由网友(向日葵沒了太陽要如何微笑)分享简介：我试图让一个jQuery 阿贾克斯（）打电话公共Web服务，而且我无法找到正确的语法。 I'm trying to make a jQuery .ajax() call to a public web service, and I'm having trouble finding the right syntax....

我试图让一个jQuery 阿贾克斯（）打电话公共Web服务，而且我无法找到正确的语法。

I'm trying to make a jQuery .ajax() call to a public web service, and I'm having trouble finding the right syntax.

我已经尝试了几种不同的实现。这其中：

I've tried several different implementations. This one:

$.ajax({
  url: 'http://www.geognos.com/api/en/countries/info/all.jsonp',
  dataType: "jsonp",
  success: function() {
    alert('JSONP call succeeded!');
  }
});

它失败，出现以下错误：

It fails with the following error:

all.jsonp:1 Uncaught ReferenceError: callback is not defined

和这一个：

$.ajax({
  url: 'http://www.geognos.com/api/en/countries/info/all.json',
  dataType: "json",
  success: function() {
    alert('JSON call succeeded!');
  }
});

与此错误失败：

Fails with this error:

XMLHttpRequest cannot load http://www.geognos.com/api/en/countries/info/all.json. Origin http://localhost:8888 is not allowed by Access-Control-Allow-Origin.

我通过我的本地IIS7的情况下提供该页面。我也试过 $的各种组合。的getJSON（）类似的结果。我在想什么？

I'm serving the page through my local IIS7 instance. I've also tried various combinations of $.getJSON() with similar results. What am I missing?

下面是上述code进行的jsfiddle 。

更新：认为我们有一个解决方案，但我仍然得到回调没有定义错误时做JSONP调用，即使警报/日志code被调用。响应URL看起来是这样的：

UPDATE: Thought we had a solution, but I'm still getting the callback is not defined error when doing the JSONP calls, even though the alert/log code gets called. The response URL looks like this:

http://www.geognos.com/api/en/countries/info/all.jsonp?callback=undefined&157148585

和JSON响应被包裹这样的：

and the JSON response is wrapped like this:

callback({"StatusMsg": "OK", "Results": {"BD": {"Name": "Bangladesh", "Capital": {"DLST": "null", "TD": 6.0, "Flg": 2, "Name": "Dhaka", ...

我发现有添加到URL的末尾，在阿贾克斯（）配置回调名字的例子，但是当我尝试，我得到了相同的因此，只有它上涨到我的查询字符串的结尾。

I've found examples with the callback name added on to the end of the URL in the .ajax() configuration, but when I try that I get the same result, only it's tacked on to the end of my query string.

推荐答案

由于同源策略的这个正JSON调用将无法正常工作。这是你的错误是在告诉你：不受访问控制 - 允许 - 原产地允许

This regular JSON call will not work because of same origin policy. This is what your error is telling you with: is not allowed by Access-Control-Allow-Origin.

正确的JSONP语法是：

$.ajax({
    url: 'http://www.geognos.com/api/en/countries/info/all.jsonp',
    dataType: "jsonp",
    jsonpCallback: 'callback',
    success: function(data) {
        console.log(data);
    }
});

DEMO