(C#) Async FTP Progress Info

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

Chilkat .NET Downloads Chilkat .NET Framework Chilkat for .NET Core

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

Chilkat.Ftp2 ftp = new Chilkat.Ftp2();

ftp.Hostname = "ftp.someFtpServer.com";
bool success = ftp.ConnectOnly();
if (success != true) {
    Debug.WriteLine(ftp.LastErrorText);
    return;
}

ftp.Username = "myLogin";
ftp.Password = "myPassword";
success = ftp.LoginAfterConnectOnly();
if (success != true) {
    Debug.WriteLine(ftp.LastErrorText);
    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) {
    Debug.WriteLine(ftp.LastErrorText);
    return;
}

string localFilename = "/temp/romeo.xml";
string 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.
Chilkat.Task task = ftp.GetFileAsync(remoteFilename,localFilename);
if (ftp.LastMethodSuccess == false) {
    Debug.WriteLine(ftp.LastErrorText);
    return;
}

// Before starting the task, tell it to keep an in-memory log of what would've been
// ProgressInfo callbacks.
task.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) {
    Debug.WriteLine(task.LastErrorText);

    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;
string name;
string value;

while (task.Finished != true) {

    if (task.PercentDone != curPctDone) {
        curPctDone = task.PercentDone;
        Debug.WriteLine(Convert.ToString(curPctDone) + " percent done");
    }

    // Check the progress info log.
    // Emit any log entries..
    while ((task.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"

        Debug.WriteLine(name + ": " + value);
        task.RemoveProgressInfo(0);
    }

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

}

// Just in case there are any remaining entries...
while ((task.ProgressLogSize > 0)) {
    // Get the 1st entry, emit it, and then remove it..
    name = task.ProgressInfoName(0);
    value = task.ProgressInfoValue(0);
    Debug.WriteLine(name + ": " + value);
    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.StatusInt != 7) {
    Debug.WriteLine("Task did not complete.");
    Debug.WriteLine("task status: " + task.Status);

    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.
    Debug.WriteLine(task.ResultErrorText);
}
else {
    Debug.WriteLine("File downloaded asynchronously.");
}

success = ftp.Disconnect();