C#中的Http访问总结
标签：网络连接 returns scom 连接服务器 method AC virt dwr pos
第一种是最基本的Http访问，这是同步调用，会有延迟和卡顿：
///
/// 向服务器发送Request
///
/// 字符串
/// 枚举类型的方法Get或者Post
/// Post时必须传值
/// 超时时间，单位秒
///
public static string Request(string url, MethodEnum method, string body = "", int timeoutSeconds = 15000)
{
if (!IsConnectedInternet())
return "网络连接错误，请稍后再试。";
try
{
GC.Collect();
HttpWebRequest request = (HttpWebRequest)WebRequest.Create(url);
request.Timeout = timeoutSeconds;
request.Method = method.ToString();
//如果是Post的话，则设置body
if (method == MethodEnum.POST)
{
request.ContentType = "application/json";
request.KeepAlive = false;
byte[] requestBody = Encoding.UTF8.GetBytes(body);
request.ContentLength = requestBody.Length;
Stream requestStream = request.GetRequestStream();
requestStream.Write(requestBody, 0, requestBody.Length);
}
return Response(request);
}
catch (Exception ex)
{
if (ex.InnerException != null)
return ex.InnerException.Message;
if (ex.Message.Contains("已取消一个任务"))
return "连接服务器超时，请重试";
if (ex.Message.Contains("404"))
return "连接服务器404，请重试";
return ex.Message;
}
}
///
/// 返回Response数据
///
///
///
private static string Response(HttpWebRequest request)
{
HttpWebResponse response = (HttpWebResponse)request.GetResponse();
string jsonRead = "";
if (response.StatusCode != HttpStatusCode.OK)
{
return response.StatusCode.ToString();
}
//接收过程
if (response.GetResponseStream() != null)
{
StreamReader myStreamReader = new StreamReader(response.GetResponseStream() ?? Stream.Null, Encoding.UTF8);
jsonRead = myStreamReader.ReadToEnd();
myStreamReader.Close();
}
response.Close();
request.Abort();
return jsonRead;
}
第二种是使用HttpClient来实现异步访问：
1 public static async void AsyncPost(string url, string body, Action callback, int timeoutSeconds = 10)
2 {
3 var requestResult = new RequestResult();
4 if (!IsConnectedInternet())
5 {
6 requestResult.Message = "网络连接错误，请稍后再试。";
7 callback?.Invoke(requestResult);
8 return;
9 }
10
11 try
12 {
13 using (var client = new HttpClient())
14 {
15 client.Timeout = new TimeSpan(0, 0, timeoutSeconds);
16 //byte[] requestBody = Encoding.UTF8.GetBytes(body);
17 HttpContent content = new StringContent(body);
18 content.Headers.ContentType = new MediaTypeHeaderValue("application/json");
19 var response = await client.PostAsync(url, content);
20 //确保HTTP成功状态值
21 response.EnsureSuccessStatusCode();
22 //await异步读取最后的JSON
23 await response.Content.ReadAsStringAsync().ContinueWith(t =>
24 {
25 if (t.IsCompleted)
26 {
27 requestResult.IsSuccess = true;
28 requestResult.Result = t.Result;
29 callback?.Invoke(requestResult);
30 }
31 });
32 }
33 }
34 catch (Exception e)
35 {
36 if (e.InnerException != null)
37 requestResult.Message = e.InnerException.Message;
38 else if (e.Message.Contains("已取消一个任务"))
39 requestResult.Message = "连接服务器超时，请重试";
40 else if (e.Message.Contains("404"))
41 requestResult.Message = "连接服务器404，请重试";
42 else
43 requestResult.Message = e.Message;
44 callback?.Invoke(requestResult);
45 }
46 }
47
48 public static async void AsyncGet(string url, Action callback, int timeoutSeconds = 10)
49 {
50 var requestResult = new RequestResult();
51 if (!IsConnectedInternet())
52 {
53 requestResult.Message = "网络连接错误，请稍后再试。";
54 callback?.Invoke(requestResult);
55 return;
56 }
57
58 try
59 {
60 using (var client = new HttpClient())
61 {
62 client.Timeout = new TimeSpan(0, 0, timeoutSeconds);
63 var response = await client.GetAsync(url);
64 //确保HTTP成功状态值
65 response.EnsureSuccessStatusCode();
66 //await异步读取最后的JSON
67 await response.Content.ReadAsStringAsync().ContinueWith(t =>
68 {
69 if (t.IsCompleted)
70 {
71 requestResult.IsSuccess = true;
72 requestResult.Result = t.Result;
73 callback?.Invoke(requestResult);
74 }
75 });
76 }
77 }
78 catch (Exception e)
79 {
80 if (e.InnerException != null)
81 requestResult.Message = e.InnerException.Message;
82 else if (e.Message.Contains("已取消一个任务"))
83 requestResult.Message = "连接服务器超时，请重试";
84 else if (e.Message.Contains("404"))
85 requestResult.Message = "连接服务器404，请重试";
86 else
87 requestResult.Message = e.Message;
88 callback?.Invoke(requestResult);
89 }
90 }
91
92 public static async void AsyncPut(string url, string body, Action callback, int timeoutSeconds = 10)
93 {
94 var requestResult = new RequestResult();
95 if (!IsConnectedInternet())
96 {
97 requestResult.Message = "网络连接错误，请稍后再试。";
98 callback?.Invoke(requestResult);
99 return;
100 }
101
102 try
103 {
104 using (var client = new HttpClient())
105 {
106 client.Timeout = new TimeSpan(0, 0, timeoutSeconds);
107 HttpContent content = new StringContent(body);
108 content.Headers.ContentType = new MediaTypeHeaderValue("application/json");
109 var response = await client.PutAsync(url, content);
110 //确保HTTP成功状态值
111 response.EnsureSuccessStatusCode();
112 //await异步读取最后的JSON
113 await response.Content.ReadAsStringAsync().ContinueWith(t =>
114 {
115 if (t.IsCompleted)
116 {
117 requestResult.IsSuccess = true;
118 requestResult.Result = t.Result;
119 callback?.Invoke(requestResult);
120 }
121 });
122 }
123 }
124 catch (Exception e)
125 {
126 if (e.InnerException != null)
127 requestResult.Message = e.InnerException.Message;
128 else if (e.Message.Contains("已取消一个任务"))
129 requestResult.Message = "连接服务器超时，请重试";
130 else if (e.Message.Contains("404"))
131 requestResult.Message = "连接服务器404，请重试";
132 else
133 requestResult.Message = e.Message;
134 callback?.Invoke(requestResult);
135 }
136 }
137
138 public static async void AsyncDelete(string url, Action callback, int timeoutSeconds = 10)
139 {
140 var requestResult = new RequestResult();
141 if (!IsConnectedInternet())
142 {
143 requestResult.Message = "网络连接错误，请稍后再试。";
144 callback?.Invoke(requestResult);
145 return;
146 }
147
148 try
149 {
150 using (var client = new HttpClient())
151 {
152 client.Timeout = new TimeSpan(0, 0, timeoutSeconds);
153 var response = await client.DeleteAsync(url);
154 //确保HTTP成功状态值
155 response.EnsureSuccessStatusCode();
156 //await异步读取最后的JSON
157 await response.Content.ReadAsStringAsync().ContinueWith(t =>
158 {
159 if (t.IsCompleted)
160 {
161 requestResult.IsSuccess = true;
162 requestResult.Result = t.Result;
163 callback?.Invoke(requestResult);
164 }
165 });
166 }
167 }
168 catch (Exception e)
169 {
170 if (e.InnerException != null)
171 requestResult.Message = e.InnerException.Message;
172 else if (e.Message.Contains("已取消一个任务"))
173 requestResult.Message = "连接服务器超时，请重试";
174 else if (e.Message.Contains("404"))
175 requestResult.Message = "连接服务器404，请重试";
176 else
177 requestResult.Message = e.Message;
178 callback?.Invoke(requestResult);
179 }
180 }
定义一个异步返回信息的类：
1 public class RequestResult : IDisposable
2 {
3 public bool IsSuccess { get; set; }
4
5 public string Result { get; set; }
6
7 public string Message { get; set; }
8
9 public RequestResult(bool isSuccess = false, string result = "", string message = "")
10 {
11 IsSuccess = isSuccess;
12 Result = result;
13 Message = message;
14 }
15
16 ~RequestResult()
17 {
18 Dispose();
19 }
20
21 public void Dispose()
22 {
23 Dispose(true);
24 GC.SuppressFinalize(this);//不需要再调用本对象的Finalize方法
25 }
26
27 protected virtual void Dispose(Boolean disposing)
28 {
29 if (disposing)
30 {
31 //--- 清理托管资源 ---//
32 }
33
34 //--- 清理非托管资源 ---//
35 }
36 }
附带一个检测网络连接状态的方法：
1 [DllImport("winInet.dll")]
2 private static extern bool InternetGetConnectedState(ref int dwFlag, int dwReserved);
3
4 ///
5 /// 用于检查网络是否可以连接互联网,true表示连接成功,false表示连接失败
6 ///
7 ///
8 private static bool IsConnectedInternet()
9 {
10 int description = 0;
11 return InternetGetConnectedState(ref description, 0);
12 }
C#中的Http访问总结
标签：网络连接 returns scom 连接服务器 method AC virt dwr pos
原文地址：https://www.cnblogs.com/lionwang/p/9089969.html
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