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我需要使用 OOP 方式调用一些方法，例如 this.method() 但我得到了一些错误，请这是我的 BingoCard.js 帮助。

var _       = require('underscore');

// ------------------------------------ ---------
// Constructor
// ---------------------------------------------
function BingoCard() {
    if(false === (this instanceof BingoCard)) {
        return new BingoCard();
    }
    this.firstRowSchema  = [];
    this.secondRowSchema = [];
    this.thirdRowSchema  = [];
    this.firstRow  = [];
    this.secondRow = [];
    this.thirdRow  = [];
    this.patterns  = [
    {
       "1" : ['x','0','x','0','x','0','x','x','0'],
       "2" : ['0','x','0','x','0','x','0','x','x'],
       "3" : ['x','0','x','0','x','0','x','0','x']
    },
    {
       "1" : ['x','x','0','x','0','x','0','x','0'],
       "2" : ['0','x','x','0','x','0','x','0','x'],
       "3" : ['x','0','x','x','0','x','0','x','0']
    }
  ];
    this.columns = {
                      "1": [1,2,3,4,5,6,7,8,9],
                      "2": [10,11,12,13,14,15,16,17,18,19],
                      "3": [20,21,22,23,24,25,26,27,28,29],
                      "4": [30,31,32,33,34,35,36,37,38,39],
                      "5": [40,41,42,43,44,45,46,47,48,49],
                      "6": [50,51,52,53,54,55,56,57,58,59],
                      "7": [60,61,62,63,64,65,66,67,68,69],
                      "8": [70,71,72,73,74,75,76,77,78,79],
                      "9": [80,81,82,83,84,85,86,87,88,89,90]
                  };

    // Use Underscore to bind all of our methods
    // to the proper context
    _.bindAll(this);
}
// ---------------------------------------------
// Methods
// ---------------------------------------------
BingoCard.prototype = {  
    resetSchemas: function () {  
        this.firstRowSchema  = [];
        this.secondRowSchema = [];
        this.thirdRowSchema  = []; 
    },  
    generateRows: function () {  
        this.cardID = _.random(8888, 999999999); // generate a Card ID.
        var pattern = _.shuffle(this.patterns);
        this.firstRow   = pattern[0][1];
        this.secondRow  = pattern[0][2];
        this.thirdRow   = pattern[0][3]; 
    },
    createColNumber: function (col,equalNumbers) {
        console.log(this.patterns);
        var colNumber = this.getColNumber(col);
        if(typeof equalNumbers !== 'undefined' && equalNumbers.length > 0){
              equalNumbers.forEach(function(val,key){
                 while(colNumber == val){
                     colNumber = this.getColNumber(col);
                 }
            });
        }
        return colNumber;
    },
    getColNumber: function () {
        var items  = _.shuffle(this.columns[col]);
        return items[0];
    },
    generateFirstRow: function () {
        var col = 0;
        this.firstRow.forEach(function(val,key){
            col++;
            if(val == 'x'){
               this.firstRowSchema[key] = this.createColNumber(col);
            } else {
               this.firstRowSchema[key] = 0;
            }
        });
        return this.firstRowSchema;
    }
}; 

// ---------------------------------------------
// Export
// ---------------------------------------------
module.exports = BingoCard;

我在 app.js 中调用 bingocard 类，这是我的 app.js 内容。

var BingoCard     = require('./bingocard');
var bingocard     = new BingoCard();

bingocard.generateRows();
console.log(bingocard.generateFirstRow());

从控制台运行“节点应用程序”时，我收到此错误：

TypeError: Object #<Object> has no method 'createColNumber'
    at /var/www/bingo/bingocard.js:10:48

但是定义了 createColNumber 方法.. :(？

4

1 回答 1

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在下面代码的第四行，这不是指原型。this指向别的东西。

this.firstRow.forEach(function(val,key){
            col++;
            if(val == 'x'){
               this.firstRowSchema[key] = this.createColNumber(col);
            } else {
               this.firstRowSchema[key] = 0;
            }
        });

你可以通过切换来解决这个this问题self。并在方法定义的开头将其分配给 self 。像这样：

generateFirstRow: function () {
        var col = 0,
            self = this;
        this.firstRow.forEach(function(val,key){
            col++;
            if(val == 'x'){
               self.firstRowSchema[key] = self.createColNumber(col);
            } else {
               self.firstRowSchema[key] = 0;
            }
        });
        return this.firstRowSchema;
    }
于 2013-07-08T10:42:58.577 回答