I was watching a tutorial video made on the web recently,Noticed that the instructor used a certain tool,You can drag the mouse cursor on the browser screen,The length and width of the drag appear instantly,This way when you want to know the size of the page element,Very convenient。After not finding the relevant function in Firefox,Then go to the plugin component to start,After a goo,In addition to related plugins,It turns out that Firefox is built-in,I just have to manually turn it on。
