HttpClient
是C#中用于发送HTTP请求的类,基于HttpClient的异步模型,可以实现GET、POST请求,处理响应数据,上传和下载文件,以及设置Authorization、cookie等。
using (HttpClient client = new HttpClient())
{
HttpResponseMessage response = await client.GetAsync("https://example.com/api/resource");
// 处理响应
}
using (HttpClient client = new HttpClient())
{
var content = new StringContent("data to send", Encoding.UTF8, "application/json");
HttpResponseMessage response = await client.PostAsync("https://example.com/api/resource", content);
// 处理响应
}
using (HttpClient client = new HttpClient())
{
var content = new MultipartFormDataContent();
content.Add(new ByteArrayContent(File.ReadAllBytes("file.txt")), "file", "file.txt");
HttpResponseMessage response = await client.PostAsync("https://example.com/api/upload", content);
// 处理响应
}
using (HttpClient client = new HttpClient())
{
byte[] fileData = await client.GetByteArrayAsync("https://example.com/api/download");
File.WriteAllBytes("downloaded_file.txt", fileData);
}
using (HttpClient client = new HttpClient())
{
client.DefaultRequestHeaders.Authorization = new AuthenticationHeaderValue("Bearer", "your_access_token");
HttpResponseMessage response = await client.GetAsync("https://example.com/api/resource");
// 处理响应
}
using (HttpClient client = new HttpClient())
{
var cookieContainer = new CookieContainer();
var handler = new HttpClientHandler { CookieContainer = cookieContainer };
using (var httpClient = new HttpClient(handler))
{
HttpResponseMessage response = await client.GetAsync("https://example.com/api/resource");
// 处理响应
}
}
HttpClient
实例。GetAsync
方法发送GET请求。HttpResponseMessage
以获取响应数据。HttpClient
实例。StringContent
或FormUrlEncodedContent
作为请求内容。PostAsync
方法发送POST请求。HttpResponseMessage
以获取响应数据。HttpClient
实例。MultipartFormDataContent
,添加ByteArrayContent
作为文件内容。PostAsync
方法发送包含文件的请求。HttpResponseMessage
以获取响应数据。HttpClient
实例。GetByteArrayAsync
方法获取文件的字节数组。File.WriteAllBytes
保存文件。HttpClient
实例。DefaultRequestHeaders.Authorization
属性为AuthenticationHeaderValue
。HttpClient
实例。CookieContainer
和HttpClientHandler
实例。HttpClientHandler
中设置CookieContainer
。HttpClientHandler
的HttpClient
实例发送请求。// 示例代码请根据实际情况修改URL和文件路径
// 发送GET请求
using (HttpClient client = new HttpClient())
{
HttpResponseMessage response = await client.GetAsync("https://example.com/api/resource");
// 处理响应
}
// 发送POST请求
using (HttpClient client = new HttpClient())
{
var content = new StringContent("data to send", Encoding.UTF8, "application/json");
HttpResponseMessage response = await client.PostAsync("https://example.com/api/resource", content);
// 处理响应
}
// 上传文件
using (HttpClient client = new HttpClient())
{
var content = new MultipartFormDataContent();
content.Add(new ByteArrayContent(File.ReadAllBytes("file.txt")), "file", "file.txt");
HttpResponseMessage response = await client.PostAsync("https://example.com/api/upload", content);
// 处理响应
}
// 下载文件
using (HttpClient client = new HttpClient())
{
byte[] fileData = await client.GetByteArrayAsync("https://example.com/api/download");
File.WriteAllBytes("downloaded_file.txt", fileData);
}
// 设置Authorization
using (HttpClient client = new HttpClient())
{
client.DefaultRequestHeaders.Authorization = new AuthenticationHeaderValue("Bearer", "your_access_token");
HttpResponseMessage response = await client.GetAsync("https://example.com/api/resource");
// 处理响应
}
// 设置Cookie
using (HttpClient client = new HttpClient())
{
var cookieContainer = new CookieContainer();
var handler = new HttpClientHandler { CookieContainer = cookieContainer };
using (var httpClient = new HttpClient(handler))
{
HttpResponseMessage response = await client.GetAsync("https://example.com/api/resource");
// 处理响应
}
}
using
语句确保及时释放HttpClient
资源。通过HttpClient
,我们能够在C#中方便地进行HTTP请求操作,包括GET、POST请求、文件上传和下载,以及设置Authorization、cookie等。确保使用异步操作和适当的异常处理,能够保证请求的稳定性和性能。