javascript - 将参数传递给 oneeachfeature 传单

Question

我试图通过点击一个多边形来传递一个参数来绑定(bind)它，我有以下内容:

var mapLayer = new L.TopoJSON(jsonMap, {style: style, onEachFeature: onEachFeature.bind(null,null,selectionManager), pane:'borders'}).addTo(this.map); 


 function onEachFeature(feature, layer, selectionManager) {
                    console.log(selectionManager)
                    layer.on({
                        mouseover: highlightFeature,
                        mouseout: resetHighlight,
                        click: dataFilter.bind(null,ID)
                    });
                }

 function dataFilter(selectionManager,e){
                    var layer = e.target;
                    var zoneName = layer.feature.properties.Index;
                    console.log(zoneName)
                    console.log(selectionManager);
                }

所以我的目标是读取 dataFilter 中的一个参数(在本例中是 selectionManager)

Answer 1

根据 Leaflet 文档，onEachFeature 需要是一个接收两个参数(feature 和 layer)的函数。使用 Function.prototype.bind在您使用它的方式中，它并没有按照您的意愿行事。

相反，创建一个 closure :

function onEachFeatureClosure(dataFilter) {
    return function onEachFeature(feature, layer) {
        // Your own logic, that uses dataFilter as well as feature and layer
    }
}

L.topoJSON(jsonMap, {
     style: style, 
     onEachFeature: onEachFeatureClosure(selectionManager),
     pane:'borders'
}).addTo(this.map);

请注意，onEachFeatureClosure(selectionManager) 的返回值是一个类似于 function onEachFeature(feat, layer) {...} 的函数。