Chrome扩展消息传递：sendResponse返回空对象

Z时代
2024-01-10
分类：问答

我正在构建Chrome扩展，并且希望在用户单击上下文菜单后获取当前选定的文本。我试图通过从后台脚本向内容脚本发送消息来做到这一点，但从内容脚本返回的对象始终为空。Chrome扩展消息传递：sendResponse返回空对象

下面是相关代码：

background_script.js：

function onClickHandler(info, tab){ 
    chrome.tabs.query({active: true, currentWindow: true}, function(tabs) { 
     chrome.tabs.sendMessage(tabs[0].id, {method: "getSelection"}, undefined, function(response){ 
      console.log(response.data); // <--- this is undefined 
     }); 
    }); 
} 
chrome.contextMenus.onClicked.addListener(onClickHandler);

content_script.js：

chrome.runtime.onMessage.addListener( 
    function(request, sender, sendResponse) { 
     if (request.method == "getSelection"){ 
      var selection = window.getSelection(); // <--- this is ok 
      sendResponse({data: selection}); 
      return true; 
     } 
    } 
)

的manifest.json

{ 
    "manifest_version": 2, 
    "name": "Browser Extension", 
    "description": "Browser Extension", 
    "version": "0.1", 
    "background": { 
     "scripts": [ 
      "background_script.js" 
     ] 
    }, 
    "content_scripts": [ 
     { 
      "matches": ["<all_urls>"], 
      "js": ["content_script.js"] 
     } 
    ], 
    "permissions": [ 
     "activeTab", 
     "contextMenus", 
     "storage" 
    ] 
}