How to probe the file upload url of a given web

Hi, Support:
Would you please teach me how to probe the file upload url of a given web so that I can use api to simulate posting a local file to a website or web database?
for example:
There is a site such as 登录百度帐号, in which there is a button “add new document…”. By pressing the button, a file upload dialogue message box will display, then locate the file location for uploading, then the message box will close and file-uploading is in progress.
If Pressing F12 to view the source codes of the web page, there find no url for uploading file, actually, the Url for posting data for uploading file may be : 登录百度帐号
Here, my request is that how to use your httpwatch to probe the POST URL like “https://cuttlefish.baidu.com/shopmis#/commodityManage/documentation/default.php?UserID=myid&password=mypwd&uploadfile=C:\Test\TestFileForUpload.doc&category=1&price=25.00
If so, We can use api to simulate posting localfile uploading to website without displaying the file opening dialogue.
Thanks for your help!

Hi Ducaisoft,

The URL you mentioned requires a login. However, we do have a file upload example on our web site:

https://www.httpwatch.com/httpgallery/methods/#showExample6c

If you start recording in Chrome with HttpWatch on this page and then click on the Submit button you’ll see a POST request. For file uploads the request body uses the mime type multi-part/form-data:

If you then click on the ‘View As’ menu and select ‘Source Text’ you’ll see the format of the request body using multi-part/form-data to separate values:

Unfortunately, the debugging interface to Chrome always omits the actual file contents. The picture below shows where the file contents should appear:

If you use HttpWatch in Internet Explorer there is no such restriction and you can see the full contents of the request body.