Time.timeAsDouble

描述

该帧开始的时间（只读）。此为自游戏启动以来的时间（以秒为单位）。

Time.timeAsDouble is the amount of time in seconds that the application has been running for. It is read-only.

Double precision version of time. This offers more precision than a float or single value, particularly over extended periods of real-world time. In almost all cases, choose the timeAsDouble equivalent over time.

The application receives the current Time.timeAsDouble at the beginning of each frame, with the value increasing per frame. A timeAsDouble call per frame receives the same value. When called from FixedUpdate it returns the Time.fixedTimeAsDouble property.

Regular (per frame) calls should be avoided: Time.timeAsDouble is intended to supply the length of time the application has been running for, and not the time per frame.

The value of Time.timeAsDouble is undefined during Awake messages and will start after all messages are finished. Time.timeAsDouble will not update if the Editor is paused. See Time.realtimeSinceStartupAsDouble for a time value that is unaffected by pausing.

//If the Fire1 button is pressed, a projectile
//will be Instantiated every 0.5 seconds.

using UnityEngine;
using System.Collections;

public class Example : MonoBehaviour
{
    public GameObject projectile;
    public float fireRate = 0.5f;
    private double nextFire = 0.0f;

    void Update()
    {
        if (Input.GetButton("Fire1") && Time.timeAsDouble > nextFire)
        {
            nextFire = Time.timeAsDouble + fireRate;
            Instantiate(projectile, transform.position, transform.rotation);
        }
    }
}