打字稿表达中间件

Question

我有一个简单的auth中间件用于表达.它检查标题,如果所有酷,它调用next()

现在,当我在"DoSomething"中时,"this"等于全局,而不是"Test"和"this.DoSomeThingPrivate"的实例未定义.

我试过了

DoSomeThingPrivate :() => void;

this.DoSomeThingPrivate = () => {
...
}

图案.但也行不通.

import express = require('express');

var app = express();

class Test {    
    constructor() {        
    }

    DoSomething(req:express.Request, res:express.Response, next:Function) :void {       
        this.DoSomeThingPrivate();
    }

    private DoSomeThingPrivate() :void
    {       
    }
}

var test = new Test();

app.use(test.DoSomething);

与此有关

有任何想法吗...

谢谢

Answer 1

以下应该工作正常,但DoSomething不使用胖箭头DoSomethingPrivate:

import express = require('express');

var app = express();

class Test {    
    constructor() {        
    }

    // important: 
    DoSomething = (req:express.Request, res:express.Response, next:Function) => {       
        this.DoSomeThingPrivate();
    }

    private DoSomeThingPrivate() :void
    {       
    }
}

var test = new Test();

app.use(test.DoSomething);

注意:您不应该使用bind.另请https://www.youtube.com/watch?v=KDrWLMUY0R0&hd=1

Answer 2

您已经将参考传递给函数本身.该函数的实例将是全局的.您需要将函数绑定到实例test.

app.use(test.DoSomething.bind(test));