Sends a single message to event listeners within your extension or a different extension.
If sending to your extension, omit the
extensionId
自变量。
runtime.onMessage
event will be fired in each page in your extension, except for the frame that called
runtime.sendMessage
.
If sending to a different extension, include the
extensionId
argument set to the other extension's ID.
runtime.onMessageExternal
will be fired in the other extension.
Extensions cannot send messages to content scripts using this method. To send messages to content scripts, use
tabs.sendMessage
.
This is an asynchronous function that returns a
Promise
.
注意： You can also use a connection-based approach to exchange messages .
var sending = browser.runtime.sendMessage(
extensionId, // optional string
message, // any
options // optional object
)
extensionId
可选
string
. The ID of the extension to send the message to. Include this to send the message to a different extension. If the intended recipient has set an ID explicitly using the
应用程序
key in manifest.json, then
extensionId
should have that value. Otherwise it should have the ID that was generated for the intended recipient.
若
extensionId
is omitted, the message will be sent to your own extension.
message
any
. An object that can be structured clone serialized (see
Data cloning algorithm
).
选项
可选
对象
.
includeTlsChannelId
可选
boolean
. Whether the TLS channel ID will be passed into
runtime.onMessageExternal
for processes that are listening for the connection event.
This option is only supported in Chromium-based browsers.
Depending on the arguments it is given, this API is sometimes ambiguous. The following rules are used:
(message, options)
, and the message is sent internally, if the second argument is any of the following:
选项
object (meaning, it is an object which contains only the properties of
选项
that the browser supports)
(extensionId, message)
. The message will be sent to the extension identified by
extensionId
.
(extensionId, message, options)
. The message will be sent to the extension identified by
extensionId
.
Note that before Firefox 55, the rules were different in the 2-argument case. Under the old rules, if the first argument was a string, it was treated as the
extensionId
, with the message as the second argument. This meant that if you called
sendMessage()
with arguments like
("my-message", {})
, then it would send an empty message to the extension identified by "my-message". Under the new rules, with these arguments you would send the message "my-message" internally, with an empty options object.
A
Promise
. If the receiver sent a response, this will be fulfilled with the response. Otherwise it will be fulfilled with no arguments. If an error occurs while connecting to the extension, the promise will be rejected with an error message.
BCD tables only load in the browser
Here's a content script that sends a message to the background script when the user clicks the content window. The message payload is
{greeting: "Greeting from the content script"}
, and the sender also expects to get a response, which is handled in the
handleResponse
函数：
// content-script.js
function handleResponse(message) {
console.log(`Message from the background script: ${message.response}`);
}
function handleError(error) {
console.log(`Error: ${error}`);
}
function notifyBackgroundPage(e) {
var sending = browser.runtime.sendMessage({
greeting: "Greeting from the content script"
});
sending.then(handleResponse, handleError);
}
window.addEventListener("click", notifyBackgroundPage);
The corresponding background script looks like this:
// background-script.js
function handleMessage(request, sender, sendResponse) {
console.log("Message from the content script: " +
request.greeting);
sendResponse({response: "Response from background script"});
}
browser.runtime.onMessage.addListener(handleMessage);
注意：
Instead of using
sendResponse()
，返回
Promise
is the recommended approach for Firefox add-ons.
Examples using a Promise are available in the
examples section
的
runtime.onMessage
listener.
注意：
This API is based on Chromium's
chrome.runtime
API. This documentation is derived from
runtime.json
in the Chromium code.
Microsoft Edge compatibility data is supplied by Microsoft Corporation and is included here under the Creative Commons Attribution 3.0 United States License.
最后修改： , 由 MDN 贡献者