DB视图/表为空时如何避免出现粉红色图块？

从某种意义上说，我有一些空间视图，它们从其他表中选择了一些空间列。该表是使用geoserver发布的。该表是活动的，有时根本没有数据。当表中没有数据时，显示的wms全部都存在，red并且在Firebug控制台中的错误是：

WMS返回：

>  <?xml version="1.0" encoding="UTF-8" standalone="no"?><!DOCTYPE
> ServiceExceptionReport SYSTEM
> "http://192.168.70.65:80/geoserver/schemas/wms/1.1.1/WMS_exception_1_1_1.dtd"> <ServiceExceptionReport version="1.1.1" >   <ServiceException>
>           java.lang.NullPointerException
>     null
>     </ServiceException></ServiceExceptionReport>

编码：

function init(){    
            OpenLayers.IMAGE_RELOAD_ATTEMPTS = 1;
                OpenLayers.Util.onImageLoadErrorColor = "transparent";    

                map = new OpenLayers.Map('map', {   
                    projection: new OpenLayers.Projection("EPSG:900913"),
                    displayProjection: new OpenLayers.Projection("EPSG:4326"),
                    numZoomLevels: 21,
                    maxExtent: new OpenLayers.Bounds(-20037508, -20037508,20037508, 20037508.34),   
                    controls: [
                        new OpenLayers.Control.Navigation(),
                        new OpenLayers.Control.PanZoomBar(),
                        new OpenLayers.Control.LayerSwitcher({'ascending':false}),                       
                        new OpenLayers.Control.ScaleLine(),
                        new OpenLayers.Control.MousePosition(),
                        new OpenLayers.Control.OverviewMap(),
                        new OpenLayers.Control.KeyboardDefaults()
                    ]   


                });

使用GeoExt：

<script src="http://localhost/geoserver/www/ext/adapter/ext/ext-base.js" type="text/javascript"></script>
        <script src="http://localhost/geoserver/www/ext/ext-all.js"  type="text/javascript"></script>
        <link rel="stylesheet" type="text/css" href="http://localhost/geoserver/www/ext/resources/css/ext-all.css"/>

        <link rel="stylesheet" href="http://localhost/geoserver/www/openLayers/theme/default/style.css" type="text/css" />
        <script src="http://localhost/geoserver/www/openLayers/OpenLayers.js" type="text/javascript"></script>

        <script src="http://localhost/geoserver/www/geoext/lib/GeoExt.js" type="text/javascript"></script>        
        <link rel="stylesheet" type="text/css" href="http://localhost/geoserver/www/geoext/resources/css/geoext-all.css"/>


        <script>

            OpenLayers.Util.onImageLoadErrorColor = 1;
            OpenLayers.Util.onImageLoadErrorColor = "transparent";          

            Ext.BLANK_IMAGE_URL = "http://localhost/geoserver/www/ext/resources/images/default/s.gif";
            var app, items = [], controls = [];
            var lon = 85.344;
            var lat = 27.7;
            var zoom = 12;
            var url = "http://localhost/geoserver/wms";



            Ext.onReady(function() {            
                app = new Ext.Viewport({
                    layout: "border",
                    items: items
                });     

您是否尝试过在图像错误上添加一些默认图像的方法：

OpenLayers.Util.onImageLoadError = function(){
     this.src = "images/blank.png";
};

较新版本的OpenLayers（2.11版）应该为此使用CSS类。

.olImageLoadError { 
    /* when OL encounters a 404, don't display the pink image */
    display: none !important;
} 

在OpenLayers中设置以下参数：

// Avoid pink error tiles
OpenLayers.IMAGE_RELOAD_ATTEMPTS = 3;
OpenLayers.Util.onImageLoadErrorColor = "transparent";

参考文件/指南：

http://workshops.opengeo.org/stack-intro/openlayers.html

请注意，对于重新加载尝试恕我直言，3是一个非常高的公差值，可能会降低到仅1。

它对我有用OpenLayers V2.13.1

.olTileImage.olImageLoadError {
    display: none !important;
}