The main problem is that your.wxss file does not set the appropriate properties; For example, if use Animation. Left (number | string value) element to the left, the Animation is a specific execution of Animation from the time of the elements of the left value to the left you new set value; So if you don’t have an attribute in your original element style you’re not going to get the initial value, you’re not going to be able to animate it, so you’re going to do a left assignment and you’re not going to animate it.