以下是一个使用C#发送带参数的POST请求的示例:
```csharp
using System;
using System.Net;
using System.IO;
using System.Text;
class Program
{
static void Main(string[] args)
{
string url = "http://example.com/api";
string postData = "param1=value1¶m2=value2";
byte[] byteArray = Encoding.UTF8.GetBytes(postData);
HttpWebRequest request = (HttpWebRequest)WebRequest.Create(url);
request.Method = "POST";
request.ContentType = "application/x-www-form-urlencoded";
request.ContentLength = byteArray.Length;
using (Stream stream = request.GetRequestStream())
{
stream.Write(byteArray, 0, byteArray.Length);
}
using (WebResponse response = request.GetResponse())
{
using (Stream stream = response.GetResponseStream())
{
StreamReader reader = new StreamReader(stream, Encoding.UTF8);
Console.WriteLine(reader.ReadToEnd());
}
}
}
}
```
在此示例中,我们首先定义了要发送POST请求的URL和要发送的数据。然后,我们将数据编码为字节数组,并创建一个HttpWebRequest对象来表示请求。我们设置请求方法为“POST”,内容类型为“application/x-www-form-urlencoded”,并设置ContentLength属性以指定请求正文的长度。
接下来,我们使用GetRequestStream()方法获取请求流,并将数据写入该流中。最后,我们使用GetResponse()方法获取响应,并从响应流中读取响应数据。