1.WebRequest方式

引用dll

using System.IO;
using System.Net;
using System.Threading.Tasks;

//Post
public static string HttpPost(string url, string body)
{
	Encoding encoding = Encoding.UTF8;
	HttpWebRequest request = (HttpWebRequest)WebRequest.Create(url);
	request.Method = "POST";
	request.Accept = "text/html, application/xhtml+xml, */*";
	request.ContentType = "application/json";


	byte[] buffer = encoding.GetBytes(body);
	request.ContentLength = buffer.Length;
	request.GetRequestStream().Write(buffer, 0, buffer.Length);
	HttpWebResponse response = (HttpWebResponse)request.GetResponse();
	using (StreamReader reader = new StreamReader(response.GetResponseStream(), Encoding.UTF8))
	{
		return reader.ReadToEnd();
	}
}


//GET
public static string HttpGet(string url)
{
	Encoding encoding = Encoding.UTF8;
	HttpWebRequest request = (HttpWebRequest)WebRequest.Create(url);
	request.Method = "GET";
	request.Accept = "text/html, application/xhtml+xml, */*";
	request.ContentType = "application/json";


	HttpWebResponse response = (HttpWebResponse)request.GetResponse();
	using (StreamReader reader = new StreamReader(response.GetResponseStream(), Encoding.UTF8))
	{
		return reader.ReadToEnd();
	}
}

2.HttpClient 方式

static HttpClient client = new HttpClient();


//根据 ID 获取产品
static async Task<Uri> CreateProductAsync(Product product)
{
	HttpResponseMessage response = await client.PostAsJsonAsync(
		"api/products", product);
	response.EnsureSuccessStatusCode();


	// return URI of the created resource.
	return response.Headers.Location;
}


//创建新产品
static async Task<Product> GetProductAsync(string path)
{
	Product product = null;
	HttpResponseMessage response = await client.GetAsync(path);
	if (response.IsSuccessStatusCode)
	{
		product = await response.Content.ReadAsAsync<Product>();
	}
	return product;
}


//更新产品
static async Task<Product> UpdateProductAsync(Product product)
{
	HttpResponseMessage response = await client.PutAsJsonAsync(
		#34;api/products/{product.Id}", product);
	response.EnsureSuccessStatusCode();


	// Deserialize the updated product from the response body.
	product = await response.Content.ReadAsAsync<Product>();
	return product;
}


//删除产品
static async Task<HttpStatusCode> DeleteProductAsync(string id)
{
	HttpResponseMessage response = await client.DeleteAsync(
		#34;api/products/{id}");
	return response.StatusCode;
}

HttpClient 异步调用

static async Task RunAsync()
{
    client.BaseAddress = new Uri("http://localhost:64195/");
    client.DefaultRequestHeaders.Accept.Clear();
    client.DefaultRequestHeaders.Accept.Add(
        new MediaTypeWithQualityHeaderValue("application/json"));


    try
    {
        Product product = new Product
        {
            Name = "Gizmo",
            Price = 100,
            Category = "Widgets"
        };


        var url = await CreateProductAsync(product);
        Console.WriteLine(#34;Created at {url}");


        // Get the product
        product = await GetProductAsync(url.PathAndQuery);
        ShowProduct(product);


        // Update the product
        Console.WriteLine("Updating price...");
        product.Price = 80;
        await UpdateProductAsync(product);


        // Get the updated product
        product = await GetProductAsync(url.PathAndQuery);
        ShowProduct(product);


        // Delete the product
        var statusCode = await DeleteProductAsync(product.Id);
        Console.WriteLine(#34;Deleted (HTTP Status = {(int)statusCode})");


    }
    catch (Exception e)
    {
        Console.WriteLine(e.Message);
    }


    Console.ReadLine();
}

• C#实现西门子S7-1200、200 SMART PLC之间通信
• C#连接FTP实现文件上传下载
• C#实现MQTT通讯
• C#实现串口通讯
• C#实现WebSocket服务和通讯
• C#实现UDP通讯
• C#实现TCP通讯