How to create timer on JINT Javascript side

问题:

I´m developing a C# project using JINT (https://github.com/sebastienros/jint), and I need to create a timer on my JS so it can execute a function on my javascript every time the timer tim set is elapsed. How can I accomplish that?. I have used setInterval or setTimeout functions but it seems that they are not part of JINT since it is based on ECMASCRIPT and this functions are not native.

Can someone tell me how I can do this?.

Thanks!!

回答1:

Neither setInterval and setTimeout are supported by Jint because they are part of the Window API in browsers. with Jint, instead of browser, we have access to CLR, and to be honest it's much more versatile.

First step is to implement our Timer in CLR side, Here is an extremely simple Timer wrapper for built-int System.Threading.Timer class:

namespace JsTools
{
    public class JsTimer
    {
        private Timer _timer;
        private Action _actions;

        public void OnTick(Delegate d)
        {
            _actions += () => d.DynamicInvoke(JsValue.Undefined, new[] { JsValue.Undefined });
        }

        public void Start(int delay, int period)
        {
            if (_timer != null)
                return;

           _timer = new Timer(s => _actions());
           _timer.Change(delay, period);
        }

        public void Stop()
        {
            _timer.Dispose();
            _timer = null;
        }
    }
}

Next step is to bind out JsTimer to Jint engine:

var engine = new Engine(c => c.AllowClr(typeof (JsTimer).Assembly))

Here is an usage example:

internal class Program
{
    private static void Main(string[] args)
    {
        var engine = new Engine(c => c.AllowClr(typeof (JsTimer).Assembly))
            .SetValue("log", new Action<object>(Console.WriteLine))
            .Execute(
                @" 
var callback=function(){
   log('js');
}
var Tools=importNamespace('JsTools');
var t=new Tools.JsTimer();
t.OnTick(callback);
t.Start(0,1000);
");

        Console.ReadKey();
    }
}