(C# UWP/WinRT) File Existence Check

Testing to see if a file exists on the FTP server. The GetSizeByName method is a convenient way to check if a file exists. It will return -1 if the file does not exist, otherwise it returns the size of the file in bytes.

Chilkat Universal Windows Platform (UWP) / WinRT Downloads Chilkat for the Universal Windows Platform (UWP)

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

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

ftp.Hostname = "ftp.example.com";
ftp.Username = "username";
ftp.Password = "password";

// Connect and login to the FTP server.
bool success = await ftp.ConnectAsync();
if (success != true) {
    Debug.WriteLine(ftp.LastErrorText);
    return;
}

// Set the current remote directory to where the file is located:
success = await ftp.ChangeRemoteDirAsync("something");
if (success != true) {
    Debug.WriteLine(ftp.LastErrorText);
    return;
}

// Test to see if the file exists by getting the file size by name. 
// If a -1 is returned, the file does not exist.
int fileSize = await ftp.GetSizeByNameAsync("test123.txt");
if (fileSize < 0) {
    Debug.WriteLine("file does not exist");
}
else {
    Debug.WriteLine("file exists and is " + Convert.ToString(fileSize) + " bytes in size");
}

success = await ftp.DisconnectAsync();