Question

我想从本地服务器下载字符串。准确地说来自ESP8266的wifi模块。我在那里发布一个纯粹的字符串，如“TEST”。我正在尝试

using (WebClient client = new WebClient())
{
    string s = client.DownloadString("http://192.168.0.13");
    MessageBox.Show(s);
}

但Exception抛出：

     System.Net.WebException: The server committed a protocol violation. section=ResponseStatusLine
   w System.Net.WebClient.DownloadDataInternal(Uri address, WebRequest& request)
   w System.Net.WebClient.DownloadString(Uri address)
   w System.Net.WebClient.DownloadString(String address)
   w logi.Logowanie.readEsp_Click(Object sender, EventArgs e) w d:\Projects Visual Studio\Projects\logi\logi\Logowanie.cs:line 81

我也尝试在html中构建字符串，所以它看起来像：

   string pagestr="<html><head><title>TEST</title></head><body<h2>Testing</h2></body></html>";

但错误是一样的。

对不起，我是这个新手......

Answer 1

这不是最安全或更明智的解决方案，但是如果你想摆脱困境，你可以将它添加到你的.config文件（在你的.NET项目上）以避免现在的问题：

<system.net>
    <settings>
        <httpWebRequest useUnsafeHeaderParsing="true" />
    </settings>
</system.net>

但是您应该知道WebServer代码存在一些问题。也许发布服务器代码可能会帮助您解决问题。

你也可以尝试这样做：

HttpWebRequest myHttpWebRequest1 =
(HttpWebRequest)WebRequest.Create("http://192.168.0.13");
myHttpWebRequest1.KeepAlive=false;
HttpWebResponse myHttpWebResponse1 = 
        (HttpWebResponse)myHttpWebRequest1.GetResponse();

这样您就可以将KeepAlive属性设置为false。

Answer 2

＆＃13;

using System.IO;
using System.Net;
using System.Net.Http;

namespace WindowsFormsApplication8
{
    public partial class Form1 : Form
    {
        public Form1()
        {
            InitializeComponent();

            //setLabel();

            Timer timer = new Timer();
            timer.Interval = (100); // 10 secs
            timer.Tick += new EventHandler(timer_Tick);
            timer.Start();
        }

        private void timer_Tick(object sender, EventArgs e)
        {

            setLabel();
        }

        public void setLabel()
        {

            var url = "http://192.168.0.105/data.txt";

            var textFromFile = (new WebClient()).DownloadString(url);
            label1.Text = textFromFile + "Kg";

        }

       
    }
}

＆＃13;

using System.IO;
using System.Net;
using System.Net.Http;

namespace WindowsFormsApplication8
{
    public partial class Form1 : Form
    {
        public Form1()
        {
            InitializeComponent();

            //setLabel();

            Timer timer = new Timer();
            timer.Interval = (100); // 10 secs
            timer.Tick += new EventHandler(timer_Tick);
            timer.Start();
        }

        private void timer_Tick(object sender, EventArgs e)
        {

            setLabel();
        }

        public void setLabel()
        {

            var url = "http://192.168.0.105/data.txt";

            var textFromFile = (new WebClient()).DownloadString(url);
            label1.Text = textFromFile + "Kg";

        }

       
    }
}

＆＃13;

如何从服务器（ESP8266 WiFi模块）下载数据？

2 个答案: