我正在尝试在 node.js 中创建一个模块/类来测量异步执行时间,但不明白它有什么问题。我创建了以下类“Measure.js”
var Measure = module.exports = function(param_timeout, param_cb) {
this.timeout = param_timeout;
this.cb = param_cb;
}
Measure.prototype = {
startDate: "0",
timeout:"0",
cb:null,
start : function() {
this.startDate = new Date();
console.log('started');
},
stop : function() {
var stopDate = new Date();
this.cb(null,(stopDate-this.startDate));
}
}
我将它与以下代码一起使用:
var Measure = require('./Measure.js');
measure1 = new Measure(100,function(err,result){console.log('result: ' + result)});
measure1.start();
//do something
measure1.stop();
它工作得很好。但是,如果我尝试这个:
var Measure = require('./Measure.js');
measure1 = new Measure(100,function(err,result){console.log('result: ' + result)});
measure1.start();
//do something
setTimeout(measure1.stop,100);
它不起作用并引发 TypeError:
TypeError: Object #<Object> has no method 'cb'
我的代码有什么问题?