javascript 未捕获的类型错误：无法读取 chrome 扩展中未定义的属性“本地”
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Uncaught TypeError: Cannot read property 'local' of undefined in chrome extension
提问by Milind Anantwar
I have written a Chrome extension. I cannot use
localStorage.setItemand localStorage.getItemfor storing and retrieving because background and browser action runs in different environment [as seen here].
我写了一个 Chrome 扩展。我无法使用
localStorage.setItem和localStorage.getItem进行存储和检索，因为后台和浏览器操作在不同的环境中运行 [如此处所见]。
So I decided to use the Chrome storage API:
所以我决定使用 Chrome 存储 API：
var storage = chrome.storage.local;
var myTestVar = 'somevar';
var obj = {};
obj[myTestVar] = $("#somevar").val();
storage.set(obj);
which produced the following error:
这产生了以下错误：
Uncaught TypeError: Cannot read property 'local' of undefined
未捕获的类型错误：无法读取未定义的属性“本地”
What am I doing wrong?
我究竟做错了什么？
回答by Rob W
Make sure that all necessary permissionshave been declared in the manifest file. "storage", in your case.
确保在清单文件中声明了所有必要的权限。"storage"，在你的情况下。
In general, the following steps should fix the problem of apparently undefined Chrome APIs:
一般来说，以下步骤应该可以解决明显未定义的 Chrome API 的问题：
- Read the documentation of the API you're using and get yourself familiar with the prerequisites, usually manifest permissions (e.g.
chrome.storage#manifest). - Check if your (user's) Chrome version supports the API, by looking at What's new.
- Check if the script is running in the right context. Most APIs are only available to the extension's process. (the
chrome.storageAPI can also be used in content script though) - Otherwise, resort to your usual debugging skills: Typos, variable shadowing, ...
- 阅读您正在使用的 API 的文档并熟悉先决条件，通常是清单权限（例如
chrome.storage#manifest）。 - 通过查看What's new 来检查您（用户的）Chrome 版本是否支持该 API 。
- 检查脚本是否在正确的上下文中运行。大多数 API 仅可用于扩展进程。（
chrome.storageAPI 也可以在内容脚本中使用） - 否则，请使用您通常的调试技巧：错别字、变量阴影、...
