c#之如何在 C# 中向 Web 服务并行发出多个请求

我需要如下调用 3 个 WCF 服务，

var client = new WebClient(); 
    client.Headers[HttpRequestHeader.ContentType] = "application/json"; 
    var resultJson1 = client.UploadString("http://localhost:45868/Product/GetAvailableProductsByContact", 
                                         jsonser1); 
var resultJson2= client.UploadString("http://localhost:45868/Product/GetMemberProductsByContact", 
                                         jsonser2); 
 
var resultJson3= client.UploadString("http://localhost:45868/Product/GetCoachProductsByContact", 
                                         jsonser3); 

这需要花费大量时间来获取结果并显示在页面上。谁能帮助我如何并行执行它们？

请您参考如下方法:

您可以使用 task parallelism library :

Task<string>[] taskArray = new Task<string>[] 
    { 
        Task.Factory.StartNew(() => { 
            var client = new WebClient(); 
            client.Headers[HttpRequestHeader.ContentType] = "application/json"; 
            var json = client.UploadString("http://localhost:45868/Product/GetAvailableProductsByContact", 
                                     jsonser1); 
            return json; 
        }), 
        Task.Factory.StartNew(() => { 
            var client = new WebClient(); 
            client.Headers[HttpRequestHeader.ContentType] = "application/json"; 
            var json = client.UploadString("http://localhost:45868/Product/GetMemberProductsByContact", 
                                     jsonser2); 
            return json; 
        }), 
        Task.Factory.StartNew(() => { 
            var client = new WebClient(); 
            client.Headers[HttpRequestHeader.ContentType] = "application/json"; 
            var json = client.UploadString("http://localhost:45868/Product/GetCoachProductsByContact", 
                                     jsonser3); 
            return json; 
        }), 
    }; 
 
// the request for .Result is blocking and waits until each task 
// is completed before continuing; however, they should also all 
// run in parallel instead of sequentially. 
var resultJson1 = taskArray[0].Result; 
var resultJson2 = taskArray[1].Result; 
var resultJson3 = taskArray[2].Result; 

或者，由于您的请求都非常相似，仅 url 和上传字符串不同，您可以使用 LINQ AsParallel 数组处理:

var requests = new [] { 
    new { Url = "http://localhost:45868/Product/GetAvailableProductsByContact", Input = jsonser1 }, 
    new { Url = "http://localhost:45868/Product/GetMemberProductsByContact", Input = jsonser2 }, 
    new { Url = "http://localhost:45868/Product/GetCoachProductsByContact", Input = jsonser3 }, 
}; 
var result = requests.AsParallel().Select(req => { 
    var client = new WebClient(); 
    client.Headers[HttpRequestHeader.ContentType] = "application/json"; 
    var json = client.UploadString(req.Url, req.Input); 
    return json; 
}).ToArray(); 
 
// when above code has finished running, all tasks are completed 
var resultJson1 = result[0]; 
var resultJson2 = result[1]; 
var resultJson3 = result[2];