Question

我认为chrome.storage API（here）的文档目前尚不清楚。我正在使用此代码添加一个监听器：

chrome.storage.onChanged.addListener(function(changes, namespace) {
    for (key in changes) {
      var storageChange = changes[key];
      console.log('Storage key "%s" in namespace "%s" changed. ' +
                  'Old value was "%s", new value is "%s".',
                  key,
                  namespace,
                  storageChange.oldValue,
                  storageChange.newValue);
    }
  });

但是如何删除这个监听器呢？如何使用chrome.storage.onChanged.removeListener()方法？

Answer 1

chrome.storage.onChanged.removeListener将您添加的侦听器函数作为输入，因此要在以后删除它，您必须将该函数存储在变量中。以下代码将起作用：

var myListenerFunction = function(changes, namespace) {
    for (key in changes) {
      var storageChange = changes[key];
      console.log('Storage key "%s" in namespace "%s" changed. ' +
                  'Old value was "%s", new value is "%s".',
                  key,
                  namespace,
                  storageChange.oldValue,
                  storageChange.newValue);
    }
};

// Add listener
chrome.storage.onChanged.addListener(myListenerFunction);

// Change value, will show output in console.log
chrome.storage.sync.set({'value': 'asd'});

// Remove listener
chrome.storage.onChanged.removeListener(myListenerFunction);

// Change value, will NOT show output in console.log as listener was removed
chrome.storage.sync.set({'value': 'asd123'});

其他阅读 - Chrome扩展程序规范的事件部分 - https://developer.chrome.com/extensions/events

Answer 2

我在您提供的页面中没有看到chrome.storage.onChanged.removeListener。

您可以尝试将回调函数分配给变量并将其传递给AddListener。然后用它来删除

＆＃13;

var changeListener = function(changes, namespace) {
    for (key in changes) {
      var storageChange = changes[key];
      console.log('Storage key "%s" in namespace "%s" changed. ' +
                  'Old value was "%s", new value is "%s".',
                  key,
                  namespace,
                  storageChange.oldValue,
                  storageChange.newValue);
    }
 };


chrome.storage.onChanged.removeListener(changeListner);

＆＃13;

如何删除chrome.storage.onChanged事件监听器？

2 个答案: