How to check for async processes running

Question

Does anyone know any way, to check if any process Async is being executed?

For example, I would like to do a check, when the user closes the system, and not let close all processes Async be completed.

async public void EvokeMetodo(string contrato, int item,  bool editar)
    {
        //retorna um datatable contendo o iten que foi salvo ou editado
        DataTable Ret_Contrato = await Ret_Datatable(contrato, item);
        int verificador = 0;
        //insert
        if (!editar)
        {
            //retorna o numero de linhas afetadas, ou seja, o numero de insert feitos
            verificador = await Insert_ContratoItens(Ret_Contrato);

            if(verificador > 0)
            {
                atualiza_ContratoWeb(contrato, item);
            }
        }
        else//update
        {
            verificador = await Update_ContratoItens(Ret_Contrato);

            if (verificador > 0)
            {
                atualiza_ContratoWeb(contrato, item);
            }
        }
    }

Answer 1

The right and most effective way to verify this is through Tasks.

1. Turn your method into a task

Let’s turn your method into one Task so that it is possible to use the Directive await, if you want to wait for your method to execute to proceed.

private async Task EvokeMetodo(string contrato, int item,  bool editar)
{
    //retorna um datatable contendo o iten que foi salvo ou editado
    DataTable Ret_Contrato = await Ret_Datatable(contrato, item);
    int verificador = 0;
    //insert
    if (!editar)
    {
        //retorna o numero de linhas afetadas, ou seja, o numero de insert feitos
        verificador = await Insert_ContratoItens(Ret_Contrato);

        if(verificador > 0)
        {
            atualiza_ContratoWeb(contrato, item);
        }
    }
    else//update
    {
        verificador = await Update_ContratoItens(Ret_Contrato);

        if (verificador > 0)
        {
            atualiza_ContratoWeb(contrato, item);
        }
    }
}

Cannot be used await in void, so we created a Task. Note that this Task it’s not returning anything, it’s like a void roughly speaking, as it will only perform. If you want the method to return something, just change Task for Task<int> and she’ll need you to return a int, for example.

2. Execute your Task

Here we will execute your Task (method) and store the execution in a variable Task, so you can check your status later. In this example, I put your method execution in an event Click a button. Note that the Click button has the directive async.

private async void button1_Click(object sender, EventArgs e)
{
   Task task = Task.Run(async () =>
   {
       await EvokeMetodo();
   });
}

How I used await within the Task.Run to wait for the execution of the method EvokeMetodo, it is necessary to use a lambda expression with the directive async() to "invoke" your method and inform Task.Run that you want to wait for the execution of the method that it will execute. More specifically in this part:

Task.Run(async () =>
{
   await EvokeMetodo();
});

3. Verifying the status of your Task

If noticed earlier, we store the execution (return) of the method Task.Run in a variable of type Task calling for task. Through this, it is possible to check the status of the Task.

if(task.IsCompleted)
{
   // Faça alguma coisa
}

Besides task.IsCompleted we also have task.IsCanceled and task.IsFaulted.

Answer 2

I think this solves, create a Global variable named asyncRodando and in its async code put

asyncRodando = true;
// CÓDIGO ASYNC AQUI
asyncRodando = false;

And at closing time do something like.

{
if(asyncRodando)
return;

fecharPrograma();

}