如何在Java中为KmlLayer添加'setPreserveViewport'选项？

Question

我比较新，所以对这个问题可能有一个非常简单的答案，但是如何在Java中为KmlLayer添加'setPreserveViewport'选项？我找到了一个解决方案，但这并不能很好地显示多个KML图层。

所以我现在拥有的是：

    final KmlLayer KMLmap1 = KmlLayer.create("https://earthbuilder.googleusercontent.com/04956359305736194955-05414812628978701557-4/2/kml/link.kml");
    final KmlLayer KMLmap2 = KmlLayer.create("https://dl.dropboxusercontent.com/u/20845226/alledanmarks5regioner.kml");



    class KMLButtonPanel extends FlowPanel {
    public KMLButtonPanel() {
            Button KML1Btn = new Button("KML 1", new ClickHandler() {
              public void onClick(ClickEvent event) {

                  kmlUnload(KMLmap2);

                  kmlLoad(KMLmap1);

              }

            });

            Button KML2Btn = new Button("KML 2", new ClickHandler() {
              public void onClick(ClickEvent event) {

                  kmlUnload(KMLmap1);

                  kmlLoad(KMLmap2);


              }

            });
    }

public void onModuleLoad() {


    private void kmlLoad(KmlLayer layer) {
                layers = layer;
                layers.setMap(map);

        }

      private void kmlUnload(KmlLayer layer) {
                layers = layer;
                layers.setMap(null);
        }
    }

我还有很多其他代码，所以我刚刚复制了相关的行。现在我想做的事情是以某种方式添加setPreserveViewport（true）选项 - 这就是我所处的位置！我怎么做？

Answer 1

对于任何有兴趣的人，解决方案非常简单：

  private KmlLayer layers;

  private String KMLmap1 = "https://earthbuilder.googleusercontent.com/04956359305736194955-05414812628978701557-4/2/kml/link.kml";
  private String KMLmap2 = "https://dl.dropboxusercontent.com/u/20845226/alledanmarks5regioner.kml";

然后当我运行kmlLoad（KMLmap1）;或kmlLoad（KMLmap2）;我明白了：

private void kmlLoad(String string) {

        if (layers != null) {
            kmlUnload();
        }

        KmlLayerOptions layerOpts = KmlLayerOptions.create();
        layerOpts.setPreserveViewport(true);
        KmlLayer newlayers = KmlLayer.create(
                string,
                layerOpts
            );
        layers = newlayers;
        newlayers.setMap(map);

  }

  private void kmlUnload() {
        layers.setMap(null);
    }