Google 地图屏幕截图不适用于使用 html2canvas 的标记和标记集群

Question

我正在使用 Flask 做 python 项目，其中我使用 google 地图 api 来显示项目中的地图。我实现了 html2canvas 脚本来成功捕获地图。但我在地图上也有标记，但它没有捕获。所以我尝试使用 html2canvasPythonProxy 这是我的模板 gpsDataMap 的 javascript 文件片段：

$(window).load(function(){
      $('#saveMap').click(function(){
          html2canvas(document.getElementById('map'), {
             "logging": true, //Enable log (use Web Console for get Errors and Warnings)
             "proxy":"/surveyApp/gpsDataMap/html2canvas-proxy",
             useCORS:true,
             "onrendered": function(canvas) {
              var img = new Image();
             img.onload = function() {
             img.onload = null;
             document.body.appendChild(img);
           };
            img.onerror = function() {
            img.onerror = null;
            if(window.console.log) {
               window.console.log("Not loaded image from canvas.toDataURL");
                  } else {
            alert("Not loaded image from canvas.toDataURL");
               }
              };
                img.src = canvas.toDataURL("image/png");
               }
            });

        });
    });

还有我的Python代码片段：

import os
import datetime

from flask import Flask, request, render_template, redirect, url_for, flash, Response
from flask.json import dumps
from flask import json
from flask import g, Blueprint, session, abort
from flask_principal import Identity, identity_changed, identity_loaded, RoleNeed, AnonymousIdentity
from flask_login import LoginManager, login_user, login_required, logout_user
from app import app
from model.user_info import SurveyForms

from flask.ext.pymongo import PyMongo

from inspect import getmembers, isfunction
import formConfig
import formTree
import fieldChoices
from dashboard import dashboardData
from collections import namedtuple
from pymongo import MongoClient
from flask import request


from html2canvasproxy import * #include html2canvasproxy in your application
import urlparse
import re




surveyApp_module = Blueprint('surveyApp_module', __name__)


app.config['MONGO_HOST'] = 'localhost'
app.config['MONGO_PORT'] = 27017
app.config['MONGO_DBNAME'] = 'survey'
mongo = PyMongo(app)

h2c = None
real_path = os.getcwd() + '/static/images'
virtual_path = '/gpsDataMap/images/'

@surveyApp_module.route('/')
@login_required
def show_formList():
    forms = []
    forms = [form.form_name for form in SurveyForms.select().where(SurveyForms.organization_name==session['organization_id'])]
    # strip .xml from string to compare with returnData
    forms =  [form.replace('.xml','') for form in forms]
    returnData = mongo.db.collection_names()
    returnData.pop(returnData.index('system.indexes'))
    intersected_forms = list(set(forms).intersection(returnData))
    if len(intersected_forms):
        return render_template('index_pjj.html', surveyEntries=intersected_forms)
    return render_template('index_pjj.html', surveyEntries=['No Survey'])

@surveyApp_module.route('/dashboard', methods=['POST'])
def dashboard():
    formName = request.form['whichSurvey']
    session['formName'] = formName
    formtree = formTree.formParseDict(formName)
    returnData = dashboardData(formName, mongo.db)
    summaryData = totalSummary(formName, mongo.db)
    jsonData = json.dumps(returnData)
    return render_template('dashboard.html', formName=formName, formTree=formtree, returnData=returnData, summaryData=summaryData, jsonData=jsonData)


@surveyApp_module.route('/gpsDataView', methods=['POST'])
def gpsDataView():
    formName = request.form['whichSurvey']
    gpsFields = formConfig.survey[formName]['gpsField']
    (location, fieldName, fieldSelection, fieldChoicesList) = "", "", "", []
    location = request.form['location']
    fieldName = request.form['fieldName']
    try:
        fieldSelection = request.form['fieldChoices']
    except KeyError:
        pass
    fieldChoicesList = request.form.getlist('fieldChoicesList')
    fieldData = commonFunctions.vizFieldList(formName)
    totalFieldData = commonFunctions.vizFieldListFull(formName)
    locationIdentifiers = fieldChoices.locationFieldChoices(formName, mongo.db)
    returnData = gpsVariate.getDataforGPSMap(formName, mongo.db, gpsFields, location, fieldName, fieldSelection, fieldChoicesList)
    return render_template('gpsDataMap.html', returnData=returnData, formName=formName, fieldData=fieldData, totalFieldData=totalFieldData, locationIdentifiers=locationIdentifiers)



    #Copy html2canvas.js to static folder (If not use cdns)
@surveyApp_module.route('/gpsDataMap/html2canvas.js')
def html2canvas_js():
    return app.send_static_file('html2canvas.js')



@surveyApp_module.route('/gpsDataMap/html2canvas-proxy')
def html2canvas_proxy():
    print ("is this proxy really calling ");
    h2c = html2canvasproxy(request.args.get('callback'), request.args.get('url'))
    h2c.userAgent(request.headers['user_agent'])
    # import pdb;pdb.set_trace()


    if request.referrer is not None:
        h2c.referer(request.referrer)

    h2c.route(real_path, virtual_path)

    r = h2c.result()
    # print r['mime']
    # print r['data']

    return Response(r['data'], mimetype=r['mime'])




 # Get images saved by html2canvasproxy
@surveyApp_module.route('/gpsDataMap/html2canvas/images/<image>')
def images(image):
    res = html2canvasproxy.resource(real_path, image)

    if res is None:
        return '', 404

    else:
        return res['data']

这是我的 main.py 脚本：

from app import app, db


from auth import *
from admin import admin
from model import *
from view import *
from filters.user_privilege import check_privilege
from filters.form_filter import filter_type

# custom filters
app.jinja_env.filters['check_privilege'] = check_privilege
app.jinja_env.filters['filter_type'] = filter_type


from surveyApp import surveyApp_module
app.register_blueprint(surveyApp_module, url_prefix='/surveyApp')

from view.accounts.login import login_module
app.register_blueprint(login_module)


if __name__ == '__main__':
    app.run(port=5555)

这样做时，我在控制台中看到以下内容：

html2canvas: Preload starts: finding background-images html2canvas.js:21
html2canvas: Preload: Finding images html2canvas.js:21
html2canvas: Preload: Done. html2canvas.js:21
html2canvas: start: images: 1 / 23 (failed: 0) html2canvas.js:21
html2canvas: start: images: 2 / 23 (failed: 0) html2canvas.js:21
html2canvas: start: images: 3 / 23 (failed: 0) html2canvas.js:21
html2canvas: start: images: 4 / 23 (failed: 0) html2canvas.js:21
html2canvas: start: images: 5 / 23 (failed: 0) html2canvas.js:21
html2canvas: start: images: 6 / 23 (failed: 0) html2canvas.js:21
html2canvas: start: images: 7 / 23 (failed: 0) html2canvas.js:21
html2canvas: start: images: 8 / 23 (failed: 0) html2canvas.js:21
html2canvas: start: images: 9 / 23 (failed: 0) html2canvas.js:21
html2canvas: start: images: 10 / 23 (failed: 0) html2canvas.js:21
html2canvas: start: images: 11 / 23 (failed: 0) html2canvas.js:21
html2canvas: start: images: 12 / 23 (failed: 0) html2canvas.js:21
html2canvas: start: images: 13 / 23 (failed: 0) html2canvas.js:21
html2canvas: start: images: 14 / 23 (failed: 0) html2canvas.js:21
html2canvas: start: images: 15 / 23 (failed: 0) html2canvas.js:21
html2canvas: start: images: 16 / 23 (failed: 0) html2canvas.js:21
html2canvas: start: images: 17 / 23 (failed: 0) html2canvas.js:21
html2canvas: start: images: 18 / 23 (failed: 0) html2canvas.js:21
html2canvas: start: images: 19 / 23 (failed: 0) html2canvas.js:21
html2canvas: start: images: 20 / 23 (failed: 0) html2canvas.js:21
html2canvas: start: images: 21 / 23 (failed: 0) html2canvas.js:21
html2canvas: start: images: 22 / 23 (failed: 0) html2canvas.js:21
GET http://127.0.0.1:5555/home/bhim/app/surveyApp_bhim/images/a0af53c02bd2f2aed37f1d895edcf3485117c512.png 404 (NOT FOUND) html2canvas.js:2249
html2canvas: start: images: 23 / 23 (failed: 1) html2canvas.js:21
Finished loading images: # 23 (failed: 1) html2canvas.js:21
html2canvas: Error loading background: html2canvas.js:21
html2canvas: Renderer: Canvas renderer done - returning canvas obj 

更新： 调试器结果：

folder => images,
timeout => 30,
mimetype => application/javascript,
ua => Mozilla/5.0 (X11; Ubuntu; Linux x86_64; rv:29.0) Gecko/20100101 Firefox/29.0,
host => 127.0.0.1:5555,
scheme => http,
ref => ,
url => http://www.google.com,
callback => console.log,
default_callback => console.log,
status => 0,
routePath => /static/images/,
savePath => /home/bhim/app/surveyApp_bhim/static/images/,
prefix => htc_,
real_extension => ,
mimes => ['image/bmp', 'image/windows-bmp', 'image/ms-bmp', 'image/jpeg', 'image/jpg', 'image/png', 'image/gif', 'text/html', 'application/xhtml', 'application/xhtml+xml']

已更新谷歌地图图像的屏幕截图

标记未被捕获。

Answer 1

请先尝试一下，它可能对您有用。

<script src="http://maps.googleapis.com/maps/api/js?key=AIzaSyDY0kkJiTPVd2U7aTOAwhc9ySH6oHxOIYM&sensor=false">
<script src="http://ajax.googleapis.com/ajax/libs/jquery/1.8.2/jquery.js"></script> 
<script type="text/javascript" src ="http://code.jquery.com/jquery-1.9.0.min.js"></script>
<script type="text/javascript" src="html2canvas.js?rev032"></script> 



<script type="text/javascript">

function initialize()
    {
    var mapProp = {
          center:new google.maps.LatLng(51.508742,-0.120850),
          zoom:5,
          mapTypeId:google.maps.MapTypeId.ROADMAP
      };
    var map=new google.maps.Map(document.getElementById("googleMap"), mapProp);
}

google.maps.event.addDomListener(window, 'load', initialize);

 $(window).load(function(){

    $('#load').click(function(){

            html2canvas($('#googleMap'), {
            useCORS: true,
                onrendered: function (canvas) {
                var dataUrl= canvas.toDataURL("image/png").replace("image/png", "image/octet-stream");

                window.location.href = dataUrl;
                                    }
            });

    });
});
</script>
</head>

<body>
<div id="googleMap" style="width:500px;height:380px;"></div>
<input type="button" value="Save" id="load"/>
</body>

Answer 2

1) 使用

useCORS:true

或使用

proxy

，切勿同时使用两者。

2）你们的路线不同，请参阅：

• virtual_path = '/gpsDataMap/images/'

• @surveyApp_module.route('/gpsDataMap/html2canvas/images/<image>')

3）你的代理路由似乎是错误的（在你的Javascript中）：

• "proxy":"/surveyApp/gpsDataMap/html2canvas-proxy",

• @surveyApp_module.route('/gpsDataMap/html2canvas-proxy')

---

您没有意识到所有错误，为什么

userCORS

与“PROXY”会混淆。

修复所有路由（路由是它们的虚拟路径）并修复你的javascript（不要使用

userCORS:

），请参阅：

$(window).load(function(){
    $('#saveMap').click(function(){
        html2canvas(document.getElementById('map'), {
                "logging": true, //Enable log (use Web Console for get Errors and Warnings)
                //useCORS:true, "COMMENTED", remove useCORS
                "proxy": YOUR_FIXED_ROUTE,
                "onrendered": function(canvas) {
                    var img = new Image();
                    img.onload = function() {
                        img.onload = null;
                        document.body.appendChild(img);
                    };

                    img.onerror = function() {
                        img.onerror = null;
                        if(window.console.log) {
                            window.console.log("Not loaded image from canvas.toDataURL");
                        } else {
                            alert("Not loaded image from canvas.toDataURL");
                        }
                    };
                    img.src = canvas.toDataURL("image/png");
                }
        });
    });
});

---

看，这是与“路线”混合的绝对路径：

GET http://127.0.0.1:5555/home/bhim/app/surveyApp_bhim/images/a0af53c02bd2f2aed37f1d895edcf3485117c512.png 404 (NOT FOUND) html2canvas.js:2249

代理响应的路由因任何原因错误，使用这个：

1）编辑你的代码，如下所示：

@surveyApp_module.route('/gpsDataMap/html2canvas-proxy')
def html2canvas_proxy():
    print ("is this proxy really calling ");
    h2c = html2canvasproxy(request.args.get('callback'), request.args.get('url'))
    h2c.userAgent(request.headers['user_agent'])

    if request.referrer is not None:
        h2c.referer(request.referrer)

    if request.args.get('debug_vars'): #Added
        return Response((',\n'.join(h2c.debug_vars())), mimetype='text/plain') #Added

    h2c.route(real_path, virtual_path)

    r = h2c.result()
    return Response(r['data'], mimetype=r['mime'])

2）在浏览器中运行：

http://127.0.0.1:5000/gpsDataMap/html2canvas-proxy?callback=console.log&url=http://www.google.com&debug_vars=1

3）获取结果并发布到您的问题中。

Answer 3

保存标记（html2canvas 的解决方法）：

（来源#1）：http://humaan.com/custom-html-markers-google-maps/
（来源#2）：http://jsfiddle.net/BCr2B/99/

实现您自己的标记既快速又简单，从而避免了受污染的问题。

function HTMLMarker(lat, lng, col) {
    this.lat = lat;
    this.lng = lng;
    this.col = col;
    this.pos = new google.maps.LatLng(lat, lng);
}

HTMLMarker.prototype = new google.maps.OverlayView();
HTMLMarker.prototype.onRemove = function() {}
HTMLMarker.prototype.onAdd = function() {}
HTMLMarker.prototype.draw = function() {
    var self = this;
    var div = this.div;

    if(!div) {
        div = this.div = document.createElement('div');
        div.className = 'marker';
        div.style.position = 'absolute';
        div.style.width = '32px';
        div.style.height = '32px';

        switch(this.col) {
            case "green":
                div.innerHTML = '<img src="/images/green-dot.png">';
                break;
            case "yellow":
                div.innerHTML = '<img src="/images/yellow-dot.png">';
                break;
            case "red":
                div.innerHTML = '<img src="/images/red-dot.png">';
                break;
        }

        var panes = this.getPanes();
        panes.overlayImage.appendChild(div);
    }


    var position = this.getProjection().fromLatLngToDivPixel(this.pos);
    div.style.left = position.x - 16 + "px";
    div.style.top = position.y - 32 + "px";
}

然后只需添加：

var htmlMarker = new HTMLMarker(data[gps].Latitude, data[gps].Longitude, "green");
markersArray.push(htmlMarker.setMap(map));

以这种方式导出时，地图标记会成功添加，因为它们来自本地源。

Answer 4

您是否尝试过在标记选项中设置optimized: false？

它将使谷歌地图将每个标记渲染为 DOM 元素，从而使 html2canvas 能够找到它们并渲染它们。

为我工作。