javascript XMLHttpRequest：Access-Control-Allow-Origin 不允许 Origin null
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XMLHttpRequest: Origin null is not allowed by Access-Control-Allow-Origin
提问by Rocket Hazmat
Possible Duplicate:
XmlHttpRequest error: Origin null is not allowed by Access-Control-Allow-Origin
XMLHttpRequest cannot load file://… Origin null is not allowed by Access-Control-Allow-Origin
可能的重复：
XmlHttpRequest 错误：Access-Control-Allow-Origin 不允许 Origin null
XMLHttpRequest 无法加载文件：//... Access-Control-Allow-Origin 不允许 Origin null
I am trying to open my JSON file such as:
我正在尝试打开我的 JSON 文件，例如：
jQuery.getJSON('../data/json/en/nodesData.json',
function(data){
jQuery.each(data, function(){
//do something...
})
})
this yields the following error in Chrome:
这会在 Chrome 中产生以下错误：
XMLHttpRequest cannot load file:///C:/URL/data/json/en/nodesData.json. Origin null is not allowed by Access-Control-Allow-Origin
XMLHttpRequest 无法加载 file:///C:/URL/data/json/en/nodesData.json。Access-Control-Allow-Origin 不允许 Origin null
what's problem? How can I retrieve my json?
什么问题？我怎样才能检索我的json？
回答by epascarello
You really should be running a local server like Apache or IIS to run HTML/JavaScript code so you do not run into these restrictions.
您确实应该运行像 Apache 或 IIS 这样的本地服务器来运行 HTML/JavaScript 代码，这样您就不会遇到这些限制。
You can start the browser up with the flag --allow-file-access-from-fileswhich removes the restriction.
您可以使用--allow-file-access-from-files取消限制的标志启动浏览器。
回答by Rocket Hazmat
For security reasons, you cannot make AJAX calls to your local file system. Some browsers allow this, but others don't. Chrome has a flag that enables this, but it's off by default.
出于安全原因，您不能对本地文件系统进行 AJAX 调用。一些浏览器允许这样做，但其他浏览器不允许。Chrome 有一个启用此功能的标志，但默认情况下它处于关闭状态。
回答by Christoph
Take a look into Same Origin Policy.
查看同源策略。
You cannot load the file because technically it is located in another domain. You need to call it like localhost/<Path>/nodesData.json.
您无法加载该文件，因为从技术上讲它位于另一个域中。你需要像localhost/<Path>/nodesData.json.
