Summary of the way Unity replaces the UI

1. The UI is processed in the Scene interface

Check 2D on the scene interface

2. Modify the Image in the UI

After creating an Image, directly pull the converted image into Source Image, and finally click SetNative Size.
Then modify it to the corresponding position

3. Modify the buttons in the UI

1. Put A (Normal) in the Iamge of the Button and remember (Set Native Size)
2. Under the Button component, change the Transition to Sprite Swap
3. The first Highlighted Sprite->A (touch)
3. The second Pressed Sprite ->A(click)

4. Anchor point setting in UI

1. Set the anchor point for the unified management empty Gameobject
2. Set the anchor point for other widgets