我怎么能在子代码中使用父变量？

Question

该代码使用继承的孩子，我在场景中添加一些东西，在父声明我怎么能做到这一点得到它在看到现场错误的子级别

function parent (domElement, renderStatistics) { 
    this.scene = new THREE.Scene(); 
    } 
function child(domElement) { 
    parent.call(this, domElement); 
    this.init(); 
} 
child.prototype = Object.create(parent.prototype); 

child.prototype.constructor = Young; 


child.prototype.init = function() { 
function createLab(geometry) { 
     var mesh = new THREE.Mesh(geometry, new THREE.MeshFaceMaterial()); 
     this.scene.add(mesh); // this error Cannot call method 'add' of undefined 
    } 
} 

Answer 1

child.prototype.init = function() { 
var _this = this; 
    function createLab(geometry) { 
     var mesh = new THREE.Mesh(geometry, new THREE.MeshFaceMaterial()); 
     _this.scene.add(mesh); 
    } 
} 

Answer 2

我不知道为什么你需要创建内部初始化内部函数...

尝试要么

child.prototype.init = function() { 
     var mesh = new THREE.Mesh(geometry, new THREE.MeshFaceMaterial()); 
     this.scene.add(mesh); // this error Cannot call method 'add' of undefined 
} 

或者

function createLab(geometry) { 
    var mesh = new THREE.Mesh(geometry, new THREE.MeshFaceMaterial()); 
    this.scene.add(mesh); // this error Cannot call method 'add' of undefined 
}; 

child.prototype.init = function() { 
    createLab.call(this, whatever); 
} 

Answer 3

看起来像你的错误的原因是在第二行的双等于= =。

这导致值的归属是一个布尔值，而不是你所期望的新的THREE.Mesh的实例。