(MFC) Async Methods Returning an String

Demonstrates how to call an asynchronous method that returns a string. This example sends an HTTPS GET request to a URL and gets the HTML response.

Chilkat C/C++ Library Downloads MS Visual C/C++ Libs

See Also: Using MFC CString in Chilkat

#include <CkHttp.h>
#include <CkTask.h>

void ChilkatSample(void)
    {
    CkString strOut;

    // This example requires the Chilkat API to have been previously unlocked.
    // See Global Unlock Sample for sample code.

    CkHttp http;

    CkTask *task = http.QuickGetStrAsync("https://www.chilkatsoft.com/helloWorld.html");
    if (http.get_LastMethodSuccess() == false) {
        strOut.append(http.lastErrorText());
        strOut.append("\r\n");
        SetDlgItemText(IDC_EDIT1,strOut.getUnicode());
        return;
    }

    // Start the background task.
    bool success = task->Run();
    if (!success) {
        strOut.append(task->lastErrorText());
        strOut.append("\r\n");
        delete task;
        SetDlgItemText(IDC_EDIT1,strOut.getUnicode());
        return;
    }

    // The application is now free to do anything else
    // while the email is being sent.

    // For this example, we'll simply sleep and periodically
    // check to see if the HTTPS GET if finished.
    while (task->get_Finished() != true) {
        // Sleep 100 ms.
        task->SleepMs(100);
    }

    // A finished task could be one that was canceled, aborted, or truly finished.  

    // If the task was "canceled", it was canceled prior to actually starting.  This could
    // happen if the task was canceled while waiting in a thread pool queue to be scheduled by Chilkat's
    // background thread pool scheduler.  

    // If the task was "aborted", it indicates that it was canceled while running in a background thread.  
    // The ResultErrorText will likely indicate that the task was aborted.

    // If the task "completed", then it ran to completion, but the actual success/failure of the method
    // is determined by the result obtained via a GetResult* method.  (A "completed" task will
    // have a StatusInt equal to 7.   If the task finished, but was not completed, then it must've
    // been aborted or canceled:
    if (task->get_StatusInt() != 7) {
        strOut.append("Task did not complete.");
        strOut.append("\r\n");
        strOut.append("task status: ");
        strOut.append(task->status());
        strOut.append("\r\n");
        delete task;
        SetDlgItemText(IDC_EDIT1,strOut.getUnicode());
        return;
    }

    // The QuickGetStr method returns a string.  Therefore, after the task is finished,
    // we can get the string result by calling GetResultString.  This is the return value had
    // we called QuickGetStr synchronously.
    const char *html = task->getResultString();

    strOut.append(html);
    strOut.append("\r\n");

    delete task;


    SetDlgItemText(IDC_EDIT1,strOut.getUnicode());

    }