通过Web POST将带有特殊字符/符号的字符串发送到PHP服务

Question

I'm trying to send a long string through HTTP post using C# and the WebClient . This code works when the string does not contain any special characters/symbols, but fails when the string does:

        string stringtosend= File.ReadAllText("string.txt");

        using (WebClient webClient = new WebClient())
        {
            string address = myurl;
            byte[] postData = Encoding.UTF8.GetBytes("texto"= + stringtosend); 
            webClient.Headers[HttpRequestHeader.Accept] = "text/html, application/xhtml+xml, */*";
            webClient.Headers[HttpRequestHeader.AcceptLanguage] = "ru-RU";
            webClient.Headers[HttpRequestHeader.AcceptEncoding] = "gzip, deflate";
            webClient.Headers[HttpRequestHeader.ContentType] = "application/x-www-form-urlencoded";
            webClient.UploadData(address, postData);
        }

    }

The service the file is being sent to is implemented in PHP. The PHP code is as follows:

//GUARDAR EL LOG
if ($texto_post != "" && $id_post != "" && $tarea_post == "klog") {
    $fp = fopen("klog.txt", 'w');
    fwrite($fp, $texto_post);
    fclose($fp);
    die();

}

I tried to encode with Base64 but it does not work for strings that contains special characters/symbols. The following sample file is around 10kb and fails: https://www.sendspace.com/file/b3i4vl

When I send a larger file (around 20kb) with only "asdasdasd" repeated, it succeeds. What is causing the file with the special characters to fail?

Answer 1

There is a limitation on what you can upload by default, see this post:

Is there an upload limit when using Web Client in C#?

You can change it in the web.config under the <system.web> section.

Answer 2

You are not telling us the server where the services that receive this data is on.

IIS has a limit on how large the data can be. Above that limit it will reject. Apache probably has some limits too.

If it's IIS then change the web.config setting for the <requestLimits> . The attribute you are looking for is maxAllowedContentLength

You can also do this from the IIS console. More on this and limits here .