python GUI库图形界面开发之PyQt5中QWebEngineView内嵌网页与Python的数据交互传参详细方法实例

python GUI库图形界面开发之PyQt5中QWebEngineView内嵌网页与Python的数据交互传参详细方法实例

这几天研究了下PyQt5中QWebEngineView内嵌网页与Python的数据交互，今天把实例方法与代码发布出来供大家参数

数据交互需要load进一个网页，这里我选择load进一个本地html网页：JSTest.html。

同时，QWebEngineView与外面的交互还需要Qt官方提供的一个js文件：qwebchannel.js，这个文件可以在网上下载。

JSTest.html和qwebchannel.js两个文件放在同一个目录下，我这边都是放在Python工程目录下。

qwebchannel.js：

"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 < response.length; ++i) {
 ret[i] = object.unwrapQObject(response[i]);
      }
      return ret;
    }
    if (!response
      || !response["__QObject*__"]
      || response.id === undefined) {
      return response;
    }
 
    var objectId = response.id;
    if (webChannel.objects[objectId])
      return webChannel.objects[objectId];
 
    if (!response.data) {
      console.error("Cannot unwrap unknown QObject " + objectId + " without data.");
      return;
    }
 
    var qObject = new QObject( objectId, response.data, webChannel );
    qObject.destroyed.connect(function() {
      if (webChannel.objects[objectId] === qObject) {
 delete webChannel.objects[objectId];
 // reset the now deleted QObject to an empty {} object
 // just assigning {} though would not have the desired effect, but the
 // below also ensures all external references will see the empty map
 // NOTE: this detour is necessary to workaround QTBUG-40021
 var propertyNames = [];
 for (var propertyName in qObject) {
   propertyNames.push(propertyName);
 }
 for (var idx in propertyNames) {
   delete qObject[propertyNames[idx]];
 }
      }
    });
    // here we are already initialized, and thus must directly unwrap the properties
    qObject.unwrapProperties();
    return qObject;
  }
 
  this.unwrapProperties = function()
  {
    for (var propertyIdx in object.__propertyCache__) {
      object.__propertyCache__[propertyIdx] = object.unwrapQObject(object.__propertyCache__[propertyIdx]);
    }
  }
 
  function addSignal(signalData, isPropertyNotifySignal)
  {
    var signalName = signalData[0];
    var signalIndex = signalData[1];
    object[signalName] = {
      connect: function(callback) {
 if (typeof(callback) !== "function") {
   console.error("Bad callback given to connect to signal " + signalName);
   return;
 }
 
 object.__objectSignals__[signalIndex] = object.__objectSignals__[signalIndex] || [];
 object.__objectSignals__[signalIndex].push(callback);
 
 if (!isPropertyNotifySignal && signalName !== "destroyed") {
   // only required for "pure" signals, handled separately for properties in propertyUpdate
   // also note that we always get notified about the destroyed signal
   webChannel.exec({
     type: QWebChannelMessageTypes.connectToSignal,
     object: object.__id__,
     signal: signalIndex
   });
 }
      },
      disconnect: function(callback) {
 if (typeof(callback) !== "function") {
   console.error("Bad callback given to disconnect from signal " + signalName);
   return;
 }
 object.__objectSignals__[signalIndex] = object.__objectSignals__[signalIndex] || [];
 var idx = object.__objectSignals__[signalIndex].indexOf(callback);
 if (idx === -1) {
   console.error("Cannot find connection of signal " + signalName + " to " + callback.name);
   return;
 }
 object.__objectSignals__[signalIndex].splice(idx, 1);
 if (!isPropertyNotifySignal && object.__objectSignals__[signalIndex].length === 0) {
   // only required for "pure" signals, handled separately for properties in propertyUpdate
   webChannel.exec({
     type: QWebChannelMessageTypes.disconnectFromSignal,
     object: object.__id__,
     signal: signalIndex
   });
 }
      }
    };
  }
 
  
  function invokeSignalCallbacks(signalName, signalArgs)
  {
    var connections = object.__objectSignals__[signalName];
    if (connections) {
      connections.forEach(function(callback) {
 callback.apply(callback, signalArgs);
      });
    }
  }
 
  this.propertyUpdate = function(signals, propertyMap)
  {
    // update property cache
    for (var propertyIndex in propertyMap) {
      var propertyValue = propertyMap[propertyIndex];
      object.__propertyCache__[propertyIndex] = propertyValue;
    }
 
    for (var signalName in signals) {
      // Invoke all callbacks, as signalEmitted() does not. This ensures the
      // property cache is updated before the callbacks are invoked.
      invokeSignalCallbacks(signalName, signals[signalName]);
    }
  }
 
  this.signalEmitted = function(signalName, signalArgs)
  {
    invokeSignalCallbacks(signalName, signalArgs);
  }
 
  function addMethod(methodData)
  {
    var methodName = methodData[0];
    var methodIdx = methodData[1];
    object[methodName] = function() {
      var args = [];
      var callback;
      for (var i = 0; i < arguments.length; ++i) {
 if (typeof arguments[i] === "function")
   callback = arguments[i];
 else
   args.push(arguments[i]);
      }
 
      webChannel.exec({
 "type": QWebChannelMessageTypes.invokeMethod,
 "object": object.__id__,
 "method": methodIdx,
 "args": args
      }, function(response) {
 if (response !== undefined) {
   var result = object.unwrapQObject(response);
   if (callback) {
     (callback)(result);
   }
 }
      });
    };
  }
 
  function bindGetterSetter(propertyInfo)
  {
    var propertyIndex = propertyInfo[0];
    var propertyName = propertyInfo[1];
    var notifySignalData = propertyInfo[2];
    // initialize property cache with current value
    // NOTE: if this is an object, it is not directly unwrapped as it might
    // reference other QObject that we do not know yet
    object.__propertyCache__[propertyIndex] = propertyInfo[3];
 
    if (notifySignalData) {
      if (notifySignalData[0] === 1) {
 // signal name is optimized away, reconstruct the actual name
 notifySignalData[0] = propertyName + "Changed";
      }
      addSignal(notifySignalData, true);
    }
 
    Object.defineProperty(object, propertyName, {
      configurable: true,
      get: function () {
 var propertyValue = object.__propertyCache__[propertyIndex];
 if (propertyValue === undefined) {
   // This shouldn't happen
   console.warn("Undefined value in property cache for property "" + propertyName + "" in object " + object.__id__);
 }
 
 return propertyValue;
      },
      set: function(value) {
 if (value === undefined) {
   console.warn("Property setter for " + propertyName + " called with undefined value!");
   return;
 }
 object.__propertyCache__[propertyIndex] = value;
 webChannel.exec({
   "type": QWebChannelMessageTypes.setProperty,
   "object": object.__id__,
   "property": propertyIndex,
   "value": value
 });
      }
    });
 
  }
 
  // ----------------------------------------------------------------------
 
  data.methods.forEach(addMethod);
 
  data.properties.forEach(bindGetterSetter);
 
  data.signals.forEach(function(signal) { addSignal(signal, false); });
 
  for (var name in data.enums) {
    object[name] = data.enums[name];
  }
}
 
//required for use with nodejs
if (typeof module === 'object') {
  module.exports = {
    QWebChannel: QWebChannel
  };
}

Python主函数代码

import sys
import Web_UI
from PyQt5 import QtCore, QtGui, QtWidgets
from PyQt5.QtCore import QObject,pyqtProperty
from PyQt5.QtWebChannel import QWebChannel
from MySharedObject import MySharedObject
from PyQt5.QtWidgets import QApplication
import os

base_DIR = os.path.dirname(__file__)#获取当前文件夹的绝对路径

if __name__ == '__main__':
  app = QtWidgets.QApplication(sys.argv)
  MainWindow = QtWidgets.Qframe()
  ui = Web_UI.Ui_Form()
  ui.setupUi(MainWindow)
  ui.webView1.load(QtCore.QUrl(r""+base_DIR+"/JSTest.html"))

  channel = QWebChannel() ##创建一个QwebChannel对象，用于传递PyQt的参数到Javascript
  myObj = MySharedObject()
  print(myObj.strval)

  channel.registerObject('bridge', myObj)
  ui.webView1.page().setWebChannel(channel)

  MainWindow.show()
  sys.exit(app.exec_())

继承了QWidget类的MySharedObject(Python文件)

from PyQt5.QtCore import QObject
from PyQt5.QtCore import pyqtProperty
from PyQt5.QtWidgets import QWidget,QMessageBox

class MySharedObject(QWidget):
  def __init__(self,strval = '100'):
    super(MySharedObject,self).__init__()
    self.strval = strval
  def _getStrValue(self):
    return self.strval
  def _setStrValue(self,str):
    self.strval = str
    print('获得页面参数：%s'% str)
    QMessageBox.information(self,"Infomation", '获得的页面参数%s' % str)
  #需要定义的对外发布的方法
  strValue= pyqtProperty(str,_getStrValue,_setStrValue)

页面代码HTML

实现效果

本文详细介绍了PyQt5中使用QWebEngineView控件内嵌网页与Python的数据交互的方法与实例，更多关于这方面的知识请查看下面的相关链接