(MFC) Async FTP Progress Info

Demonstrates checking for progress info updates when running a task asynchronously. This example demonstrates an FTP download.

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

See Also: Using MFC CString in Chilkat

#include <CkFtp2.h>
#include <CkTask.h>

void ChilkatSample(void)
    {
    CkString strOut;

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

    CkFtp2 ftp;

    ftp.put_Hostname("ftp.someFtpServer.com");
    bool success = ftp.ConnectOnly();
    if (success != true) {
        strOut.append(ftp.lastErrorText());
        strOut.append("\r\n");
        SetDlgItemText(IDC_EDIT1,strOut.getUnicode());
        return;
    }

    ftp.put_Username("myLogin");
    ftp.put_Password("myPassword");
    success = ftp.LoginAfterConnectOnly();
    if (success != true) {
        strOut.append(ftp.lastErrorText());
        strOut.append("\r\n");
        SetDlgItemText(IDC_EDIT1,strOut.getUnicode());
        return;
    }

    // Change to the remote directory where the file is located.
    // This step is only necessary if the file is not in the root directory
    // for the FTP account.
    success = ftp.ChangeRemoteDir("someRemoteDirectory");
    if (success != true) {
        strOut.append(ftp.lastErrorText());
        strOut.append("\r\n");
        SetDlgItemText(IDC_EDIT1,strOut.getUnicode());
        return;
    }

    const char *localFilename = "/temp/romeo.xml";
    const char *remoteFilename = "romeo.xml";

    // --------------------
    // Download a file
    // --------------------

    // Call the async version of the GetFile method to return a task object.
    // The task object is loaded, but is in the Inert state -- meaning it is
    // not yet scheduled to run on Chilkat's background thread pool.
    CkTask *task = ftp.GetFileAsync(remoteFilename,localFilename);
    if (ftp.get_LastMethodSuccess() == false) {
        strOut.append(ftp.lastErrorText());
        strOut.append("\r\n");
        SetDlgItemText(IDC_EDIT1,strOut.getUnicode());
        return;
    }

    // Before starting the task, tell it to keep an in-memory log of what would've been
    // ProgressInfo callbacks.
    task->put_KeepProgressLog(true);

    // Schedule the task for running on the thread pool.  This changes the task's state
    // from Inert to Live.
    success = task->Run();
    if (success != true) {
        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 file is being downloaded.

    // For this example, we'll simply sleep and periodically
    // check to see if the download is finished, and report the progress
    // along the way.
    int curPctDone = 0;
    const char *name = 0;
    const char *value = 0;

    while (task->get_Finished() != true) {

        if (task->get_PercentDone() != curPctDone) {
            curPctDone = task->get_PercentDone();
            strOut.appendInt(curPctDone);
            strOut.append(" percent done");
            strOut.append("\r\n");
        }

        // Check the progress info log.
        // Emit any log entries..
        while ((task->get_ProgressLogSize() > 0)) {
            // Get the 1st entry, emit it, and then remove it..
            name = task->progressInfoName(0);
            value = task->progressInfoValue(0);

            // Entries reporting the received byte count will have the name "RcvByteCount"
            // Entries reporting the current bytes-per-second will have the name "RcvBytesPerSec"

            strOut.append(name);
            strOut.append(": ");
            strOut.append(value);
            strOut.append("\r\n");
            task->RemoveProgressInfo(0);
        }

        // Sleep 100 ms.
        task->SleepMs(100);

    }

    // Just in case there are any remaining entries...
    while ((task->get_ProgressLogSize() > 0)) {
        // Get the 1st entry, emit it, and then remove it..
        name = task->progressInfoName(0);
        value = task->progressInfoValue(0);
        strOut.append(name);
        strOut.append(": ");
        strOut.append(value);
        strOut.append("\r\n");
        task->RemoveProgressInfo(0);
    }

    // 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 GetFile method returns a boolean.  Therefore, after the task is finished,
    // we can get the boolean result by calling GetResultBool.  This is the return value had
    // we called GetFile synchronously.
    success = task->GetResultBool();
    if (success != true) {
        // The task's ResultErrorText contains what would have been in the LastErrorText property had
        // the GetFile method been called synchronously.
        strOut.append(task->resultErrorText());
        strOut.append("\r\n");
    }
    else {
        strOut.append("File downloaded asynchronously.");
        strOut.append("\r\n");
    }

    delete task;

    success = ftp.Disconnect();


    SetDlgItemText(IDC_EDIT1,strOut.getUnicode());

    }