javascript - 尝试将消息传递到background.js时收到错误:

Question

extensions::uncaught_exception_handler:8 事件处理程序中出现错误(未知):TypeError: 无法读取未定义的属性“告别”

背景.js:

chrome.runtime.onMessage.addListener(function(message,sender,sendResponse){
if(message[message.length - 1] === true)
    {
        var AFArray = message; 
        sendResponse({farewell: AFArray});
    }
if(message === "request")
    {

        sendResponse({farewell:"TEsting!"});
    }});

内容脚本:

function AFCopy()
{
    var AFArrayCount = 0;
    var AFArray = [];
    //cycle over classes and apply label to array.
     while(AFArrayCount <4)
         {
             if(document.getElementsByClassName("_xd6")[AFArrayCount])
                 {
                     AFArray[AFArrayCount] = document.getElementsByClassName("_xd6")[AFArrayCount].getAttribute("LABEL"); 

                     AFArrayCount++;
                 }

         }
    //assign copy signature 
    AFArray.push(true);
    //test array is constructed correctly
    console.log(AFArray);

    //send array to background.js
    chrome.runtime.sendMessage({greeting: AFArray}, function(response) {
    console.log(response.farewell);});
} 

该函数在 onClick 事件上运行。

Answer 1

您发送的消息是:{greeting:AFArray}，该对象是您的监听器接收的内容。

因此 message[message.length - 1] 没有什么意义。

它应该类似于message.greeting[message.greeting.length - 1]