在canvas下挂脚本
[Tooltip("Determines if a UI Click action should happen when a UI Pointer game object collides with this canvas.")]
public bool clickOnPointerCollision = false;
[Tooltip("Determines if a UI Pointer will be auto activated if a UI Pointer game object comes within the given distance of this canvas. If a value of `0` is given then no auto activation will occur.")]
public float autoActivateWithinDistance = 0f;