OpenLayers3基础教程——OL3之Popup

概述：

本节重点讲述OpenLayers3中Popup的调用时实现，OL3改用Overlay代替OL2的Popup功能。

接口简介：

overlay跟ol.control.Control一样，是一个可见的窗口，但是不和Control一样，不是固定在地图区域的某个部分，而是显示在一个地图坐标上，随着地图的移动或者缩放而移动的。其调用方式如下：

var popup = new ol.Overlay({
  element: document.getElementById('popup')
});
popup.setPosition(coordinate);
map.addOverlay(popup);

Extends

• ol.Object

Observable Properties

Name	Type	Settable	ol.ObjectEvent type	Description
element	Element | undefined	yes	change:element	The Element containing the overlay.
map	ol.Map | undefined	yes	change:map	The map that the overlay is part of.
offset	Array.<number>	yes	change:offset	The offset.
position	ol.Coordinate | undefined	yes	change:position	The spatial point that the overlay is anchored at.
positioning	ol.OverlayPositioning	yes	change:positioning	How the overlay is positioned relative to its point on the map.

Methods

Returns:

The Element containing the overlay. 

Returns:

The map that the overlay is part of. 

Returns:

The offset. 

Returns:

The spatial point that the overlay is anchored at. 

Returns:

How the overlay is positioned relative to its point on the map. 

Name	Type	Description
type	string | Array.<string>	The event type or array of event types.
listener	function	The listener function.
this	Object	The object to use as this in listener.

Returns:

Unique key for the listener. 

Name	Type	Description
type	string | Array.<string>	The event type or array of event types.
listener	function	The listener function.
this	Object	The object to use as this in listener.

Returns:

Unique key for the listener. 

Name	Type	Description
element	Element | undefined	The Element containing the overlay.

Name	Type	Description
map	ol.Map | undefined	The map that the overlay is part of.

Name	Type	Description
offset	Array.<number>	Offset.

Name	Type	Description
position	ol.Coordinate | undefined	The spatial point that the overlay is anchored at.

Name	Type	Description
positioning	ol.OverlayPositioning	how the overlay is positioned relative to its point on the map.

Name	Type	Description
type	string | Array.<string>	The event type or array of event types.
listener	function	The listener function.
this	Object	The object which was used as this by the listener.

Name	Type	Description
key	goog.events.Key	Key.

上面的内容是OL3 的API中关于overlay的部分。

调用示例：

1、popup样式

		body, #map {
			border: 0px;
			margin: 0px;
			padding: 0px;
			width: 100%;
			height: 100%;
			font-size: 13px;
		}

		.ol-popup {
			display: none;
			position: absolute;
			background-color: white;
			-moz-box-shadow: 0 1px 4px rgba(0,0,0,0.2);
			-webkit-filter: drop-shadow(0 1px 4px rgba(0,0,0,0.2));
			filter: drop-shadow(0 1px 4px rgba(0,0,0,0.2));
			border: 1px solid #cccccc;
			bottom: 12px;
			left: -50px;
			width: 200px;
		}
		.ol-popup:after, .ol-popup:before {
			top: 100%;
			border: solid transparent;
			content: " ";
			height: 0;
			width: 0;
			position: absolute;
			pointer-events: none;
		}
		.ol-popup:after {
			border-top-color: white;
			border-width: 10px;
			left: 48px;
			margin-left: -10px;
		}
		.ol-popup:before {
			border-top-color: #cccccc;
			border-width: 11px;
			left: 48px;
			margin-left: -11px;
		}
		.popup-title{
			font-weight: bold;
			border-bottom:1px solid #cccccc;
			padding: 5px 8px;
		}
		.popup-content{
			padding: 5px 8px;
		}
		.ol-popup-closer {
			text-decoration: none;
			position: absolute;
			top: 6px;
			right: 6px;
		}
		.ol-popup-closer:after {
			content: "✖";
		}

2、popup容器

<div id="map">
	<div id="popup" class="ol-popup">
		<a href="#" id="popup-closer" class="ol-popup-closer"></a>
		<div id="popup-title" class="popup-title"></div>
		<div id="popup-content" class="popup-content"></div>
	</div>
</div>

3、实现js

			var container = document.getElementById('popup');
			var content = document.getElementById('popup-content');
			var title = document.getElementById('popup-title');
			var closer = document.getElementById('popup-closer');
			closer.onclick = function(){
				container.style.display = 'none';
				closer.blur();
				return false;
			};
			var overlay = new ol.Overlay({
				element: container
			});
			map.addOverlay(overlay);

			map.on('click', function(evt) {
				var coordinate = evt.coordinate;
				var hdms = ol.coordinate.toStringHDMS(ol.proj.transform(
						coordinate, 'EPSG:4326', 'EPSG:4326'));
				overlay.setPosition(coordinate);
				content.innerHTML = '<p>You clicked here:</p><code>' + hdms +
				'</code>';
				container.style.display = 'block';
				title.innerHTML = "提示信息";
				title.style.display = 'block';
				map.getView().setCenter(coordinate);
			});

示例完整代码如下：

<html xmlns="http://www.w3.org/1999/xhtml">
<head>
	<meta http-equiv="Content-Type" content="text/html; charset=utf-8" />
	<title>Ol3 popup</title>
	<link rel="stylesheet" type="text/css" href="http://localhost/ol3/css/ol.css"/>
	<style type="text/css">
		body, #map {
			border: 0px;
			margin: 0px;
			padding: 0px;
			width: 100%;
			height: 100%;
			font-size: 13px;
		}

		.ol-popup {
			display: none;
			position: absolute;
			background-color: white;
			-moz-box-shadow: 0 1px 4px rgba(0,0,0,0.2);
			-webkit-filter: drop-shadow(0 1px 4px rgba(0,0,0,0.2));
			filter: drop-shadow(0 1px 4px rgba(0,0,0,0.2));
			border: 1px solid #cccccc;
			bottom: 12px;
			left: -50px;
			width: 200px;
		}
		.ol-popup:after, .ol-popup:before {
			top: 100%;
			border: solid transparent;
			content: " ";
			height: 0;
			width: 0;
			position: absolute;
			pointer-events: none;
		}
		.ol-popup:after {
			border-top-color: white;
			border-width: 10px;
			left: 48px;
			margin-left: -10px;
		}
		.ol-popup:before {
			border-top-color: #cccccc;
			border-width: 11px;
			left: 48px;
			margin-left: -11px;
		}
		.popup-title{
			font-weight: bold;
			border-bottom:1px solid #cccccc;
			padding: 5px 8px;
		}
		.popup-content{
			padding: 5px 8px;
		}
		.ol-popup-closer {
			text-decoration: none;
			position: absolute;
			top: 6px;
			right: 6px;
		}
		.ol-popup-closer:after {
			content: "✖";
		}
	</style>
	<script type="text/javascript" src="http://localhost/ol3/build/ol.js"></script>
	<script type="text/javascript" src="http://localhost/jquery/jquery-1.8.3.js"></script>
	<script type="text/javascript">
		function init(){
			var format = 'image/png';
			var bounds = [73.4510046356223, 18.1632471876417,
				134.976797646506, 53.5319431522236];
			var untiled = new ol.layer.Image({
				source: new ol.source.ImageWMS({
					ratio: 1,
					url: 'http://localhost:8081/geoserver/lzugis/wms',
					params: {'FORMAT': format,
						'VERSION': '1.1.1',
						LAYERS: 'lzugis:capital',
						STYLES: ''
					}
				})
			});
			var projection = new ol.proj.Projection({
				code: 'EPSG:4326',
				units: 'degrees'
			});
			var container = document.getElementById('popup');
			var content = document.getElementById('popup-content');
			var title = document.getElementById('popup-title');
			var closer = document.getElementById('popup-closer');
			closer.onclick = function(){
				container.style.display = 'none';
				closer.blur();
				return false;
			};
			var overlay = new ol.Overlay({
				element: container
			});
			map.addOverlay(overlay);

			var map = new ol.Map({
				controls: ol.control.defaults({
					attribution: false
				}),
				target: 'map',
				layers: [untiled],
				overlays: [overlay],
				view: new ol.View({
					projection: projection
				})
			});
			map.getView().fitExtent(bounds, map.getSize());

			map.on('click', function(evt) {
				var coordinate = evt.coordinate;
				var hdms = ol.coordinate.toStringHDMS(ol.proj.transform(
						coordinate, 'EPSG:4326', 'EPSG:4326'));
				overlay.setPosition(coordinate);
				content.innerHTML = '<p>You clicked here:</p><code>' + hdms +
				'</code>';
				container.style.display = 'block';
				title.innerHTML = "提示信息";
				title.style.display = 'block';
				map.getView().setCenter(coordinate);
			});
		}
	</script>
</head>
<body onLoad="init()">
<div id="map">
	<div id="popup" class="ol-popup">
		<a href="#" id="popup-closer" class="ol-popup-closer"></a>
		<div id="popup-title" class="popup-title"></div>
		<div id="popup-content" class="popup-content"></div>
	</div>
</div>
</body>
</html>

实现后的效果如下：

相关文章：

OpenLayers3基础教程——OL3基本概念

OpenLayers3基础教程——加载资源

OpenLayers3基础教程——OL3 介绍control

转载自：https://blog.csdn.net/GISShiXiSheng/article/details/46794813