HttpHelper类。

HttpPost:

    public static string HttpPost(string Url, string postDataStr)
    {
        HttpWebRequest request = (HttpWebRequest)WebRequest.Create(Url);
        request.Method = "POST";
        request.ContentType = "application/x-www-form-urlencoded";
        request.ContentLength = postDataStr.Length;

        StreamWriter writer = new StreamWriter(request.GetRequestStream(), Encoding.ASCII);
        writer.Write(postDataStr);
        writer.Flush();
        HttpWebResponse response = (HttpWebResponse)request.GetResponse();
        string encoding = response.ContentEncoding;

        if (encoding == null || encoding.Length < 1)
        {
            encoding = "UTF-8"; //默认编码
        }
        StreamReader reader = new StreamReader(response.GetResponseStream(), Encoding.GetEncoding(encoding));
        string retString = reader.ReadToEnd();
        return retString;
    }

HttpGet:

    public static string HttpGet(string Url)
    {
        HttpWebRequest request = (HttpWebRequest)WebRequest.Create(Url);
        request.Method = "GET";
        request.ContentType = "text/html;charset=UTF-8";

        HttpWebResponse response = (HttpWebResponse)request.GetResponse();
        Stream myResponseStream = response.GetResponseStream();
        StreamReader myStreamReader = new StreamReader(myResponseStream, Encoding.UTF8);
        string retString = myStreamReader.ReadToEnd();
        myStreamReader.Close();
        myResponseStream.Close();

        return retString;
    }

WebClientde中Post和Get:

	//Post
	using (var client = new WebClient())
	{
	    client.Headers[HttpRequestHeader.ContentType] = "application/json";
	    client.Encoding = Encoding.UTF8;
	    result = client.UploadString(postUrl, "POST", postData);
	}
	//Get
	var wc = new WebClient();
	var jsonResult = wc.DownloadString(Url);

封装好Http的方法，直接传入Url和postData即可，不必每次创建request对象。

更新：the remote server returned an error (401) unauthorized

    var req = (HttpWebRequest)WebRequest.Create(tgtUrl);
    req.UseDefaultCredentials = true;
    req.PreAuthenticate = true;
    req.Credentials = CredentialCache.DefaultCredentials;
    var response = req.GetResponse();
    var stream = req.GetRequestStream();

    var wc = new WebClient();
    //Set default credential, avoid unauthorize error
    wc.Credentials = CredentialCache.DefaultCredentials;
    wc.UseDefaultCredentials = true;