五章-54-绘制要素并修改
2020-04-07 本文已影响0人
彩云飘过
本文基于腾讯课堂老胡的课《跟我学Openlayers--基础实例详解》做的学习笔记，使用的openlayers 5.3.x api。
源码 见 1054.html ，对应的 官网示例
https://openlayers.org/en/latest/examples/draw-and-modify-features.html?q=geometry
https://openlayers.org/en/latest/examples/modify-features.html?q=modi
https://openlayers.org/en/latest/examples/snap.html?q=modi
image.png
image.png
<!DOCTYPE html>
<html>
<head>
<title>绘制要素并修改</title>
<link rel="stylesheet" href="../include/ol.css" type="text/css" />
<script src="../include/ol.js"></script>
</head>
<style></style>
<body>
<form class="form-inline">
<label>几何类型 </label>
<select id="type">
<option value="Point">点</option>
<option value="LineString">线</option>
<option value="Polygon">多边形</option>
<option value="Circle">圆</option>
</select>
</form>
<div id="map" class="map"></div>
<script>
var raster = new ol.layer.Tile({
source: new ol.source.OSM()
});
var source = new ol.source.Vector();
var vector = new ol.layer.Vector({
source: source,
style: new ol.style.Style({
fill: new ol.style.Fill({
color: 'rgba(255, 255, 255, 0.2)'
}),
stroke: new ol.style.Stroke({
color: '#ffcc33',
width: 2
}),
image: new ol.style.Circle({
radius: 7,
fill: new ol.style.Fill({
color: '#ffcc33'
})
})
})
});
var map = new ol.Map({
layers: [raster, vector],
target: 'map',
view: new ol.View({
center: [-11000000, 4600000],
zoom: 4
})
});
var modify = new ol.interaction.Modify({
source: source,
insertVertexCondition: function (){return true} //来控制是否添加新的顶点，
});
map.addInteraction(modify);
var draw, snap;
var typeSelect = document.getElementById('type');
function addInteractions() {
draw = new ol.interaction.Draw({
source: source,
type: typeSelect.value
});
map.addInteraction(draw);
//增加吸附操作，当吸附在要素之后，可以修改要素
snap = new ol.interaction.Snap({ source: source });
map.addInteraction(snap);
}
typeSelect.onchange = function () {
//删除 绘制 和吸附的交互，再重新添加绘制 和吸附操作
map.removeInteraction(draw);
map.removeInteraction(snap);
addInteractions();
};
addInteractions();
</script>
</body>
</html>
