请耐心等待我，因为我只是刚刚进入JavaScript并且我在JOP中完全是OOP，所以...有人可以帮我解决我的问题吗？ （请原谅我代码中的长度和注释）
开始：我创建了2个对象：Product，Basket 通过＆＃39; createProductRows（）＆＃39;在线创建表格。函数传递一组Product对象。这将打印出产品信息并创建一个按钮，将产品添加到购物篮中。它的按钮（或者其他东西）给了我这个问题。 *我希望按钮使用productList数组中的产品索引调用addProduct（）函数，该数组又调用2个函数;篮子对象中的addToBasket（）和display（）..这应该将创建的元素添加到购物篮表中
我不确定我是否正确传递了productList数组，或者我应该使用原型进行Basket方法，任何有助于正常工作的帮助都会非常感激。感谢
var productList = []; // array where product objects are to be held
var basket;
var obj;
//product constructor
var Product = function(name, description, quantity, price, gender) {
obj = this; // a reference to this object //could use
this.name = name;
this.description = description;
this.quantity = quantity;
this.price = price.toFixed(2);
this.gender = gender;
};
//product prototypes
Product.prototype = {
toString: function() { return this.name.toLowerCase(); }
};
Product.prototype.getPrice = function() {
return '\u00A3' + this.price;
};
Product.prototype.getQuantity = function() {
return this.quantity;
};
//instantiate new products
var shorts = new Product('Shorts', 'Stone Wash Demin Shorts', 20, 25.90, 'F');
var bag = new Product('Bag', 'Leather Shoulder Bag', 4, 50.45, 'F');
var blouse = new Product('Blouse', 'Vintage Blue Silk Polka Dot Blouse', 8, 45.99, 'F');
var boots = new Product('Boots', 'Soft Leather Brown Ankle Boots', 3, 65.35, 'F');
var belts = new Product('Belts', 'Woven Finish Fashion Belt', 15, 21.99, 'F');
var shirt = new Product('Shirt', 'Jacquard Pattern Wrangler Western Shirt', 19, 34.87, 'M');
var shoes = new Product('Shoes', 'Suede Ankle Boots', 6, 55.00, 'M');
var trousers = new Product('Trousers', 'Izod Peach Chinos', 23, 31.75, 'M');
var belt = new Product('Belt', 'Suede Casual Belt', 4, 22.98, 'M');
var hat = new Product('Hat', 'Trilby Style Brown Woven Fix', 2, 67.80, 'M');
//push all product objects to an array
productList.push(shorts, bag, blouse, boots, belts, shirt, shoes, trousers, belt, hat);
// basket constructor
var Basket = function(container, products) { // passes in the product list
this.container = container; // this tells me where to add the data
this.products = products; //reference to product values
this.quantity = []; // stores quantities in bag
for (var i=0; i < products.length; i++) { //find product
this.quantity[i] = 0; //amount of each product in basket
// method to add to basket
this.addToBasket = function(index) { //reference to the product to add
this.quantity[index]++;
this.products[i].quantity--; // minus one from the products list
};
// method to remove from basket
this.removeFromBasket = function(index) {
if (this.quantity[index] > 0)
this.quantity[index]--;
this.products[i].quantity++;
};
//displays product
this.display = function () {
for (var i=0; i < this.quantity.length; i++) {
if (this.quantity[i] > 0) {
var tbl = this.container
var row = tbl.insertRow(tbl.rows.length); // create a row element to append cells to
var total_price = this.quantity[i] * this.products[i].price;
//cell values
var desc = this.products[i].description; //for each value add new cell
var qty = this.quantity[i]
var price = this.products[i].price;
var total = total_price;
var remove = createRemoveBtn();
var cell = tbl.rows[i].insertCell(-1); // add a new cell, inserted at end of each row
//append cells
cell.appendChild(desc);
cell.appendChild(qty);
cell.appendChild(price);
cell.appendChild(total);
cell.appendChild(remove);
tbl.appendChild(row); // finally append the rows to the table
function createRemoveBtn() {
var btn = document.createElement('input');
var buttonName = products[i].name.toUpperCase();
btn.type = 'button';
btn.value = 'Remove';
btn.id = buttonName[i]; //append button names from object name
btn.onclick = function() {removeProduct(i);}; //test
return btn;
};//end function 'createRemoveBtn()'
};//end if 'quantity'
};//end for 'basket'
};//end function 'this.display()'
};//end for 'products'
};//end Object 'Basket'
//create a new instance of the Basket object
basket = new Basket(document.getElementById('basketTable').getElementsByTagName('tbody')[0], productList); // *** need to create a new container for the basket
//button functions
function addProduct(item) { //add to basket function
basket.addToBasket(item);
basket.display();
alert(productList[item].name + ' added to basket');
}
function removeProduct(item) { //remove item from basket
basket.removeFromBasket(item);
basket.display();
alert(productList[item].name + ' removed to basket');
}
//displays product table which is called on the body onload event
function createProductRows(products) { // passing in productList[]
var tbl = document.getElementById('productTable').getElementsByTagName('tbody')[0]; // reference to the table to add rows to in the table body
for (var i=0; i < products.length; i++) { // index the productsList (iterate through 0-9)
var myProduct = products[i]; // keep a reference to each individual product - shorts, bag, blouse, etc...
var myRow = tbl.insertRow(tbl.rows.length); // create a row element to append cells to
var myProperties = ['name', 'description', 'quantity', 'price', 'gender']; //store the property names of the products, references to the object data
for (var j=0; j < myProperties.length; j++) // for each property in myProperties [0-4]
{
var myCell = myRow.insertCell(j); //create table cell element
var data = myProduct[myProperties[j]]; // store property values of products
var node = document.createTextNode(data); //add the data to a text node
myCell.appendChild(node); // append text node to table cell
myRow.appendChild(myCell); // add to end of the row
}
var newCell = tbl.rows[i].insertCell(-1); // create a new cell, inserted at end of each row
newCell.appendChild(createAddBtn()); // add buttons to cells
tbl.appendChild(myRow); // finally append the rows to the table
function createAddBtn() {
var btn = document.createElement('input');
var buttonName = products[i].name.toLowerCase(); // to be added to the button's id value
btn.type = 'button';
btn.value = 'Add';
btn.id = buttonName; //append button names from object name
btn.onclick = function() {addProduct(i);};
return btn;
};
};
};
答案 0 :(得分：0)
<强> [更新]
在您的情况下，问题可能在于您创建闭包的方式：
btn.onclick = function() {addProduct(i);};
您可以尝试登录并查看控制台以查看i的值是什么：
btn.onclick = function() {console.log('and i is:',i);addProduct(i);};
在循环中创建闭包时，i的值不是您想象的那样，您可以使用IIFE来解决它：
btn.onclick = (function(index) {
return function(){
console.log('and index is:',index);
addProduct(index);
};
}(i));
设置事件处理程序的问题是你得到了错误的调用对象。
以下是关于调用对象的以下answer的副本：
这个变量
在所有示例代码中，您将看到这涉及当前实例。
this变量实际上是指调用对象，它指的是函数之前的对象。
要澄清，请参阅以下代码：
theInvokingObject.thefunction();
这会引用错误对象的实例通常是在附加事件侦听器，回调或超时和间隔时。在接下来的两行代码中，我们传递了函数，我们不会调用它。传递函数是：someObject.aFunction并调用它是：someObject.aFunction（）。该值不是指声明函数的对象，而是指调用它的对象。
setTimeout(someObject.aFuncton,100);//this in aFunction is window
somebutton.onclick = someObject.aFunction;//this in aFunction is somebutton
要在上述情况下进行此操作，请参阅someObject，您可以直接传递闭包而不是函数：
setTimeout(function(){someObject.aFuncton();},100);
somebutton.onclick = function(){someObject.aFunction();};