Priority Property  
 
Gets and sets a value which specifies the priority of file transfers.

Syntax

object.Priority [= priority ]

Remarks

The Priority property can be used to control the processor usage, memory and network bandwidth allocated for file transfers. One of the following values may be specified:

Value Constant Description
0 ftpPriorityBackground This priority significantly reduces the memory, processor and network resource utilization for the transfer. It is typically used with worker threads running in the background when the amount of time required perform the transfer is not critical.
1 ftpPriorityLow This priority lowers the overall resource utilization for the transfer and meters the bandwidth allocated for the transfer. This priority will increase the average amount of time required to complete a file transfer.
2 ftpPriorityNormal The default priority which balances resource utilization and transfer speed. It is recommended that most applications use this priority.
3 ftpPriorityHigh This priority increases the overall resource utilization for the transfer, allocating more memory for internal buffering. It can be used when it is important to transfer the file quickly, and there are no other threads currently performing file transfers at the time.
4 ftpPriorityCritical This priority can significantly increase processor, memory and network utilization while attempting to transfer the file as quickly as possible. If the file transfer is being performed in the main UI thread, this priority can cause the application to appear to become non-responsive. No events will be generated during the transfer.

The ftpPriorityNormal priority balances resource utilization and transfer speed while ensuring that a single-threaded application remains responsive to the user. Lower priorities reduce the overall resource utilization at the expense of transfer speed. For example, if you create a worker thread to download a file in the background and want to ensure that it has a minimal impact on the process, the ftpPriorityBackground value can be used.

Higher priority values increase the memory allocated for the transfers and increases processor utilization for the transfer. The ftpPriorityCritical priority maximizes transfer speed at the expense of system resources. It is not recommended that you increase the file transfer priority unless you understand the implications of doing so and have thoroughly tested your application. If the file transfer is being performed in the main UI thread, increasing the priority may interfere with the normal processing of Windows messages and cause the application to appear to become non-responsive. It is also important to note that when the priority is set to ftpPriorityCritical, normal progress events will not be generated during the transfer.

Data Type

Integer (Int32)

See Also

GetData Method GetFile Method PutData Method PutFile Method