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J. Rodríguez
Asked: 2020-03-22 05:50:34 +0800 CST 2020-03-22 05:50:34 +0800 CST

How can I adapt this function to work with (Async, Await, Task)?

  • 772

I have the following function, based on a question I asked a while back here:

How to allow to open multiple instances of a Form under certain specified condition?

public void AbrirFormulario<T>(Func<T> metodofactory,string textoForm = "", bool multiplesInstancias=false) where T : Form
{
  //Buscar el formulario dentro del panel.
  Form formulario;

  if (string.IsNullOrEmpty(textoForm))
      formulario = panel_contenedor.Controls.OfType<T>().FirstOrDefault();
    else 
      formulario = panel_contenedor.Controls.OfType<T>().Where(f => f.Text.Equals(textoForm)).FirstOrDefault();

  if (formulario != null)
  {
     if (string.IsNullOrEmpty(Convert.ToString(formulario.Tag)) ||
         (bool)formulario.Tag==false || formulario.Text == textoForm)
     {
         //Si la instancia esta minimizada la dejamos en su estado normal
         if (formulario.WindowState == FormWindowState.Minimized)
         {
              formulario.WindowState = FormWindowState.Normal;
         }
         //Si la instancia existe la pongo en primer plano
         formulario.BringToFront();
         return;
     }              
 }

 //Se abre el form
 formulario = metodofactory();
 formulario.TopLevel = false;

 if (multiplesInstancias == true)
     formulario.Tag = multiplesInstancias;

 if (multiplesInstancias == true && !string.IsNullOrEmpty(textoForm))
     formulario.Text = textoForm;

 panel_contenedor.Controls.Add(formulario);
 panel_contenedor.Tag = formulario;
 formulario.BringToFront();
 formulario.Show();
}

Which works perfectly fine, but when executing it for example:

AbrirFormulario(() => new Form1(true, "parametro2"), "Titulo", true);

Until the function does not finish doing all the validations, my interface (UI) is blocked, I would like to start using (Async, Await, Task) in this function so that when the function is executed it works, and I can continue using my Interface.

That said, can you help me adapt this function to work with (Async, Await, Task) to work in parallel?

My current work environment is: Visual Studio 2017 with .NetFrameWork 4.5.2

Note: I've never used (Async, Await, Task), it's a bit difficult for me to understand, and I'd like to start with this function to understand how it works.

c#

1 Answers

  1. Best Answer

    It occurs to me that to solve your problem, you can use Task.Run together with async/await and validating InvokeRequired when necessary

    public async Task AbrirFormulario<T>(Func<T> metodofactory, string textoForm = "", bool multiplesInstancias = false) where T : Form
{
    //Hago un await de la tarea
    await Task.Run(() =>
    {
        Form formulario;
        if (string.IsNullOrEmpty(textoForm))
            formulario = panel_contenedor.Controls.OfType<T>().FirstOrDefault();
        else
            formulario = panel_contenedor.Controls.OfType<T>().Where(f => f.Text.Equals(textoForm))
                        .FirstOrDefault();

        if (formulario != null)
        {
            if (string.IsNullOrEmpty(Convert.ToString(formulario.Tag)) || (bool) formulario.Tag == false || formulario.Text == textoForm)
            {
                //Si la instancia esta minimizada la dejamos en su estado normal
                if (formulario.WindowState == FormWindowState.Minimized)
                {
                    formulario.WindowState = FormWindowState.Normal;
                }
                //Si la instancia existe la pongo en primer plano
                formulario.BringToFront();
                return;
            }
        }

        //Se abre el form
        formulario = metodofactory();
        formulario.TopLevel = false;

        if (multiplesInstancias == true)
            formulario.Tag = multiplesInstancias;

        if (multiplesInstancias == true && !string.IsNullOrEmpty(textoForm))
            formulario.Text = textoForm;

        //Valido si es necesario usar un método de invocación o no
        if (InvokeRequired)
        {
            //En caso de serlo, utilizo Invoke para modificar el UI
            this.Invoke(new Action(() =>
            {
                panel_contenedor.Controls.Add(formulario); 
                panel_contenedor.Tag = formulario;
                formulario.BringToFront();
                formulario.Show();
            }));
        }
        //Caso contrario, lo modifico normalmente
        else
        {
            panel_contenedor.Controls.Add(formulario);
            panel_contenedor.Tag = formulario;
            formulario.BringToFront();
            formulario.Show();
        }
    });
}

    Now to call the function, for example on a button

    private async void button1_Click(object sender, EventArgs e)
{
    await AbrirFormulario(() => new Form1(true, "parametro2"), "Titulo", true))
        .ContinueWith((c) => MessageBox.Show("El formulario terminó de cargar."));
}

    Edit: When it comes to duplicating the code, what comes to my mind is to use a function, something like this: 

    public void ModificarUI(Action action)
{
    if (InvokeRequired)
        Invoke(action);
    else
        action();
}

    Then later, when you need, you directly call it like this

    ModificarUI(() => {
            panel_contenedor.Controls.Add(formulario);
            panel_contenedor.Tag = formulario;
            formulario.BringToFront();
            formulario.Show();
        });
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