C# Task.WhenAll

.C# Task.WhenAll

有时候我们需要同时执行一些操作，然后把这些操作的结果进行汇总，以达到用异步处理降低操作耗时的效果，此时我们会考虑使用Task，而Task.WhenAll则排上了用场。

 

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async void TestTaskWhenAll()        {            var total =10;            Task<string>[] tasks = new Task<string>[total];            for (int i = 0; i < total; i++)            {                tasks[i] =  Convert("test "+ i );            }            await Task.WhenAll(tasks);            foreach (var task in tasks)            {                Debug.WriteLine("task.Id =" + task.Id + "  task.Status=" + task.Status + " result:"+ task.Result);              }                return;        }   Random rnd = new Random();        async Task Convert(string str)        {              await  Task.Delay(rnd.Next(1000,6000));            Debug.Print(str+" OK");            return "task " + str;         }

　　

 结果：

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test 5 OK test 7 OK test 9 OK test 4 OK test 2 OK test 8 OK test 1 OK test 6 OK test 10 OK test 0 OK test 3 OK task.Id =4894  task.Status=RanToCompletion result:task C:\Users\Administrator\source\repos\MSTextSpeech\MSTextSpeech\bin\x86\Debug\net48\temp-637835462530097716 task.Id =4896  task.Status=RanToCompletion result:task C:\Users\Administrator\source\repos\MSTextSpeech\MSTextSpeech\bin\x86\Debug\net48\temp-637835462515158794 task.Id =4898  task.Status=RanToCompletion result:task C:\Users\Administrator\source\repos\MSTextSpeech\MSTextSpeech\bin\x86\Debug\net48\temp-637835462508434632 task.Id =4900  task.Status=RanToCompletion result:task C:\Users\Administrator\source\repos\MSTextSpeech\MSTextSpeech\bin\x86\Debug\net48\temp-637835462530342270 task.Id =4902  task.Status=RanToCompletion result:task C:\Users\Administrator\source\repos\MSTextSpeech\MSTextSpeech\bin\x86\Debug\net48\temp-637835462508404465 task.Id =4904  task.Status=RanToCompletion result:task C:\Users\Administrator\source\repos\MSTextSpeech\MSTextSpeech\bin\x86\Debug\net48\temp-637835462503610679 task.Id =4906  task.Status=RanToCompletion result:task C:\Users\Administrator\source\repos\MSTextSpeech\MSTextSpeech\bin\x86\Debug\net48\temp-637835462518147200 task.Id =4908  task.Status=RanToCompletion result:task C:\Users\Administrator\source\repos\MSTextSpeech\MSTextSpeech\bin\x86\Debug\net48\temp-637835462504196737 task.Id =4910  task.Status=RanToCompletion result:task C:\Users\Administrator\source\repos\MSTextSpeech\MSTextSpeech\bin\x86\Debug\net48\temp-637835462510625275 task.Id =4912  task.Status=RanToCompletion result:task C:\Users\Administrator\source\repos\MSTextSpeech\MSTextSpeech\bin\x86\Debug\net48\temp-637835462505016507 task.Id =4914  task.Status=RanToCompletion result:task C:\Users\Administrator\source\repos\MSTextSpeech\MSTextSpeech\bin\x86\Debug\net48\temp-637835462526342482