OpenLayers Map BoundingBox计算

Question

I'm using the GeoServer to hold some maps, and just a simple OpenLayers app to load and show the data (for now).

I'm successfully loading the demo data (which is in WGS84), but when it comes to my data (which is in Balkans Zone 7, EPSG:31277), when I look at the request, it seems like the BBOX is completely out of order.

I checked the BBOX from the GeoServer preview page (which is made with openLayers) and it looks like this, and works:

http://127.0.0.1:2113/geoserver/GISHome/wms?LAYERS=GISHome%3ANis11Katastar&STYLES=&FORMAT=image%2Fjpeg&SERVICE=WMS&VERSION=1.1.1&REQUEST=GetMap&SRS=EPSG%3A31277&BBOX=7572000,4796000,7574000,4798000&WIDTH=512&HEIGHT=512

The only thing that's different with my request is the BBOX. When copying the BBOX into my request, it works.

http://127.0.0.1:2113/geoserver/wms?LAYERS=Nis11Katastar&FORMAT=image%2Fpng&WIDTH=256&HEIGHT=256&PROJECTION=EPSG%3A31277&SERVICE=WMS&VERSION=1.1.1&REQUEST=GetMap&STYLES=&SRS=EPSG%3A4326&BBOX=-180,-90,0,90

In the GeoServer source, the bounds are somehow calculated and hardcoded. The question is, how? Is there a way not to hardcode them? How should I calculate them. I've tried adding bounds, maxExtent, resolution, I'm obviously missing something more than that here. The GeoServer works fine, I'm using the layers from QuantumGIS.

Ext.onReady(function() {
    var map = new OpenLayers.Map();
    var layer = new OpenLayers.Layer.WMS(
        "Global Imagery",
        "http://127.0.0.1:2113/geoserver/wms",
       {  
        LAYERS:'Nis11Katastar',
        format: 'image/png',
        width:600,
        height:400,
        projection: new OpenLayers.Projection("EPSG:31277"),
        }
    );

Thankyou.

Oh, yes, I'm using GeoExt, but that doesn't change much.

Answer 1

It seems solved. I was setting the right properties, but to the WMS layer object, not to the map object. As for the bounds question, I'm just copying the bounds from the geoserver control panel.