Question

我正在尝试使用异步和等待，我的问题是它不会等待后台进程完成。也许你想知道我为什么不同步运行应用程序？我正在尽快完成我的任务的一部分，其余的可以等待，如本例所示。谢谢你的帮助！ =）

class Program
{
    static void Main(string[] args)
    {
        Run();
        //Problem or Maybe Not? Needs this 
        //So that my application won't close immediately
        Console.ReadLine();
    }

    private async static void Run()
    {
        Task<bool> TBool = ProcessRecords();

        if (await TBool)
        {
            //Problem #1 This Line Doesn't Show
            Console.WriteLine("End of Code");
            //SHould be safe to close the application by Now
            //But goes through here not waiting for the return
            //of the last process.

            Environment.Exit(0);

            //My temporary solution is to indicate a Task.Delay(80000)
            //to make sure that all the logging in the background
            //are all done. I dont know if there is a function that shows
            //that there are task running on the background or any 
            //other workaroung will help. =) thanks
        }

    }

    private async static Task<bool> ProcessRecords()
    {
        Task newTask = null;
        //Loop through all the records and send
        //all the records to MQ ASAP
        for (int x = 0; x < 10; x++)
        {
            //I wont wait for this Task so
            //I can send the next record
            newTask = SendToMQ(x);
        }
        //I only need to wait for the last Task to
        //indicate that I can exit the system
        //as soon as it finish
        //Problem #2 The Console.WriteLine doesnt show the last record.
        await newTask;
        return true;
    }

    private async static Task SendToMQ(int count)
    {
        //actual sending of message (Important)
        await Task.Delay(1000);
        //Process of Logging Connect to DB etc, (Not so Important, but takes most of the time)
        await LoggingRecord();
        Console.Clear();
        Console.WriteLine("Done Processing  " + count.ToString() + " records");
    }

    //Logging of each record
    private async static Task LoggingRecord()
    {
        await Task.Delay(5000);
        //Problem #3 This Line Doesn't Show
        Console.WriteLine("Last Log Finished");
    }
}

Answer 1

你应该尽可能使用等待：

await Run();

但是，在这种情况下你不能，所以你必须使用Wait

static void Main(string[] args)
{
    Run().Wait();

    //Problem or Maybe Not? Needs this 
    //So that my application won't close immediately
    //Console.ReadLine();
}

// note the return type is Task
private async static Task Run()
{
...
}

在ProcessRecords（）中你有以下几行 - 我不太清楚你的意思，所以我没有解决它：

//Problem #2 The Console.WriteLine doesnt show the last record.

以上打印

Done Processing  9 records
End of Code

使用Async时如何知道Task或Void方法是否仍在运行

1 个答案: