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 |
filePriorityBackground |
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 |
filePriorityLow |
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 |
filePriorityNormal |
The default priority which balances resource
utilization and transfer speed. It is recommended that most
applications use this priority. |
| 3 |
filePriorityHigh |
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 |
filePriorityCritical |
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 filePriorityNormal 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
filePriorityBackground value can be used.
Higher priority values increase the memory allocated for the
transfers and increases processor utilization for the transfer. The
filePriorityCritical 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 filePriorityCritical,
normal progress events will not be generated during the
transfer.