如何使用 QWebEngineView 打开下载文件对话框?

2022-01-12 00:00:00 python pyqt pyqt5 qwebengineview

问题描述

我正在构建一个 pyqt5 桌面界面,我在其中使用 QWebEngineView 来显示一个 html 文件,我在其中显示一个传单地图.这工作正常.下一步是导出用户添加到地图的所有要素.当我点击地图上的导出功能"时,什么也没有发生,但是当我在 Chromium 网络浏览器上打开相同的 html 文件时,导出功能"会打开下载对话框.

I'm building a pyqt5 desktop interface where I'm using QWebEngineView to show a html file where I show a Leaflet map. This is working fine. The next step is to export all features the user added to the map. When I click on "Export Features" on the map nothing happen, but when I open the same html file on my Chromium web browser, the "Export feature" opens the download dialog fine.

PyQt5 脚本:

self.MainWindow.webMapViewer = QtWebEngineWidgets.QWebEngineView()
self.MainWindow.webPageLayout.addWidget(self.MainWindow.webMapViewer)
self.html_path = os.path.split(os.path.abspath(__file__))[0] + r'/html/test.html'
self.MainWindow.webMapViewer.load(QtCore.QUrl().fromLocalFile(self.html_path))

HTML:

<!DOCTYPE html>
        <html lang="en">
          <head>
            <meta charset="utf-8">
            <meta name='viewport' content='width=device-width, initial-scale=1.0, maximum-scale=1.0, user-scalable=no' />
            <title>FazMaraneyRGB_transparent_mosaic_group1</title>

            <!-- Leaflet -->
            <link rel="stylesheet" href="http://cdn.leafletjs.com/leaflet-0.7.5/leaflet.css" />
            <script src="http://cdn.leafletjs.com/leaflet-0.7.5/leaflet.js"></script>

            <!-- Leaflet.draw -->
            <link rel="stylesheet" href="https://unpkg.com/leaflet-draw@0.4.1/dist/leaflet.draw.css" />
            <script src="https://unpkg.com/leaflet-draw@0.4.1/dist/leaflet.draw.js"></script>

            <!-- Leaflet Ajax -->
            <script src="https://cdnjs.cloudflare.com/ajax/libs/leaflet-ajax/2.1.0/leaflet.ajax.min.js"></script>

            <!-- Leaflet Measument -->
            <link rel="stylesheet" href="http://ljagis.github.io/leaflet-measure/leaflet-measure.css" />
            <script src="http://ljagis.github.io/leaflet-measure/leaflet-measure.min.js"></script>


            <style>
                body { margin:0; padding:0; }
                body, table, tr, td, th, div, h1, h2, input { font-family: "Calibri", "Trebuchet MS", "Ubuntu", Serif; font-size: 11pt; }
                #map { position:absolute; top:0; bottom:0; width:100%; } /* full size */
                .ctl {
                    padding: 2px 10px 2px 10px;
                    background: white;
                    background: rgba(255,255,255,0.9);
                    box-shadow: 0 0 15px rgba(0,0,0,0.2);
                    border-radius: 5px;
                    text-align: right;
                }
                .title {
                    font-size: 18pt;
                    font-weight: bold;
                }
                .src {
                    font-size: 10pt;
                }
                #delete, #export {
                    position: absolute;
                    top:100px;
                    right:10px;
                    z-index:100;
                    background:white;
                    color:black;
                    padding:6px;
                    border-radius:4px;
                    font-family: 'Helvetica Neue';
                    cursor: pointer;
                    font-size:12px;
                    text-decoration:none;
                }
                #export {
                    top:130px;
                }
            </style>

        </head>
        <body>

        <div id='map'></div>
        <div id='delete'>Delete Features</div>
        <a href='#' id='export'>Export Features</a>

        <script>
        /* **** Leaflet **** */

        // Base layers
        //  .. OpenStreetMap
        var osm = L.tileLayer('http://{s}.tile.osm.org/{z}/{x}/{y}.png', {attribution: '&copy; <a href="http://osm.org/copyright">OpenStreetMap</a> contributors'});

        //  .. White background
        var white = L.tileLayer("data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAAQAAAAEAAQMAAABmvDolAAAAA1BMVEX///+nxBvIAAAAH0lEQVQYGe3BAQ0AAADCIPunfg43YAAAAAAAAAAA5wIhAAAB9aK9BAAAAABJRU5ErkJggg==");

        // Overlay layers (TMS)
        var lyr1 = L.tileLayer('./tiles/{z}/{x}/{y}.png', {tms: true, maxZoom: 22, opacity: 0.9, attribution: ""});

        // Map
        var map = L.map('map', {
            measureControl: true,
            center: [-18.3604868606589, -52.694255477616245],
            zoom: 22,
            minZoom: 0,
            maxZoom: 22,
            layers: [osm]
        });

        lyr1.addTo(map);

        //Geojson Layers


        var basemaps = {"OpenStreetMap": osm, "Without background": white}
        var overlaymaps = {"Layer 1": lyr1}

        // Title
        var title = L.control();
        title.onAdd = function(map) {
            this._div = L.DomUtil.create('div', 'ctl title');
            this.update();
            return this._div;
        };
        title.update = function(props) {
            this._div.innerHTML = "FazMaraneyRGB_transparent_mosaic_group1";
        };
        title.addTo(map);

        // Note
        var src = 'Generated by Hawkit';
        var title = L.control({position: 'bottomleft'});
        title.onAdd = function(map) {
            this._div = L.DomUtil.create('div', 'ctl src');
            this.update();
            return this._div;
        };
        title.update = function(props) {
            this._div.innerHTML = src;
        };
        title.addTo(map);

        var featureGroup = L.featureGroup().addTo(map);

        var drawControl = new L.Control.Draw({
            edit: {
                featureGroup: featureGroup
            }
        }).addTo(map);

        map.on('draw:created', function(e) {

            // Each time a feaute is created, it's added to the over arching feature group
            featureGroup.addLayer(e.layer);
        });

        // on click, clear all layers
        document.getElementById('delete').onclick = function(e) {
            featureGroup.clearLayers();
        }

        document.getElementById('export').onclick = function(e) {
            // Extract GeoJson from featureGroup
            var data = featureGroup.toGeoJSON();

            // Stringify the GeoJson
            var convertedData = 'text/json;charset=utf-8,' + encodeURIComponent(JSON.stringify(data));

            // Create export
            document.getElementById('export').setAttribute('href', 'data:' + convertedData);
            document.getElementById('export').setAttribute('download','data.geojson');
        }


        // Add base layers
        L.control.layers(basemaps, overlaymaps, {collapsed: true}).addTo(map);

        // Fit to overlay bounds (SW and NE points with (lat, lon))
        map.fitBounds([[-18.36827062251916, -52.6871074784942], [-18.35270287637126, -52.7014028427423]]);

        </script>

        </body>
        </html>


解决方案

那个弹窗是由浏览器生成的,对于QWebEngine我们必须创建它.首先,必须检测指示下载的信号,该信号是来自QWebEngineProfiledownloadRequested.该信号向我们发送一个处理下载的 QWebEngineDownloadItem 对象,在其中我们借助 QFileDialog 创建一个对话窗口.对于这种情况,我们将创建一个自定义的 QWebEnginePage,如下所示:

That popup window is generated by the browser, in the case of QWebEngine we must create it. To start, the signal indicating the download must be detected, and this signal is downloadRequested from the QWebEngineProfile. That signal sends us a QWebEngineDownloadItem object that handles the download, in it we create a dialog window with the help of QFileDialog. For this case we will create a custom QWebEnginePage as shown below:

index.html

<!DOCTYPE html>
<html lang="en">

<head>
    <meta charset="utf-8">
    <meta name='viewport' content='width=device-width, initial-scale=1.0, maximum-scale=1.0, user-scalable=no' />
    <title>FazMaraneyRGB_transparent_mosaic_group1</title>

    <!-- Leaflet -->
    <link rel="stylesheet" href="http://cdn.leafletjs.com/leaflet-0.7.5/leaflet.css" />
    <script src="http://cdn.leafletjs.com/leaflet-0.7.5/leaflet.js"></script>

    <!-- Leaflet.draw -->
    <link rel="stylesheet" href="https://unpkg.com/leaflet-draw@0.4.1/dist/leaflet.draw.css" />
    <script src="https://unpkg.com/leaflet-draw@0.4.1/dist/leaflet.draw.js"></script>

    <!-- Leaflet Ajax -->
    <script src="https://cdnjs.cloudflare.com/ajax/libs/leaflet-ajax/2.1.0/leaflet.ajax.min.js"></script>

    <!-- Leaflet Measument -->
    <link rel="stylesheet" href="http://ljagis.github.io/leaflet-measure/leaflet-measure.css" />
    <script src="http://ljagis.github.io/leaflet-measure/leaflet-measure.min.js"></script>

    <style>
        body {
            margin: 0;
            padding: 0;
        }
        
        body,
        table,
        tr,
        td,
        th,
        div,
        h1,
        h2,
        input {
            font-family: "Calibri", "Trebuchet MS", "Ubuntu", Serif;
            font-size: 11pt;
        }
        
        #map {
            position: absolute;
            top: 0;
            bottom: 0;
            width: 100%;
        }
        /* full size */
        
        .ctl {
            padding: 2px 10px 2px 10px;
            background: white;
            background: rgba(255, 255, 255, 0.9);
            box-shadow: 0 0 15px rgba(0, 0, 0, 0.2);
            border-radius: 5px;
            text-align: right;
        }
        
        .title {
            font-size: 18pt;
            font-weight: bold;
        }
        
        .src {
            font-size: 10pt;
        }
        
        #delete,
        #export {
            position: absolute;
            top: 100px;
            right: 10px;
            z-index: 100;
            background: white;
            color: black;
            padding: 6px;
            border-radius: 4px;
            font-family: 'Helvetica Neue';
            cursor: pointer;
            font-size: 12px;
            text-decoration: none;
        }
        
        #export {
            top: 130px;
        }
    </style>

</head>

<body>

    <div id='map'></div>
    <div id='delete'>Delete Features</div>
    <a href='#' id='export'>Export Features</a>

    <script>
        /* **** Leaflet **** */

        // Base layers
        //  .. OpenStreetMap
        var osm = L.tileLayer('http://{s}.tile.osm.org/{z}/{x}/{y}.png', {
            attribution: '&copy; <a href="http://osm.org/copyright">OpenStreetMap</a> contributors'
        });

        //  .. White background
        var white = L.tileLayer("data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAAQAAAAEAAQMAAABmvDolAAAAA1BMVEX///+nxBvIAAAAH0lEQVQYGe3BAQ0AAADCIPunfg43YAAAAAAAAAAA5wIhAAAB9aK9BAAAAABJRU5ErkJggg==");

        // Overlay layers (TMS)
        var lyr1 = L.tileLayer('./tiles/{z}/{x}/{y}.png', {
            tms: true,
            maxZoom: 22,
            opacity: 0.9,
            attribution: ""
        });

        // Map
        var map = L.map('map', {
            measureControl: true,
            center: [-18.3604868606589, -52.694255477616245],
            zoom: 22,
            minZoom: 0,
            maxZoom: 22,
            layers: [osm]
        });

        lyr1.addTo(map);

        //Geojson Layers

        var basemaps = {
            "OpenStreetMap": osm,
            "Without background": white
        }
        var overlaymaps = {
            "Layer 1": lyr1
        }

        // Title
        var title = L.control();
        title.onAdd = function(map) {
            this._div = L.DomUtil.create('div', 'ctl title');
            this.update();
            return this._div;
        };
        title.update = function(props) {
            this._div.innerHTML = "FazMaraneyRGB_transparent_mosaic_group1";
        };
        title.addTo(map);

        // Note
        var src = 'Generated by Hawkit';
        var title = L.control({
            position: 'bottomleft'
        });
        title.onAdd = function(map) {
            this._div = L.DomUtil.create('div', 'ctl src');
            this.update();
            return this._div;
        };
        title.update = function(props) {
            this._div.innerHTML = src;
        };
        title.addTo(map);

        var featureGroup = L.featureGroup().addTo(map);

        var drawControl = new L.Control.Draw({
            edit: {
                featureGroup: featureGroup
            }
        }).addTo(map);

        map.on('draw:created', function(e) {

            // Each time a feaute is created, it's added to the over arching feature group
            featureGroup.addLayer(e.layer);
        });

        // on click, clear all layers
        document.getElementById('delete').onclick = function(e) {
            featureGroup.clearLayers();
        }

        document.getElementById('export').onclick = function(e) {
            // Extract GeoJson from featureGroup
            var data = featureGroup.toGeoJSON();

            // Stringify the GeoJson
            var convertedData = 'text/json;charset=utf-8,' + encodeURIComponent(JSON.stringify(data));

            // Create export
            document.getElementById('export').setAttribute('href', 'data:' + convertedData);
            document.getElementById('export').setAttribute('download', 'data.geojson');
        }

        // Add base layers
        L.control.layers(basemaps, overlaymaps, {
            collapsed: true
        }).addTo(map);

        // Fit to overlay bounds (SW and NE points with (lat, lon))
        map.fitBounds([
            [-18.36827062251916, -52.6871074784942],
            [-18.35270287637126, -52.7014028427423]
        ]);
    </script>

</body>

</html>

ma​​in.py

from PyQt5 import QtWebEngineWidgets, QtWidgets, QtCore

class WebEnginePage(QtWebEngineWidgets.QWebEnginePage):
    def __init__(self, *args, **kwargs):
        QtWebEngineWidgets.QWebEnginePage.__init__(self, *args, **kwargs)
        self.profile().downloadRequested.connect(self.on_downloadRequested)

    @QtCore.pyqtSlot(QtWebEngineWidgets.QWebEngineDownloadItem)
    def on_downloadRequested(self, download):
        old_path = download.path()
        suffix = QtCore.QFileInfo(old_path).suffix()
        path, _ = QtWidgets.QFileDialog.getSaveFileName(self.view(), "Save File", old_path, "*."+suffix)
        if path:
            download.setPath(path)
            download.accept()


if __name__ == '__main__':
    import sys

    sys.argv.append("--remote-debugging-port=8000")
    sys.argv.append("--disable-web-security")

    app = QtWidgets.QApplication(sys.argv)
    view = QtWebEngineWidgets.QWebEngineView()
    page = WebEnginePage(view)
    view.setPage(page)
    path = QtCore.QDir.current().filePath("index.html")
    view.load(QtCore.QUrl.fromLocalFile(path))
    view.show()
    sys.exit(app.exec_())

<小时>

在你的情况下:


In your case:

self.MainWindow.webMapViewer = QtWebEngineWidgets.QWebEngineView()
self.MainWindow.webPageLayout.addWidget(self.MainWindow.webMapViewer)
page = WebEnginePage(self.MainWindow.webMapViewer) # create page
self.MainWindow.webMapViewer.setPage(page) # set page
self.html_path = os.path.split(os.path.abspath(__file__))[0] + r'/html/test.html'
self.MainWindow.webMapViewer.load(QtCore.QUrl().fromLocalFile(self.html_path))

<小时>

加号:

如果要设置已定义的路线,请使用以下命令:

If you want to set a defined route use the following:

@QtCore.pyqtSlot(QtWebEngineWidgets.QWebEngineDownloadItem)
def on_downloadRequested(self, download):
    directory = "/path/of/directory"
    filename = QtCore.QFileInfo(download.path()).fileName()
    download.setPath(QtCore.QDir(directory).filePath(filename))
    download.accept()

相关文章