Call Async Method in Page_Load

Question

static async void SendTweetWithSinglePicture(string message, string image)
{
    var auth = new SingleUserAuthorizer
    {
        CredentialStore = new SingleUserIn         


        

Answer 1

The question is if you want to make the Page_Load method async or not. If so:

protected async void Page_Load(object sender, EventArgs e)
{
    await SendTweetWithSinglePicture("test", "path");
}

Or if you don't want it to be async:

protected void Page_Load(object sender, EventArgs e)
{
    SendTweetWithSinglePicture("test", "path").Wait();
}

This does require your async method to return Task as it always should! (except event handlers)

The problem with this might be that the method doesn't complete before rendering the page. If it has to, you'd better make the method synchronous, or register the task using Page.RegisterAsyncTask and Page.ExecuteRegisteredAsyncTasks. Effectively this will freeze the Page_Load method too.

protected void Page_Load(object sender, EventArgs e)
{
    PageAsyncTask t = new PageAsyncTask(SendTweetWithSinglePicture("test", "path"));

    // Register the asynchronous task.
    Page.RegisterAsyncTask(t);

    // Execute the register asynchronous task.
    Page.ExecuteRegisteredAsyncTasks();
}

Answer 2

Try This :

 public void Page_Load(object sender, EventArgs e)
{
    RegisterAsyncTask(new PageAsyncTask(LoadSomeData));
}

public async Task LoadSomeData()
{

    var clientcontacts = Client.DownloadStringTaskAsync("api/contacts");
    var clienttemperature =     Client.DownloadStringTaskAsync("api/temperature");
    var clientlocation = Client.DownloadStringTaskAsync("api/location");

    await Task.WhenAll(clientcontacts, clienttemperature, clientlocation);

    var contacts =     Newtonsoft.Json.JsonConvert.DeserializeObject<List<Contact>>(await clientcontacts);
    var location = Newtonsoft.Json.JsonConvert.DeserializeObject<string>(await clientlocation);
    var temperature = Newtonsoft.Json.JsonConvert.DeserializeObject<string>(await clienttemperature);

    listcontacts.DataSource = contacts;
    listcontacts.DataBind();
    Temparature.Text = temperature;
    Location.Text = location;
}

Answer 3

You should use PageAsyncTask. It has samples in MSDN page.

// Register the asynchronous task.
Page.RegisterAsyncTask(new PageAsyncTask(SendTweetWithSinglePicture(message, image));

// Execute the register asynchronous task.
Page.ExecuteRegisteredAsyncTasks();

as I pointed the sample and explanations on MSDN page is pretty good.