如何使用 QWebChannel 将信息从 JS 传递到 Python
How to pass info from JS to Python using QWebChannel
我已经通过 PyQt5 在 Python 中构建了一个 GUI。我正在显示带有 google 地图页面的网络浏览器。用户应该移动标记,我的程序应该处理标记的坐标。因此我必须将坐标从 JS 传递到 Python,但我无法让它工作。
这是 HTML 文件:
<html>
<head>
<meta name="viewport" content="initial-scale=1.0, user-scalable=yes" />
<script type="text/javascript" src="http://maps.google.com/maps/api/js?sensor=false"></script>
<script type="text/javascript">
function geocodePosition(pos) {
geocoder.geocode({
latLng: pos
}, function(responses) {
if (responses && responses.length > 0) {
updateMarkerAddress(responses[0].formatted_address);
} else {
updateMarkerAddress('Cannot determine address at this location.');
}
});
}
function updateMarkerStatus(str) {
document.getElementById('markerStatus').innerHTML = str;
}
function updateMarkerPosition(latLng) {
document.getElementById('info').innerHTML = [
latLng.lat(),
latLng.lng()
].join(', ');
}
function updateMarkerAddress(str) {
document.getElementById('address').innerHTML = str;
}
var geocoder = new google.maps.Geocoder();
var map;
var goldStar = {
path: 'M 125,5 155,90 245,90 175,145 200,230 125,180 50,230 75,145 5,90 95,90 z',
fillColor: 'yellow',
fillOpacity: 0.8,
scale: 0.1,
strokeColor: 'gold',
strokeWeight: 1
};
function addMarker(lat, lon, city, url) {
var newmarker = new google.maps.Marker({
position: new google.maps.LatLng(lat, lon),
icon: goldStar,
map: map,
title: city
});
newmarker['infowindow'] = new google.maps.InfoWindow({
content: url
});
google.maps.event.addListener(newmarker, 'click', function() {
this['infowindow'].open(map, this);
});
}
function initialize() {
var latLng = new google.maps.LatLng(40.767367, -111.848007);
// create as a global variable
map = new google.maps.Map(document.getElementById('mapCanvas'), {
zoom: 11,
center: latLng,
mapTypeId: google.maps.MapTypeId.ROADMAP
});
var marker = new google.maps.Marker({
position: latLng,
title: 'Point A',
map: map,
draggable: true
});
// Update current position info.
updateMarkerPosition(latLng);
geocodePosition(latLng);
// Add dragging event listeners.
google.maps.event.addListener(marker, 'dragstart', function() {
updateMarkerAddress('Dragging...');
});
google.maps.event.addListener(marker, 'drag', function() {
updateMarkerStatus('Dragging...');
updateMarkerPosition(marker.getPosition());
});
google.maps.event.addListener(marker, 'dragend', function() {
updateMarkerStatus('Drag ended');
geocodePosition(marker.getPosition());
});
// return latLng
}
// Onload handler to fire off the app.
google.maps.event.addDomListener(window, 'load', initialize);
</script>
</head>
<body>
<style>
#mapCanvas {
# width: 1000px;
width: 102%;
height: 500px;
float: left;
margin-left: -7px;
margin-right: -10px;
margin-top: -7px;
margin-bottom: 10px;
}
#infoPanel {
float: center;
margin-left: 20px;
}
#infoPanel div {
margin-bottom: 10px;
}
</style>
<font size="3" color="black" face="verdana">
<div id="mapCanvas"></div>
<div id="infoPanel">
<font size="3" color="black" face="verdana">
<!-- <b>Marker status:</b> -->
<div id="markerStatus"><i>Click and drag the marker.</i></div>
<font size="3" color="black" face="verdana">
<b>Current position:</b>
<div id="info"></div>
<!--<b>Closest matching address:</b>-->
<!--<div id="address"></div>-->
</div>
</body>
</html>
这里是 Python 代码:
import sys
from PyQt5.QtWidgets import *
from GUI_tmy3 import *
class ShowMap_fun(QMainWindow):
def __init__(self):
super().__init__()
self.map_ui = Ui_tmy3page() # The name of my top level object is MainWindow
self.map_ui.setupUi(self)
self.map_ui.html_code.load(QtCore.QUrl.fromLocalFile('/Users/carlo/Dropbox/modules_NEW/useless.html'))
if __name__ == '__main__':
app = QApplication(sys.argv)
ex = ShowMap_fun()
ex.show()
sys.exit(app.exec_())
使用 GUI 代码:
from PyQt5 import QtCore, QtGui, QtWidgets
class Ui_tmy3page(object):
def setupUi(self, MainWindow):
MainWindow.setObjectName("MainWindow")
MainWindow.resize(900, 620)
MainWindow.setMinimumSize(QtCore.QSize(900, 620))
MainWindow.setMaximumSize(QtCore.QSize(900, 620))
MainWindow.setWindowTitle("")
self.centralwidget = QtWidgets.QWidget(MainWindow)
self.centralwidget.setObjectName("centralwidget")
self.html_code = QtWebEngineWidgets.QWebEngineView(self.centralwidget)
self.html_code.setGeometry(QtCore.QRect(0, 0, 901, 621))
self.html_code.setUrl(QtCore.QUrl("about:blank"))
self.html_code.setObjectName("html_code")
MainWindow.setCentralWidget(self.centralwidget)
self.retranslateUi(MainWindow)
QtCore.QMetaObject.connectSlotsByName(MainWindow)
def retranslateUi(self, MainWindow):
pass
from PyQt5 import QtWebEngineWidgets
我知道最简单的方法是使用 QWebChannel。我找到了一个示例 here,但我无法根据我的情况对其进行调整。
有什么建议吗?
为了使工作更有条理,我将 javascript 代码分离到一个名为 useless.js.
的新文件中
你应该做的是创建一个QWebChannel对象,在页面上设置它并注册这个对象,你还必须创建一个接收信息的slot:
class ShowMap_fun(QMainWindow):
def __init__(self):
super().__init__()
self.map_ui = Ui_tmy3page() # The name of my top level object is MainWindow
self.map_ui.setupUi(self)
channel = QtWebChannel.QWebChannel(self.map_ui.html_code.page())
self.map_ui.html_code.page().setWebChannel(channel)
channel.registerObject("jshelper", self)
self.map_ui.html_code.load(QtCore.QUrl.fromLocalFile(QtCore.QDir.current().filePath("useless.html")))
@QtCore.pyqtSlot(float, float)
def markerMoved(self, lat, lng):
print(lat, lng)
然后您必须将 qwebchannel.js
文件添加到 .html
useless.html
<html>
<head>
<meta name="viewport" content="initial-scale=1.0, user-scalable=yes"/>
<script type="text/javascript" src="./qwebchannel.js"></script>
<script type="text/javascript" src="http://maps.google.com/maps/api/js?sensor=false"></script>
<script type="text/javascript" src="useless.js"></script>
</head>
[...]
代码js中必须获取对象:
useless.js
var jshelper;
new QWebChannel(qt.webChannelTransport, function (channel) {
jshelper = channel.objects.jshelper;
});
[...]
google.maps.event.addListener(marker, 'drag', function () {
updateMarkerStatus('Dragging...');
updateMarkerPosition(marker.getPosition());
jshelper.markerMoved(marker.position.lat(), marker.position.lng());
});
完整的例子可以在下面找到link
我已经通过 PyQt5 在 Python 中构建了一个 GUI。我正在显示带有 google 地图页面的网络浏览器。用户应该移动标记,我的程序应该处理标记的坐标。因此我必须将坐标从 JS 传递到 Python,但我无法让它工作。
这是 HTML 文件:
<html>
<head>
<meta name="viewport" content="initial-scale=1.0, user-scalable=yes" />
<script type="text/javascript" src="http://maps.google.com/maps/api/js?sensor=false"></script>
<script type="text/javascript">
function geocodePosition(pos) {
geocoder.geocode({
latLng: pos
}, function(responses) {
if (responses && responses.length > 0) {
updateMarkerAddress(responses[0].formatted_address);
} else {
updateMarkerAddress('Cannot determine address at this location.');
}
});
}
function updateMarkerStatus(str) {
document.getElementById('markerStatus').innerHTML = str;
}
function updateMarkerPosition(latLng) {
document.getElementById('info').innerHTML = [
latLng.lat(),
latLng.lng()
].join(', ');
}
function updateMarkerAddress(str) {
document.getElementById('address').innerHTML = str;
}
var geocoder = new google.maps.Geocoder();
var map;
var goldStar = {
path: 'M 125,5 155,90 245,90 175,145 200,230 125,180 50,230 75,145 5,90 95,90 z',
fillColor: 'yellow',
fillOpacity: 0.8,
scale: 0.1,
strokeColor: 'gold',
strokeWeight: 1
};
function addMarker(lat, lon, city, url) {
var newmarker = new google.maps.Marker({
position: new google.maps.LatLng(lat, lon),
icon: goldStar,
map: map,
title: city
});
newmarker['infowindow'] = new google.maps.InfoWindow({
content: url
});
google.maps.event.addListener(newmarker, 'click', function() {
this['infowindow'].open(map, this);
});
}
function initialize() {
var latLng = new google.maps.LatLng(40.767367, -111.848007);
// create as a global variable
map = new google.maps.Map(document.getElementById('mapCanvas'), {
zoom: 11,
center: latLng,
mapTypeId: google.maps.MapTypeId.ROADMAP
});
var marker = new google.maps.Marker({
position: latLng,
title: 'Point A',
map: map,
draggable: true
});
// Update current position info.
updateMarkerPosition(latLng);
geocodePosition(latLng);
// Add dragging event listeners.
google.maps.event.addListener(marker, 'dragstart', function() {
updateMarkerAddress('Dragging...');
});
google.maps.event.addListener(marker, 'drag', function() {
updateMarkerStatus('Dragging...');
updateMarkerPosition(marker.getPosition());
});
google.maps.event.addListener(marker, 'dragend', function() {
updateMarkerStatus('Drag ended');
geocodePosition(marker.getPosition());
});
// return latLng
}
// Onload handler to fire off the app.
google.maps.event.addDomListener(window, 'load', initialize);
</script>
</head>
<body>
<style>
#mapCanvas {
# width: 1000px;
width: 102%;
height: 500px;
float: left;
margin-left: -7px;
margin-right: -10px;
margin-top: -7px;
margin-bottom: 10px;
}
#infoPanel {
float: center;
margin-left: 20px;
}
#infoPanel div {
margin-bottom: 10px;
}
</style>
<font size="3" color="black" face="verdana">
<div id="mapCanvas"></div>
<div id="infoPanel">
<font size="3" color="black" face="verdana">
<!-- <b>Marker status:</b> -->
<div id="markerStatus"><i>Click and drag the marker.</i></div>
<font size="3" color="black" face="verdana">
<b>Current position:</b>
<div id="info"></div>
<!--<b>Closest matching address:</b>-->
<!--<div id="address"></div>-->
</div>
</body>
</html>
这里是 Python 代码:
import sys
from PyQt5.QtWidgets import *
from GUI_tmy3 import *
class ShowMap_fun(QMainWindow):
def __init__(self):
super().__init__()
self.map_ui = Ui_tmy3page() # The name of my top level object is MainWindow
self.map_ui.setupUi(self)
self.map_ui.html_code.load(QtCore.QUrl.fromLocalFile('/Users/carlo/Dropbox/modules_NEW/useless.html'))
if __name__ == '__main__':
app = QApplication(sys.argv)
ex = ShowMap_fun()
ex.show()
sys.exit(app.exec_())
使用 GUI 代码:
from PyQt5 import QtCore, QtGui, QtWidgets
class Ui_tmy3page(object):
def setupUi(self, MainWindow):
MainWindow.setObjectName("MainWindow")
MainWindow.resize(900, 620)
MainWindow.setMinimumSize(QtCore.QSize(900, 620))
MainWindow.setMaximumSize(QtCore.QSize(900, 620))
MainWindow.setWindowTitle("")
self.centralwidget = QtWidgets.QWidget(MainWindow)
self.centralwidget.setObjectName("centralwidget")
self.html_code = QtWebEngineWidgets.QWebEngineView(self.centralwidget)
self.html_code.setGeometry(QtCore.QRect(0, 0, 901, 621))
self.html_code.setUrl(QtCore.QUrl("about:blank"))
self.html_code.setObjectName("html_code")
MainWindow.setCentralWidget(self.centralwidget)
self.retranslateUi(MainWindow)
QtCore.QMetaObject.connectSlotsByName(MainWindow)
def retranslateUi(self, MainWindow):
pass
from PyQt5 import QtWebEngineWidgets
我知道最简单的方法是使用 QWebChannel。我找到了一个示例 here,但我无法根据我的情况对其进行调整。
有什么建议吗?
为了使工作更有条理,我将 javascript 代码分离到一个名为 useless.js.
的新文件中你应该做的是创建一个QWebChannel对象,在页面上设置它并注册这个对象,你还必须创建一个接收信息的slot:
class ShowMap_fun(QMainWindow):
def __init__(self):
super().__init__()
self.map_ui = Ui_tmy3page() # The name of my top level object is MainWindow
self.map_ui.setupUi(self)
channel = QtWebChannel.QWebChannel(self.map_ui.html_code.page())
self.map_ui.html_code.page().setWebChannel(channel)
channel.registerObject("jshelper", self)
self.map_ui.html_code.load(QtCore.QUrl.fromLocalFile(QtCore.QDir.current().filePath("useless.html")))
@QtCore.pyqtSlot(float, float)
def markerMoved(self, lat, lng):
print(lat, lng)
然后您必须将 qwebchannel.js
文件添加到 .html
useless.html
<html>
<head>
<meta name="viewport" content="initial-scale=1.0, user-scalable=yes"/>
<script type="text/javascript" src="./qwebchannel.js"></script>
<script type="text/javascript" src="http://maps.google.com/maps/api/js?sensor=false"></script>
<script type="text/javascript" src="useless.js"></script>
</head>
[...]
代码js中必须获取对象:
useless.js
var jshelper;
new QWebChannel(qt.webChannelTransport, function (channel) {
jshelper = channel.objects.jshelper;
});
[...]
google.maps.event.addListener(marker, 'drag', function () {
updateMarkerStatus('Dragging...');
updateMarkerPosition(marker.getPosition());
jshelper.markerMoved(marker.position.lat(), marker.position.lng());
});
完整的例子可以在下面找到link