如何使用setTimeout监听来自window.postMessage的消息？

Question

How can I listen to the messages coming from window.postMessage only for amount of time?

I tried to use setTimeout inside the the event listener's function but this doesn't work.

My try:

function processMessages(message) {
//setTimeout(function() {
    if (message) {
        console.log("you have a message");
    } else {
        console.log("no messages came"); //<=== I can't get here!
    }
//},10000);
    window.removeEventListener("message", processMessages, false);
}

window.addEventListener("message", processMessages, false);

Answer 1

Rearrange your code to place .removeEventListener() call within setTimeout() , which does not need to be within processMessage function

function processMessages(message) {
    if (message) {
        console.log("you have a message");
    } else {
        console.log("no messages came"); //<=== I can't get here!
    }   
}

window.addEventListener("message", processMessages, false);

var timeout = setTimeout(function() {
                window.removeEventListener("message", processMessages, false);
              }, 10000);

Answer 2

您设置了setTimeout事件运行，但是消息的removeEventListener没有延迟。