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我正在编写计算已发送物品价格的蒸汽机器人。我无法正确使用函数。我想从 URL 中获取价格，然后将其添加到 console.log 中。

我做不到，因为 console.log 在循环之前执行。

我真的是 Javascript 的新手，我无法修复它:(

var whole_price = 0;
for(var i=0 ; i<offer.itemsToReceive.length; i++){
    getPrice(offer.itemsToReceive[i].market_hash_name, function(price){
        whole_price += price;
    }); 
}
console.log('Accepted offer from ' + offer.partner + ' with ' + offer.itemsToReceive.length + ' items valued as '+whole_price+'$.' );

获取 URL 价格的函数：

function getPrice(name, callback){
    name = name.replace(/\ +/g, '%20');
    var url = 'http://steamcommunity.com/market/priceoverview/?currency=1&appid=730&market_hash_name='+name;
    var price = 0;


    request(url ,function(error, res, body){
        var useCSGOBACKPACK = false;
        if(!error && res.statusCode == 200){
            body = JSON.parse(body);
            if(body.success == true){
                price = body.median_price.substr(1);
            }else{
                useCSGOBACKPACK = true;
            }
        }else{
            useCSGOBACKPACK = true;
        }

        if(useCSGOBACKPACK==true){
            url = 'http://csgobackpack.net/api/GetItemPrice/?id='+name+'&currency=USD';
            request(url, function(error, res, body){
                body = JSON.parse(body);
                price = body.median_price;
            });
        }

        callback(price);
    });

}
4

2 回答 2

3

做这样的事情的最好方法是......

var whole_price = 0;
var requestsMade = 0;
for(var i=0 ; i<offer.itemsToReceive.length; i++){
    requestsMade++;
    getPrice(offer.itemsToReceive[i].market_hash_name, function(price){
        whole_price += price;
        requestsMade++;

        if(requestsMade == offer.itemsToReceive.length-1)
        {
            console.log(YOUR MESSAGE);
        }
    }); 
}

这基本上是确保您在所有请求都已发出并得到响应之前不会记录消息。这是因为即使所有调用都以特定顺序进行，它们也可能以不同的顺序完成。

于 2016-01-17T21:07:42.673 回答
2

您应该考虑使用异步库，让您的生活更轻松。不要重新发明轮子！

var whole_price = 0;

async.each(offer.itemsToReceive, function (item, next) {

    getPrice(item.market_hash_name, (price) => {
        whole_price += price;
        next();
    });

}, function () {

    console.log(whole_price);
});
于 2016-01-17T22:05:16.787 回答