加载 JSON 文件并将其附加到地图

Question

我想加载 json 文件并将其附加到 Leaflet-Map。

<input type='file' accept='Json' onchange='loadFile(event)'>

上传 JSON 文件后，我很难处理它的内容。 JSON 文件的示例是：

{
    "type": "FeatureCollection",
    "features": 
    [
        {
        "type": "Feature",
        "properties": {
            "name": "Lagoa Stadium",
            "coordinate":"-22.975801, -43.217316",
            "venue_type": "Outdoor area",
            "event": [{"name":"Canoe Sprint","date_start":"2016-08-15", "date_end":"2016-08-20"},
                    {"name":"Rowing","date_start":"2016-08-6", "date_end":"2016-08-13"}],
            "link": "https://www.rio2016.com/en/venues/lagoa-stadium",
            "images":["http://secure.rio2016.com/sites/default/files/imagecache/360x270_maps_cities/lagoa_aereas_secao01_alexferro_05032015-9156_1.jpg", "https://upload.wikimedia.org/wikipedia/commons/6/6a/1_lagoa_rodrigo_de_freitas_rio_de_janeiro_2010.jpg","http://www.rio-de-janeiro-travel-information.com/images/marina-da-gloria-rio-de-janeiro-2016-olympics.jpg"],
            "capacity": "14,000",
            "parking": "-22.983465, -43.198912"
        },
        "geometry": 
        {
            "type": "Polygon",
            "coordinates": [
            [
                [
                  -43.21497917175292,
                  -22.979493188378516
                ],
                [
                  -43.21643829345703,
                  -22.9790190701661
                ],
                [
                  -43.21772575378418,
                  -22.97870299043356
                ],
                [
                  -43.217811584472656,
                  -22.977596705547032
                ],
                [
                  -43.21695327758788,
                  -22.976411390260754
                ],
                [
                  -43.2161808013916,
                  -22.975068020367633
                ],
                [
                  -43.21592330932617,
                  -22.971828073334315
                ],
                [
                  -43.216352462768555,
                  -22.970089533152084
                ],
                [
                  -43.21738243103027,
                  -22.968667074553263
                ],
                [
                  -43.21703910827637,
                  -22.967323627688746
                ],
                [
                  -43.21566581726074,
                  -22.96558502957624
                ],
                [
                  -43.21446418762207,
                  -22.96432058054304
                ],
                [
                  -43.212318420410156,
                  -22.96337223600826
                ],
                [
                  -43.21051597595215,
                  -22.962977090489098
                ],
                [
                  -43.20914268493652,
                  -22.96313514883533
                ],
                [
                  -43.2063102722168,
                  -22.962819031958123
                ],
                [
                  -43.20510864257812,
                  -22.96305611968531
                ],
                [
                  -43.204078674316406,
                  -22.964083495032888
                ],
                [
                  -43.20356369018555,
                  -22.966138222309887
                ],
                [
                  -43.20356369018555,
                  -22.96740265434445
                ],
                [
                  -43.20845603942871,
                  -22.971828073334315
                ],
                [
                  -43.207340240478516,
                  -22.974830953706174
                ],
                [
                  -43.204593658447266,
                  -22.973803660034452
                ],
                [
                  -43.201160430908196,
                  -22.974830953706174
                ],
                [
                  -43.20047378540039,
                  -22.97609530442847
                ],
                [
                  -43.20004463195801,
                  -22.97751768485142
                ],
                [
                  -43.20124626159668,
                  -22.978623970384902
                ],
                [
                  -43.202362060546875,
                  -22.979256129480273
                ],
                [
                  -43.207426071166985,
                  -22.980441419812312
                ],
                [
                  -43.214378356933594,
                  -22.980125343407142
                ],
                [
                  -43.21497917175292,
                  -22.979493188378516
                ]
              ]
            ]
        }
    }
    ]
}

如何读取此文件的内容并将其加载到我的地图中？
我设法加载了我服务器上的 JSON 文件：

$.getJSON('CompleteList.json', function (geojson) {
  jsonlayer = L.geoJson(geojson, {
    onEachFeature: function (feature, layer) {
      layer.bindPopup(feature.properties.name);
    }
  }).addTo(map);

现在我加载了文件并将其保存在变量中...但是现在呢？

var loadFile = function(event) {
    // Init
    var input = event.target;
    var reader = new FileReader();

    // Read the file
    reader.readAsText(input.files[0]);

    // Invoked when file is loading. 
    reader.onload = function(){

        // parse file to JSON object
        var jsonObject = reader.result;
        console.log(jsonObject);

    };
};

我希望我没有遗漏任何东西并且这不是一个愚蠢的问题:D

我的整个项目 post 代码太多了，但现在它看起来像这样：

Answer 1

您已成功读取用户文件的文本内容。

现在您需要将该文本转换为一个 JS 对象（实际上是 GeoJSON，但它实际上只是一个遵循特定约定的普通 JS 对象）。

为此，您只需使用 JSON.parse()。

然后你可以把它喂给Leaflet L.geoJson()工厂。

Answer 2

我想一旦你包含了 Leaflet-Map 库，JSON 对象将具有函数 addTo()，所以你需要先解析 json 对象。

var loadFile = function(event) {
// Init
var input = event.target;
var reader = new FileReader();

// Read the file
reader.readAsText(input.files[0]);

// Invoked when file is loading. 
reader.onload = function(){

    // parse file to JSON object
    var jsonObject = reader.result;
    var json = JSON.parse(jsonObject);
    jsonlayer = L.geoJson(json, {
onEachFeature: function (feature, layer) {
  layer.bindPopup(feature.properties.name);
}).addTo(map);
    console.log(jsonObject);

};
};

加载 JSON 文件并将其附加到地图

Load JSON file and append it to a map

javascript

json

file

leaflet

reader