字符串。格式慢，需要更快的选择

I was hoping to get some advice on how to speed up the following function. Specifically, I'm hoping to find a faster way to convert numbers (mostly doubles, IIRC there's one int in there) to strings to store as Listview subitems. As it stands, this function takes 9 seconds to process 16 orders! Absolutely insane, especially considering that with the exception of the call to process the DateTimes, it's all just string conversion.I was hoping to get some advice on how to speed