this is the dialog box of element. The requirement is that when the user clicks the drop-down box to select, enter the number of posts issued. I want to calculate the total price of face value and the total price of unit price. The problem now is that the drop-down box of face value / unit price is spliced into the style of 2x2 by myself, so when the user clicks the selection, it triggers the change event and gets the string "2can2" that the user clicks and selects. Then split ("/") is divided into an array to get the face value, and the unit price, using the calculation attribute, but the calculation attribute will be calculated as soon as it enters the page, but at this time the face value and unit price are empty array, and there is no value, so the report is wrong, all the gods ask for advice! Or is there any other way to solve