同步GM

本文介绍了同步GM_xmlhttpRequest异步执行吗?的处理方法，对大家解决问题具有一定的参考价值，需要的朋友们下面随着小编来一起学习吧！ 问题描述

我正在尝试获取GM_xmlhttpRequest调用以使其行为同步，但是我无法使其按预期运行:

I'm trying to get a GM_xmlhttpRequest call to behave synchronously, but I can't get it to work like I expect:

function myFunction (arg) { var a; GM_xmlhttpRequest ( { method: "GET", url: "example/sample/url", synchronous: true, onload: function (details) { a = details.responseText; } } ); return a; } b = myFunction (); alert (b);

在这里，我从没拿到b的任何东西；它是未定义的.我在这里缺少一些步骤吗? 我正在使用Greasemonkey的v0.9.13和Firefox的v9.0.1.

I never get anything back for b here; it's undefined. Is there some step that I'm missing here? I'm using v0.9.13 of Greasemonkey, and v9.0.1 of Firefox.

推荐答案

在Google中偶然发现了这个主题.

Just stumbled upon this topic in Google.

同步GM_xmlhttpRequest返回结果，而不是在onload-callback中执行它.

Synchronous GM_xmlhttpRequest RETURN the result instead of executing it in the onload-callback.

所以这是正确的:

var details = GM_xmlhttpRequest({ method:"GET", url:"site/sample/url", synchronous: true }); a = details.responseText;

您在开头创建了变量"a"，切勿填充并返回它.因此，它是未定义的.

You create the var "a" in the beginning, never fill it and return it. Therefore, it is undefined.