添加后台图片前台调用的图床接口备用，修复测试出现的问题

kazelee

2025-07-08 9f18954857e9c4c691fc2c8e83d7728abdc18f74

 util/HttpHelper.cs

@@ -103,6 +103,40 @@
            }
        }
        
        public string GetNew(string url, string contentType = null) {
            HttpWebRequest request = (HttpWebRequest)WebRequest.Create(url);
            request.Method = "GET";

            // 只有指定了contentType时才设置
            if (!string.IsNullOrEmpty(contentType)) {
                request.ContentType = contentType;
            }

            try {
                using (HttpWebResponse response = (HttpWebResponse)request.GetResponse())
                using (Stream stream = response.GetResponseStream())
                using (StreamReader reader = new StreamReader(stream)) {
                    return reader.ReadToEnd();
                }
            }
            catch (WebException ex) when (ex.Response is HttpWebResponse response) {
                // 记录详细的错误信息
                LogHelper.Info($"GET请求失败。状态码: {response.StatusCode}, URL: {url}", "API");

                // 读取错误响应内容
                using (Stream stream = response.GetResponseStream())
                using (StreamReader reader = new StreamReader(stream)) {
                    string errorResponse = reader.ReadToEnd();
                    LogHelper.Info($"错误响应内容: {errorResponse}", "API");
                }
                return string.Empty;
            }
            catch (Exception ex) {
                LogHelper.Info($"GET请求失败。URL: {url}, 错误: {ex.Message}", "API");
                return string.Empty;
            }
        }

        public string Post(string url, string postData, string contentType = "application/json", string sessionId = "") {
            Console.WriteLine(url);
            WebRequest request = WebRequest.Create(url);