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對不起,這可能是一個非常不好的問題,可能已經被問到了。然而,我找不到回答我的具體問題的帖子,所以我仍然在那裏問。爲什麼我無法在cordova中訪問全局JS變量?
請注意,我完全是JavaScript的新手,我來自面向對象的編程語言。在回答時請保持在明!
我想讓我的科爾多瓦應用程序連接到websocket服務器。由於我的應用程序只適用於Android 4.4及以上版本,我想出了使用javascript的window.WebSocket對象是一個好主意。因此,我創建一個像這樣的「全局」變量:
var socket = null;
var app = {
initialize: function() {
document.addEventListener('deviceready', this.onDeviceReady.bind(this), false);
...
}
我可以使用下面的代碼成功地創建的WebSocket對象:
websocketSetup: function() {
var serverUrl = "ws://echo.websocket.org";
var logdiv = document.getElementById("logs");
//Called when the client opents the conection to the server
var onOpen = function() {
logdiv.innerHTML += "<p class='purple'>Websocket opened: " + serverUrl + "</p>";
socket.send("Hello");//FIXME: remove this line
};
//Called when the client or the server drops the connection, or sends a close request
var onClose = function() {
logdiv.innerHTML += "<p class='purple'>Websocket closed.</p>";
socket = null;
};
//Called when the client recieves a request from the server
var onMessage = function(event) {
logdiv.innerHTML += "<p class='purple'>Message:" + event.data + "</p>";
};
//Called from the client websocket implementation when an error happens
var onError = function(event) {
logdiv.innerHTML += "<p class='purple'>" + event.data + "</p>";
};
try{
socket = new WebSocket("ws://echo.websocket.org");
socket.onopen = onOpen;
socket.onclose = onClose;
socket.onmessage = onMessage;
socket.onerror = onError;
}catch(e){
logdiv.innerHTML += "<p class='red'>" + e + "</p>";
}
},
這一切正常,我成功地從回聲獲得回聲websocket服務器。 但是,我無法再訪問此套接字變量了。功能,如:
socketMessage: function(outgoingmessage) {
socket.send(outgoingmessage);
var logdiv = document.getElementById("logs");
logdiv.innerHTML += "<p class='purple'>Message sent to WS:" + outgoingmessage + "</p>";
}
根本不起作用,只要我指的是插座變量,函數停止它的執行。它也不會拋出我可以嘗試/捕捉的異常。
感謝您的幫助!