Unicode C

Async Methods Returning an Object

See more Async Examples

Demonstrates how to call an asynchronous method that returns an object. This example reads email from a POP3 server using the Async versions of the Chilkat methods. Unicode C

#include <C_CkMailManW.h>
#include <C_CkTaskW.h>
#include <C_CkEmailW.h>

void ChilkatSample(void)
    {
    BOOL success;
    HCkMailManW mailman;
    HCkTaskW task;
    int maxWaitMs;
    int numMessages;
    HCkEmailW email;
    int i;

    success = FALSE;

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

    success = FALSE;

    mailman = CkMailManW_Create();

    // Set the POP3 server's hostname
    CkMailManW_putMailHost(mailman,L"pop.example.com");

    // Set the POP3 login/password and any other requirements..
    CkMailManW_putPopUsername(mailman,L"myLogin");
    CkMailManW_putPopPassword(mailman,L"myPassword");
    CkMailManW_putPopSsl(mailman,TRUE);
    CkMailManW_putMailPort(mailman,995);

    // Connect to the POP3 server:
    task = CkMailManW_Pop3BeginSessionAsync(mailman);
    if (CkMailManW_getLastMethodSuccess(mailman) == FALSE) {
        wprintf(L"%s\n",CkMailManW_lastErrorText(mailman));
        CkMailManW_Dispose(mailman);
        return;
    }

    // Start the background task.
    success = CkTaskW_Run(task);
    if (!success) {
        wprintf(L"%s\n",CkTaskW_lastErrorText(task));
        CkTaskW_Dispose(task);
        CkMailManW_Dispose(mailman);
        return;
    }

    // Wait for the POP3 connect task to finish.
    // The TRUE/FALSE returned by Wait applies to the Wait method call, not the task.
    maxWaitMs = 30000;
    success = CkTaskW_Wait(task,maxWaitMs);
    if (!success || (CkTaskW_getStatusInt(task) != 7) || (CkTaskW_getTaskSuccess(task) != TRUE)) {
        if (!success) {
            // The task.LastErrorText applies to the Wait method call.
            wprintf(L"%s\n",CkTaskW_lastErrorText(task));
        }
        else {
            // The ResultErrorText applies to the underlying task method call (i.e. the Pop3BeginSession)
            wprintf(L"%s\n",CkTaskW_status(task));
            wprintf(L"%s\n",CkTaskW_resultErrorText(task));
        }

        CkTaskW_Dispose(task);
        CkMailManW_Dispose(mailman);
        return;
    }

    CkTaskW_Dispose(task);

    // Get the number of messages in the mailbox.
    task = CkMailManW_GetMailboxCountAsync(mailman);

    // To keep the example short, we'll skip handling failures.
    // The failures would be handled in the same way as shown above.

    success = CkTaskW_Run(task);
    success = CkTaskW_Wait(task,maxWaitMs);
    numMessages = CkTaskW_GetResultInt(task);
    CkTaskW_Dispose(task);
    if (numMessages == 0) {
        CkMailManW_Dispose(mailman);
        return;
    }

    email = CkEmailW_Create();

    for (i = 1; i <= numMessages; i++) {

        task = CkMailManW_FetchByMsgnumAsync(mailman,i);
        if (CkMailManW_getLastMethodSuccess(mailman) == FALSE) {
            wprintf(L"%s\n",CkMailManW_lastErrorText(mailman));
            CkMailManW_Dispose(mailman);
            CkEmailW_Dispose(email);
            return;
        }

        success = CkTaskW_Run(task);
        success = CkTaskW_Wait(task,maxWaitMs);
        if (!success || (CkTaskW_getStatusInt(task) != 7) || (CkTaskW_getTaskSuccess(task) != TRUE)) {
            if (!success) {
                // The task.LastErrorText applies to the Wait method call.
                wprintf(L"%s\n",CkTaskW_lastErrorText(task));
            }
            else {
                // The ResultErrorText applies to the underlying task method call (i.e. the FetchByMsgnum)
                wprintf(L"%s\n",CkTaskW_status(task));
                wprintf(L"%s\n",CkTaskW_resultErrorText(task));
            }

            CkTaskW_Dispose(task);
            CkMailManW_Dispose(mailman);
            CkEmailW_Dispose(email);
            return;
        }

        // Each Chilkat object that can be a return value of an asynchronous task will
        // have a method named LoadTaskResult.  The object returned in the underlying
        // asynchronous method call is retrieved by calling LoadTaskResult. 

        // To say it another way: The application will provide a pre-existing object of
        // the desired return type (in this case it is an email object).  This object is
        // loaded by calling LoadTaskResult.  

        success = CkEmailW_LoadTaskResult(email,task);
        CkTaskW_Dispose(task);

        if (!success) {
            wprintf(L"%s\n",CkEmailW_lastErrorText(email));
            CkMailManW_Dispose(mailman);
            CkEmailW_Dispose(email);
            return;
        }
        else {
            wprintf(L"%s: %s\n\n",CkEmailW_ck_from(email),CkEmailW_subject(email));
        }

    }



    CkMailManW_Dispose(mailman);
    CkEmailW_Dispose(email);

    }