[align=left][font=宋体][size=3] Via is one of the important components of multi-layer PCB. The cost of drilling holes usually accounts for 30% to 40% of the cost of PCB board manufacturing. Simply put,
I wrote a form (started by default) with a progress bar on it. I want to achieve the following effect: when the form is fully displayed, execute the background program update. Currently, I wrote the u