松开鼠标时，仅当鼠标在按下时所在的 GUIElement 或 Collider 上时，才调用 OnMouseUpAsButton。
另请参阅：OnMouseUp。
using UnityEngine;
using System.Collections;
public class ExampleClass : MonoBehaviour {
void OnMouseUpAsButton() {
Application.LoadLevel("SomeLevel");
}
}
在属于 Ignore Raycast 层的对象上，不调用该函数。
This function is called on Colliders marked as Trigger if and only if Physics.queriesHitTriggers is true.
OnMouseUpAsButton can be a co-routine, simply use the yield statement in the function.
This event is sent to all scripts attached to the Collider or GUIElement.