如何等待回调函数返回？ [英] How to wait till callback function returns?

问题描述

我正在使用phonegap安卓应用程序。我使用phonegap的存储api查询数据库。这里是我的代码：

I'm making an android application using phonegap. I'm using phonegap's Storage api for querying a database. here's my code:

function directPath(src, dest)
{
    var db = window.openDatabase("Database", "1.0", "PhoneGap Demo", 200000);
    db.transaction(queryDB, errorCB);
    return arrayroute;
}

function queryDB(tx)
{
    tx.executeSql(query, [], querySuccess, errorCB);
}

function querySuccess(tx,results) {
    //Write some code here.
}

function errorCB(err) {
    alert("Error in SQL: " + err);
}

问题是我想等待回调方法querySuccess完成执行，然后返回从directPath方法。

The problem is I want to wait till the callback method querySuccess finishes execution before returning from the directPath method.

推荐答案

不要试图打击异步：你的应用程序可能最终似乎对用户无反应。对任何必须执行的代码使用querySuccess回调。

Don't try to fight the asynchrony: Your app might end up seeming unresponsive to the user. Use the querySuccess callback for any code that has to be executed afterwards.

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