public static void TestTaskFunctionWithoutAwait1()
{
TaskDemo taskDemo = new TaskDemo();
Task[] tasks = new Task[10];
for (int i = 0; i < 10; i++)
{
tasks[i] = taskDemo.AsyncFunction(i);
}
for (int i = 0; i < 10; i++)
{
// If in a async function, you can use this:
//await tasks[i];
tasks[i].Wait();
}
Console.WriteLine(10);
}
// The several Test1 functions is running in serial(They have the same Current Thread ID)
// and several Test2 functions is running in parallel(They have different Current Thread ID).
public static void TestTaskFunctionWithoutAwait2()
{
Task[] tasks = new Task[10];
TaskDemo p = new TaskDemo();
tasks[0] = p.Test1();
tasks[1] = p.Test2();
tasks[2] = p.Test1();
tasks[3] = p.Test2();
tasks[4] = p.Test1();
tasks[5] = p.Test2();
tasks[6] = p.Test1();
tasks[7] = p.Test2();
tasks[8] = p.Test1();
tasks[9] = p.Test3();
for (int i = 0; i < 10; i++)
{
tasks[i].Wait();
}
}
public static void NewTaskDemo()
{
TaskDemo instance = new TaskDemo();
Task task = instance.NewTaskAsyncFunction();
Console.WriteLine("Main therad start...");
task.Wait(); // Start may not be called on a promise-style task.
Console.WriteLine("Main therad end...");
/*Output:
* Main therad start...
* Task start...
* Task end...
* Main therad end...
*/
Console.WriteLine("====================");
Task task2 = new Task(async() =>
{
Console.WriteLine("Task start...");
await Task.Delay(TimeSpan.FromSeconds(2));
Console.WriteLine("Task end...");
});
Console.WriteLine("Main therad start...");
// Make sure why it does not work like we think.
// We can see the difference through running the build result in CMD.
task2.Start();
task2.Wait();
Console.WriteLine("Main therad end...");
/*Output:
* Main therad start...
* Task start...
* Main therad end...
* Task end...
*/
Console.WriteLine("====================");
// This is what we want
Task task3 = Task.Run(async() =>
{
Console.WriteLine("Task start...");
await Task.Delay(TimeSpan.FromSeconds(2));
Console.WriteLine("Task end...");
});
Console.WriteLine("Main therad start...");
// Exception:
// System.InvalidOperationException
// Message=Start may not be called on a promise-style task.
//task3.Start();
task3.Wait();
Console.WriteLine("Main therad end...");
/*Output:
* Main therad start...
* Task start...
* Task end...
* Main therad end...
*/
Console.WriteLine("====================");
// This is what we want.
Console.WriteLine("Main therad start...");
Func <Task> task4 = async() =>
{
Console.WriteLine("Task start...");
await Task.Delay(TimeSpan.FromSeconds(2));
Console.WriteLine("Task end...");
};
task4().Wait();
Console.WriteLine("Main therad end...");
/*Output:
* Main therad start...
* Task start...
* Task end...
* Main therad end...
*/
}
