Google Maps API v3会在点击标记上添加阴影

Question

我知道正式google删除了谷歌地图API v3中标记的阴影。考虑到这一点，我有一个需要标记阴影的项目。单击标记时，我想在标记上放置阴影。它本质上是为一个标记添加一个事件监听器，当它被点击时，为标记添加一个阴影，作为一种方式来显示被点击的标记是活动标记。

我读了一些页面，例如marker shadows in google maps v3将阴影放在所有标记上，但我想借用这样一个例子并在点击标记时添加阴影并在标记失去焦点时删除阴影，即点击另一个标记时。

我的jsfiddle有两个标记可供使用，代码如下：jsfiddle is here

var marker;
var locations = [["6","43.683","9.58","3002: Location 1",1],["7","45.149","9.44","3003: Location",2]];
function initialize() {
    var mapProp = {
    center: new google.maps.LatLng(43.683, 9.44),
    zoom: 5,
    mapTypeId: google.maps.MapTypeId.ROADMAP};

    var map = new google.maps.Map(document.getElementById("googleMap"), mapProp);
        for (i = 0; i < locations.length; i++) {
        marker = new google.maps.Marker({
        position:new google.maps.LatLng(locations[i][1], locations[i][2]),
        icon:'https://maps.gstatic.com/mapfiles/ms2/micons/purple.png',
    });

    google.maps.event.addListener(marker, 'click', (function(marker, i) {
        return function() {
            alert(locations[i][3] + " was clicked");
        }
    })(marker, i));

    marker.setMap(map);
    }
}

google.maps.event.addDomListener(window, 'load', initialize);

如果有人可以帮助我制定一个策略甚至是一个代码片段，当它被点击时在标记上放置阴影我会非常高兴。请随意分叉jsfiddle并添加到它并在此处发布链接。

Answer 1

另一个选项，在第一次点击标记时创建标记阴影对象（来自我对你引用的问题的回答），点击标记时将其移动到新点击的标记（添加.setPosition方法MarkerShadow类。）

var marker;
var locations = [
  ["6", "43.683", "9.58", "3002: Location 1", 1, true],
  ["7", "45.149", "9.44", "3003: Location", 2, false]
];
var markerShadow;
var infowindow = new google.maps.InfoWindow();

function initialize() {
  var mapProp = {
    center: new google.maps.LatLng(43.683, 9.44),
    zoom: 5,
    mapTypeId: google.maps.MapTypeId.ROADMAP
  };

  var map = new google.maps.Map(document.getElementById("googleMap"), mapProp);
  var iconShadow = {
    url: 'http://www.geocodezip.com/mapIcons/marker_shadow.png',
    // The shadow image is larger in the horizontal dimension
    // while the position and offset are the same as for the main image.
    size: new google.maps.Size(37, 34),
    origin: new google.maps.Point(0, 0),
    anchor: new google.maps.Point(10, 34)
  };


  for (i = 0; i < locations.length; i++) {
    marker = new google.maps.Marker({
      position: new google.maps.LatLng(locations[i][1], locations[i][2]),
      icon: 'https://maps.gstatic.com/mapfiles/ms2/micons/purple.png',
      title: locations[i][3]
    });
    google.maps.event.addListener(marker, 'click', (function(marker, i) {
      return function() {
        if (markerShadow && markerShadow.setPosition) {
          markerShadow.setPosition(this.getPosition());
        } else if (!markerShadow) {
          markerShadow = new MarkerShadow(marker.getPosition(), iconShadow, map);
        }
      }
    })(marker, i));

    marker.setMap(map);
  }
}

google.maps.event.addDomListener(window, 'load', initialize);

// marker shadow code
MarkerShadow.prototype = new google.maps.OverlayView();
MarkerShadow.prototype.setPosition = function(latlng) {
    this.posn_ = latlng;
    this.draw();
  }
  /** @constructor */

function MarkerShadow(position, options, map) {

    // Initialize all properties.
    this.posn_ = position;
    this.map_ = map;
    if (typeof(options) == "string") {
      this.image = options;
    } else {
      this.options_ = options;
      if (!!options.size) this.size_ = options.size;
      if (!!options.url) this.image_ = options.url;
    }

    // Define a property to hold the image's div. We'll
    // actually create this div upon receipt of the onAdd()
    // method so we'll leave it null for now.
    this.div_ = null;

    // Explicitly call setMap on this overlay.
    this.setMap(map);
  }
  /**
   * onAdd is called when the map's panes are ready and the overlay has been
   * added to the map.
   */
MarkerShadow.prototype.onAdd = function() {
  // if no url, return, nothing to do.
  if (!this.image_) return;
  var div = document.createElement('div');
  div.style.borderStyle = 'none';
  div.style.borderWidth = '0px';
  div.style.position = 'absolute';

  // Create the img element and attach it to the div.
  var img = document.createElement('img');
  img.src = this.image_;
  img.style.width = this.options_.size.x + 'px';
  img.style.height = this.options_.size.y + 'px';
  img.style.position = 'absolute';
  div.appendChild(img);

  this.div_ = div;

  // Add the element to the "overlayLayer" pane.
  var panes = this.getPanes();
  panes.overlayShadow.appendChild(div);
};

MarkerShadow.prototype.draw = function() {
  // if no url, return, nothing to do.
  if (!this.image_) return;
  // We use the coordinates of the overlay to peg it to the correct position 
  // To do this, we need to retrieve the projection from the overlay.
  var overlayProjection = this.getProjection();

  var posn = overlayProjection.fromLatLngToDivPixel(this.posn_);

  // Resize the image's div to fit the indicated dimensions.
  if (!this.div_) return;
  var div = this.div_;
  if (!!this.options_.anchor) {
    div.style.left = Math.floor(posn.x - this.options_.anchor.x) + 'px';
    div.style.top = Math.floor(posn.y - this.options_.anchor.y) + 'px';
  }
  if (!!this.options_.size) {
    div.style.width = this.size_.x + 'px';
    div.style.height = this.size_.y + 'px';
  }
};

// The onRemove() method will be called automatically from the API if
// we ever set the overlay's map property to 'null'.
MarkerShadow.prototype.onRemove = function() {
  if (!this.div_) return;
  this.div_.parentNode.removeChild(this.div_);
  this.div_ = null;
};

html,
body,
#googleMap {
  height: 100%;
  width: 100%;
  margin: 0px;
  padding: 0px
}

<script src="https://maps.googleapis.com/maps/api/js"></script>
<div id="googleMap"></div>

fiddle showing result