我希望完成与原始帖子相同的事情,并且能够通过一些消息传递使其工作。不管这是否是不好的做法,我都使用了 enabled(true/false) contextMenu 属性来保留我的上下文菜单选项,但显示为灰色。
我创建了一个上下文菜单。重要的属性是 id。其余的大部分都是任意的,因为它将动态更改。
在 content.js 中
//This event listener will determine if the context menu should be updated
//based on if the right-button was clicked and if there is a selection or not
document.addEventListener("mousedown", function(event){
if (event.button !== 2) {
return false;
}
var selected = window.getSelection().toString();
if(event.button == 2 && selected != '') {
//get selected text and send request to bkgd page to create menu
chrome.extension.sendMessage({
'message': 'updateContextMenu',
'selection': true});
} else {
chrome.extension.sendMessage({
'message': 'updateContextMenu',
'selection': false});
}
}, true);
在 background.js 中:
//add a message listener that will modify the context menu however you see fit
chrome.extension.onMessage.addListener(function(request, sender, sendResponse) {
if (request.message == 'updateContextMenu') {
if (request.selection) {
chrome.contextMenus.update('contextMenuId',{
'title': 'New Title',
'enabled': true,
"contexts": ["all"],
'onclick': someFunction
});
} else {
chrome.contextMenus.update('contextMenuId',{
'title': 'Select some text first',
'enabled': false,
"contexts": ["all"]
});
}
} else {
sendResponse({});
}
});
//The original context menu. The important property is the id. The rest is mostly
//arbitrary because it will be changed dynamically by the listener above.
chrome.contextMenus.create({
'id': 'contextMenuId',
'enabled': false,
'title': 'Some Title',
"contexts": ["all"]
});