# UploadTask.onProgressUpdate(function callback)
Start from base library version 1.4.0. Please remaining backward compatible.
with Promise style call: Not supported
Mini Program plugin: Support
Monitor upload progress changes
# parameter
# function callback
A callback function for uploading schedule change events
# parameter
# Object res
| attribute | type | Introductions |
|---|---|---|
| progress | number | Percentage of upload progress |
| totalBytesSent | number | The length of data that has been uploaded, in units Bytes |
| totalBytesExpectedToSend | number | Total length of data expected to be uploaded, in units Bytes |