不能在Seadragon中创建多个覆盖

我正试图在我正在制作的海龙地图上添加套印格式,但由于某些原因,我无法计算出我们的海龙忽略了除第一个套印格式以外的所有套印格式。对此任何帮助都非常感谢。

var viewer = null;

function init() {
    Seadragon.Config.autoHideControls = false;

    viewer = new Seadragon.Viewer("container");

    viewer.addEventListener("open", addOverlays);

    viewer.addControl(makeControl(), Seadragon.ControlAnchor.TOP_RIGHT);

    $(viewer.getNavControl()).parent().parent().css({ 'top': 10, 'right': 10 });
    viewer.openDzi("_assets/Mapdata/dzc_output.xml");

}

function makeControl() {
    var control = document.createElement("a");
    var controlText = document.createTextNode("");

    control.href = "#"; // so browser shows it as link
    control.className = "control";
    control.appendChild(controlText);

    Seadragon.Utils.addEvent(control, "click",
                    onControlClick);

    return control;
}

function onControlClick(event) {
    Seadragon.Utils.cancelEvent(event); // don't process link

    if (!viewer.isOpen()) {
        return;
    }

    // These are the coordinates of europe on this map
    var x = 0.5398693914203284;
    var y = 0.21155952391206562;
    var z = 5;

    viewer.viewport.panTo(new Seadragon.Point(x, y));
    viewer.viewport.zoomTo(z);
    viewer.viewport.ensureVisible();
}

function addOverlays(viewer) {
    drawer = viewer.drawer;
    var img = document.createElement("img");
    img.src = "_assets/Images/pushpin.png";

    $(img).addClass('pushPin');

    var overlays = [
        { elmt: img, point: new Seadragon.Point(0.51, 0.22) },
        { elmt: img, point: new Seadragon.Point(0.20, 0.13) }
    ];

    for (var i = 0; i < overlays.length; i++) {
        drawer.addOverlay(overlays[i].elmt, overlays[i].point);
    }


}

Seadragon.Utils.addEvent(window, "load", init);