javascript 如何从 Rest API 获取 JSON 数据
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How do I get JSON data from Rest APi
提问by InfoLearner
I am creating an object in javascript:
我正在用 javascript 创建一个对象：
var t = null;
$.getJSON('http://localhost:53227/Home/GetData', function (data) {
alert(data);
t = data;
});
alert(t);
When I alert data, I get an object back. When I alert t, it's null.
当我提醒数据时，我会返回一个对象。当我提醒 t 时，它为空。
Can you please guide, how to set "t" to the returned data?
你能指导一下，如何将“t”设置为返回的数据？
回答by Madbreaks
This will work as expected - the issue is not that tis not set, it's that you're doing alert(t)before the getJSONcallback is executed. Try doing alert(t)immediately after t = data;
这将按预期工作 - 问题不是t未设置，而是您在执行回调alert(t)之前getJSON正在执行的操作。尝试alert(t)后立即执行t = data;
In other words, here's your current order of operations:
换句话说，这是您当前的操作顺序：
- Set t = null
- Call server script
- alert(t) --> t is still null!
- (some amount of time later) receive JSON response
- alert data
- set t = data
- 设置 t = null
- 调用服务器脚本
- alert(t) --> t 仍然为空！
- （一段时间后）接收 JSON 响应
- 警报数据
- 设置 t = 数据
...as you can see, at step 3 't' will still be null. Try this instead:
...如您所见，在第 3 步 't' 仍将为空。试试这个：
var t = null;
$.getJSON('http://localhost:53227/Home/GetData', function (data) {
alert(data);
t = data;
alert(t);
});
Cheers
干杯
