Cod*_*lla 6 javascript google-chrome sendmessage google-chrome-extension
我正在制作我的第一个 chrome 扩展,并注意到从我的 popup.html 页面发送的消息在我的 content.js 消息事件侦听器中被复制。我在每条消息发送之前控制台记录了“发送消息”,在每条消息之前记录了“消息接收”,我不明白这些消息是如何被复制的。我还检查了sendMessage和onMessage的 chrome 开发文档,它指定 onMessage 侦听器应该只在每个 sendMessage 事件触发一次。
任何帮助,将不胜感激。
弹出窗口.html
<!DOCTYPE html>
<html>
<head>
<title>Messaging Practice</title>
</head>
<body>
<h1>Messaging Practice</h1>
<input type="button" id="send-message" value="Button">
<script src="popup.js"></script>
</body>
</html>
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内容.js
chrome.runtime.onMessage.addListener(
function(request, sender, sendResponse) {
console.log('message received')
console.log(request);
}
);
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弹出窗口.js
var messageButton = document.querySelector("#send-message");
messageButton.onclick = function() {
chrome.tabs.query({currentWindow: true, active: true},
function(tabs) {
chrome.tabs.executeScript(
tabs[0].id, {file: "content.js"}
)
console.log("sending message")
chrome.tabs.sendMessage(tabs[0].id, "string message")
});
}
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背景.js
chrome.declarativeContent.onPageChanged.removeRules(undefined, function() {
chrome.declarativeContent.onPageChanged.addRules([{
conditions: [new chrome.declarativeContent.PageStateMatcher({
pageUrl: {hostEquals: 'stackoverflow.com'},
})],
actions: [new chrome.declarativeContent.ShowPageAction()]
}]);
});
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清单文件
{
"name": "Send Messages Practice",
"version": "1.0",
"manifest_version": 2,
"description": "Simple messaging practice with the chrome api",
"permissions": ["declarativeContent", "activeTab"],
"background": {
"scripts": ["background.js"],
"persistant": true
},
"page_action": {
"default_popup": "popup.html",
"scripts": ["content.js"],
"matches": ["http://*/*","https://*/*"]
}
}
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小智 4
添加“返回 true;” 事件处理程序将阻止您的代码一次又一次触发:
chrome.runtime.onMessage.addListener(function (request, sender, sendResponse) {
if (request.action == "show_alert") {
alert(request.alert);
return true;
}
});
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