風格：Openlayers中的顏色和筆觸寬度？

Question

我試過一些方法，但似乎找不到合適的方法，
如何為此圖層添加樣式：

        var line_1 = new OpenLayers.Layer.Vector("Line nr 1", {
            projection: map.displayProjection,
            strategies: [new OpenLayers.Strategy.Fixed()],
            protocol: new OpenLayers.Protocol.HTTP({
                url: "lines/line_1.kml",
                format: newOpenLayers.Format.KML({
                    extractStyles: true,
                    extractAttributes: true
                })
            })
        });

就像下面的層一樣：

            var line_1 = new OpenLayers.Layer.GML('Line nr - 1', 
                    "lines/line_1.kml",
                    {
                            visibility: true,
                            format: OpenLayers.Format.KML,
                            style: {strokeWidth: 4, strokeColor: "#ff0000", strokeOpacity: 1 },
                            projection: map.displayProjection,
                            strategies: [new OpenLayers.Strategy.Fixed()]
                    }
            );

差異在於第一個變量Im使用Vector和第二個GML
我仍然是這個東西的初學者，任何幫助將非常感激。

Answer 1

您可以像這樣定義樣式：

var style = OpenLayers.Util.extend({}, OpenLayers.Feature.Vector.style['default']);
style.fillOpacity = 0.2;
style.graphicOpacity = 1;
style.strokeWidth = 4; 
style.strokeColor = "#ff0000";
style.strokeOpacity = 1;

然后在創建Vector圖層時將其傳遞給選項：

var line_1 = new OpenLayers.Layer.Vector("Line nr 1", {
            style : style,
            projection: map.displayProjection,
            strategies: [new OpenLayers.Strategy.Fixed()],
            protocol: new OpenLayers.Protocol.HTTP({
                url: "lines/line_1.kml",
                format: newOpenLayers.Format.KML({
                    extractStyles: true,
                    extractAttributes: true
                })
            })
        });