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文章目录
前言一、开发环境二、开发步骤1.HTML开发1.1 qwebchannel.js1.2 sample.html这里是我用太乐地图生成的离线版本，然后自己修改生成的代码
2.QT开发
总结
前言
本文介绍了关于利用QWebchannel与百度地图进行交互传递经纬度坐标数据
以下是我参考其他人代码实现的分享以下
一、开发环境
使用的是QT5.14.2 + MSVC2017 64/32bit +win10 （MinGW默认不支持 QWebEngineView）关于怎么使用MSVC可以参考我之前的博客 QT5.14搭建MSVC(VS2017) x86 以及64位编译器开发环境搭建（GDB配置） 
二、开发步骤
1.HTML开发
1.1 qwebchannel.js
代码如下（示例）：首先在外面加入qwebchannel.js 在HTML所在的目录添加qwebchannel.js这里因为我是利用太乐地图下载的离线地图，所以会有这么多文件，如果是直接联网获取地图数据，只需要在其HTML根目录添加一个这个即可，关于怎么利用太乐地图下载地图数据我回头抽空下一篇文章写一下。加下来我放了离线跟在线地图的HTML大家自己参考  下面是qwebchannel.js中代码
"use strict";
var QWebChannelMessageTypes = {
signal: 1,
propertyUpdate: 2,
init: 3,
idle: 4,
debug: 5,
invokeMethod: 6,
connectToSignal: 7,
disconnectFromSignal: 8,
setProperty: 9,
response: 10,
};
var QWebChannel = function(transport, initCallback)
{
if (typeof transport !== "object" || typeof transport.send !== "function") {
console.error("The QWebChannel expects a transport object with a send function and onmessage callback property." +
" Given is: transport: " + typeof(transport) + ", transport.send: " + typeof(transport.send));
return;
}
var channel = this;
this.transport = transport;
this.send = function(data)
{
if (typeof(data) !== "string") {
data = JSON.stringify(data);
}
channel.transport.send(data);
}
this.transport.onmessage = function(message)
{
var data = message.data;
if (typeof data === "string") {
data = JSON.parse(data);
}
switch (data.type) {
case QWebChannelMessageTypes.signal:
channel.handleSignal(data);
break;
case QWebChannelMessageTypes.response:
channel.handleResponse(data);
break;
case QWebChannelMessageTypes.propertyUpdate:
channel.handlePropertyUpdate(data);
break;
default:
console.error("invalid message received:", message.data);
break;
}
}
this.execCallbacks = {};
this.execId = 0;
this.exec = function(data, callback)
{
if (!callback) {
// if no callback is given, send directly
channel.send(data);
return;
}
if (channel.execId === Number.MAX_VALUE) {
// wrap
channel.execId = Number.MIN_VALUE;
}
if (data.hasOwnProperty("id")) {
console.error("Cannot exec message with property id: " + JSON.stringify(data));
return;
}
data.id = channel.execId++;
channel.execCallbacks[data.id] = callback;
channel.send(data);
};
this.objects = {};
this.handleSignal = function(message)
{
var object = channel.objects[message.object];
if (object) {
object.signalEmitted(message.signal, message.args);
} else {
console.warn("Unhandled signal: " + message.object + "::" + message.signal);
}
}
this.handleResponse = function(message)
{
if (!message.hasOwnProperty("id")) {
console.error("Invalid response message received: ", JSON.stringify(message));
return;
}
channel.execCallbacks[message.id](message.data);
delete channel.execCallbacks[message.id];
}
this.handlePropertyUpdate = function(message)
{
for (var i in message.data) {
var data = message.data[i];
var object = channel.objects[data.object];
if (object) {
object.propertyUpdate(data.signals, data.properties);
} else {
console.warn("Unhandled property update: " + data.object + "::" + data.signal);
}
}
channel.exec({type: QWebChannelMessageTypes.idle});
}
this.debug = function(message)
{
channel.send({type: QWebChannelMessageTypes.debug, data: message});
};
channel.exec({type: QWebChannelMessageTypes.init}, function(data) {
for (var objectName in data) {
var object = new QObject(objectName, data[objectName], channel);
}
// now unwrap properties, which might reference other registered objects
for (var objectName in channel.objects) {
channel.objects[objectName].unwrapProperties();
}
if (initCallback) {
initCallback(channel);
}
channel.exec({type: QWebChannelMessageTypes.idle});
});
};
function QObject(name, data, webChannel)
{
this.__id__ = name;
webChannel.objects[name] = this;
// List of callbacks that get invoked upon signal emission
this.__objectSignals__ = {};
// Cache of all properties, updated when a notify signal is emitted
this.__propertyCache__ = {};
var object = this;
// ----------------------------------------------------------------------
this.unwrapQObject = function(response)
{
if (response instanceof Array) {
// support list of objects
var ret = new Array(response.length);
for (var i = 0; i |