Javascript 使用OpenLayers.Control.GetFeature初始化OpenLayers
我想知道是否有人能给我指出正确的方向,迫使OpenLayers.Control.GetFeature的BBOX始终处于long/lat坐标中。我正试图通过OpenLayers.Class来实现这一点,因此新控件将继承OpenLayers.control.GetFeature,只需在BBOX中做一些小修改。这就是我所做的:Javascript 使用OpenLayers.Control.GetFeature初始化OpenLayers,javascript,class,openlayers,Javascript,Class,Openlayers,我想知道是否有人能给我指出正确的方向,迫使OpenLayers.Control.GetFeature的BBOX始终处于long/lat坐标中。我正试图通过OpenLayers.Class来实现这一点,因此新控件将继承OpenLayers.control.GetFeature,只需在BBOX中做一些小修改。这就是我所做的: OpenLayers.Control.myGetFeature = OpenLayers.Class(OpenLayers.Control.GetFeature,{
OpenLayers.Control.myGetFeature = OpenLayers.Class(OpenLayers.Control.GetFeature,{
selectBox: function(position){
var opts = OpenLayers.Control.GetFeature(position);
var baseSRSutm = this.map.getprojectionObject();
var layerSRSdd = new OpenLayers.Projection('EPSG:4326');
opts.params.bbox = this.map.getExtent().transform(baseSRSutm,layerSRSdd).toBBOX(null,firstLayer.reverseAxisOrder());
}
return opts;
});
但我发现有些“}”不见了。这是使用OpenLayers.Class做我想做的事情的正确方法吗
非常感谢您的帮助
另外,我正在使用OpenLayers 2.11
编辑:
在函数内部移动“return opts;”解决了上述问题,但它抱怨类_名称丢失。此外,它仍然抱怨同样的问题,但在点击几下或几盒之后,它发送了请求,但是发送的bbox仍然在UTM中,问题出在哪里?这是代码:
var mycontrol = function(){
var protocol = new OpenLayers.Protocol.HTTP({
url: 'http://www.....',
format: new OpenLayers.Format.GeoJSON({
ignoreExtraDims: true,
'internalProjection': new OpenLayers.Projection('EPSG:900913'),
'externalProjection': new OpenLayers.Projection('EPSG:4326')
})
});
OpenLayers.Control.myGetFeature = OpenLayers.Class(OpenLayers.Control.GetFeature,{
selectBox: function(position){
var opts = OpenLayers.Control.GetFeature(position);
var baseSRSutm = this.map.getprojectionObject();
console.log('this is the baseSRSutm' + baseSRSutm); // doesnt appear in firebug
var layerSRSdd = new OpenLayers.Projection('EPSG:4326');
opts.params.bbox = this.map.getExtent().transform(baseSRSutm,layerSRSdd).toBBOX(null,firstLayer.reverseAxisOrder());
console.log('this is the opts.params.bbox' + opts.params.bbox); // doesnt appear in firebug
return opts;
},
CLASS_NAME: "OpenLayers.Control.myGetFeature"
});
return new OpenLayers.Control.myGetFeature({
protocol: protocol,
box: true,
click: true,
single: false,
clickTolerance: 10,
eventListeners:{
// some stuff
}
});
};
因为console.log没有出现在firebug中,所以我认为问题出在OpenLayers.Control.myGetFeature和OpenLayers.Class中。在我看来,“selectBox”函数是我所需要的函数,但是子类本身并没有被返回读取
请在此方面提供帮助,提前感谢,您的代码示例有一些语法错误。尝试将来使用一些javascript代码过滤器来帮助调试这些错误。这是您的代码,已修复:
OpenLayers.Control.myGetFeature = OpenLayers.Class(OpenLayers.Control.GetFeature,{
selectBox: function(position){
var opts = OpenLayers.Control.GetFeature(position);
var baseSRSutm = this.map.getprojectionObject();
var layerSRSdd = new OpenLayers.Projection('EPSG:4326');
opts.params.bbox = this.map.getExtent().transform(baseSRSutm,layerSRSdd).toBBOX(null,firstLayer.reverseAxisOrder());
return opts;
}
});
关于你关于定制GetFeature的问题,我认为你的思路是正确的。这和我的做法是一样的。OpenLayers建议在其应用程序中使用稍微不同的方法,但它执行相同的功能:
var control = new OpenLayers.Control.GetFeature();
OpenLayers.Util.extend(control, {
selectBox: function(position){
var opts = OpenLayers.Control.GetFeature(position);
var baseSRSutm = this.map.getprojectionObject();
var layerSRSdd = new OpenLayers.Projection('EPSG:4326');
opts.params.bbox = this.map.getExtent().transform(baseSRSutm,layerSRSdd).toBBOX(null,firstLayer.reverseAxisOrder());
return opts;
}
});
最后它成功了,诀窍是使用原型和selectBox,然后在底图投影和displayProjection之间应用转换,在本例中是在900913和4326之间。我在这里得到了这个想法:谢谢你的回答和例子。我尝试了第一个代码,它抛出了firebug:
TypeError:this.CLASS\u名称未定义
。我尝试了类名:“OpenLayers.Control.myGetFeature”
下面的返回选项
和selectBox函数之外,但错误仍然存在。在第二个代码中,我一直使用utm(我的底层是utm,层是long/lat)。