openlayers矢量功能z-indexing

Question

我很难尝试理解矢量特征的z索引.

当我在网上搜索信息时,我发现了这些链接:http : //openlayers.org/dev/examples/ordering.html http://osgeo-org.1803224.n2.nabble.com/Bug-in-using- graphicZIndex-td2648665.html 和 http://osgeo-org.1803224.n2.nabble.com/graphicZIndex-of-vector-features-td3919627.html

我做的是设置样式,就像它们显示在第一个链接上:

 this.vectorsLayer = new OpenLayers.Layer.Vector("Vectors", {
                styleMap: new OpenLayers.StyleMap({
                    "default": {
                    'strokeColor': "#ff9933",
                    'strokeWidth': 5
                    },
                    "select": {
                        'strokeColor': "#3399ff"
                    }
                })
            }
        );
    this.carsLayer = new OpenLayers.Layer.Vector("Cars", {'rendererOptions': {yOrdering: false, zIndexing: true}});

     this.startIconStyle = {'externalGraphic':this.startIconUrl};

     this.parkIconStyle = {'externalGraphic':this.parkIconUrl};

     this.endIconStyle = {'externalGraphic':this.endIconUrl};

     this.defaultStyles = {
             //'label':getLabel(),
             'graphicZIndex':745,
            'graphicXOffset':-13,
            'graphicYOffset':-41,
            'graphicWidth':26,
            'graphicHeight':41,
            'strokeLinecap':'round',
            'strokeColor':"#000000",
            'strokeWidth':2,
            'strokeOpacity':1,
            'fillOpacity':1}
        //style of path that car has used 
    this.drivedStyle = {
            'strokeWidth': 3,
            'strokeOpacity': 1,
            'strokeColor': "#3399ff",
            'strokeDashstyle': "dash"
        }

当我创建标记时,我会这样做:

var routePoint = this.points[this.routePos].clone();
var newstyleSite = OpenLayers.Util.extend(this.startIconStyle, this.defaultStyles ,OpenLayers.Feature.Vector.style['default']);
this.routePointFeature = new OpenLayers.Feature.Vector(routePoint, {}, newstyleSite);
this.vectorsLayer.addFeatures(this.routePointFeature);

当我查看该标记的z-index时,z-index设置为auto而不是745,它位于this.defaultStyles中.

这给我们带来了第三个链接...我完全听不懂,导致其他任何地方的设置风格完全一样,就像我现在所说的那样.

也没有

this.routePointFeature.attributes.zIndex = 745; 

改变一切.即使它显然适用于第一个链接/示例.

这个z索引应该如何工作？为什么它在我的情况下不起作用？我究竟做错了什么？或者有什么问题吗？

编辑:很多人都看过这个问题,并对答案进行了评价.然而,我不得不处理其他事情,并且暂时没有与opelayers合作.有些人看过这个答案可以证实答案是有效的,所以我可以接受吗？

艾伦

Answer 1

您必须为矢量图层启用z-indexing.

this.vectorsLayer = new OpenLayers.Layer.Vector("Vectors", {
  styleMap: <your style map>,
  rendererOptions: { zIndexing: true }
});

此外,OpenLayers.Util.extend只接受两个参数,第一个参数是目标(即第二个参数,源,将合并到其中).如果要组合多个对象,可以使用jQuery.extend或多次调用OpenLayers.Util.extend:

OpenLayers.Util.extend(this.startIconStyle, OpenLayers.Feature.Vector.style['default'] );
OpenLayers.Util.extend( this.startIconStyle, this.defaultStyles );

要么

jQuery.extend( this.startIconStyle, OpenLayers.Feature.Vector.style['default'], this.defaultStyles );

这两个都将导致this.startIconStyle包含this.startIconStyle,OpenLayers.Feature.Vector.style ['default']和this.defaultStyles的并集.

你真正想要的是:

var newstyleSite = {};
jQuery.extend( newstyleSite,  OpenLayers.Feature.Vector.style['default'], this.defaultStyles, this.startIconStyle );