本文基于騰訊課堂老胡的課《跟我學(xué)Openlayers--基礎(chǔ)實例詳解》做的學(xué)習(xí)筆記昭灵，使用的openlayers 5.3.x api。
源碼 見 1040.html 榛瓮，對應(yīng)的 官網(wǎng)示例 https://openlayers.org/en/latest/examples/modify-test.html?q=Modify
https://openlayers.org/en/latest/examples/draw-and-modify-features.html?q=Modify
https://openlayers.org/en/latest/examples/modify-features.html?q=Modify
https://openlayers.org/en/latest/examples/snap.html?q=Modify
image.png
image.png
在修改要素的時候潘悼，是否插入頂點；正則表達式匹配拧烦，若Polygon，則可以增加頂點钝计；該回調(diào)函數(shù)返回值是true 時可以插入頂點恋博；否則不能插入頂點齐佳。
<!DOCTYPE html>
<html>
<head>
<title>要素的修改</title>
<link rel="stylesheet" href="../include/ol.css" type="text/css" />
<script src="../include/ol.js"></script>
</head>
<style>
html,
body,
.map {
margin: 0;
padding: 0;
width: 100%;
height: 95%;
}
</style>
<body>
<div id="map" class="map"></div>
<script>
var styleFunction = (function () {
var styles = {};
var image = new ol.style.Circle({
radius: 5,
fill: null,
stroke: new ol.style.Stroke({ color: 'orange', width: 2 })
});
styles['Point'] = new ol.style.Style({ image: image });
styles['Polygon'] = new ol.style.Style({
stroke: new ol.style.Stroke({
color: 'blue',
width: 3
}),
fill: new ol.style.Fill({
color: 'rgba(0, 0, 255, 0.1)'
})
});
styles['MultiLineString'] = new ol.style.Style({
stroke: new ol.style.Stroke({
color: 'green',
width: 3
})
});
styles['MultiPolygon'] = new ol.style.Style({
stroke: new ol.style.Stroke({
color: 'yellow',
width: 1
}),
fill: new ol.style.Fill({
color: 'rgba(255, 255, 0, 0.1)'
})
});
styles['default'] = new ol.style.Style({
stroke: new ol.style.Stroke({
color: 'red',
width: 3
}),
fill: new ol.style.Fill({
color: 'rgba(255, 0, 0, 0.1)'
}),
image: image
});
return function (feature) {
return styles[feature.getGeometry().getType()] || styles['default'];
};
})();
var geojsonObject = {
'type': 'FeatureCollection',
'crs': {
'type': 'name',
'properties': {
'name': 'EPSG:3857'
}
},
'features': [{
'type': 'Feature',
'geometry': {
'type': 'Point',
'coordinates': [0, 0]
}
}, {
'type': 'Feature',
'geometry': {
'type': 'MultiPoint',
'coordinates': [[-2e6, 0], [0, -2e6]]
}
}, {
'type': 'Feature',
'geometry': {
'type': 'LineString',
'coordinates': [[4e6, -2e6], [8e6, 2e6], [9e6, 2e6]]
}
}, {
'type': 'Feature',
'geometry': {
'type': 'LineString',
'coordinates': [[4e6, -2e6], [8e6, 2e6], [8e6, 3e6]]
}
}, {
'type': 'Feature',
'geometry': {
'type': 'Polygon',
'coordinates': [[[-5e6, -1e6], [-4e6, 1e6],
[-3e6, -1e6], [-5e6, -1e6]], [[-4.5e6, -0.5e6],
[-3.5e6, -0.5e6], [-4e6, 0.5e6], [-4.5e6, -0.5e6]]]
}
}, {
'type': 'Feature',
'geometry': {
'type': 'MultiLineString',
'coordinates': [
[[-1e6, -7.5e5], [-1e6, 7.5e5]],
[[-1e6, -7.5e5], [-1e6, 7.5e5], [-5e5, 0], [-1e6, -7.5e5]],
[[1e6, -7.5e5], [15e5, 0], [15e5, 0], [1e6, 7.5e5]],
[[-7.5e5, -1e6], [7.5e5, -1e6]],
[[-7.5e5, 1e6], [7.5e5, 1e6]]
]
}
}, {
'type': 'Feature',
'geometry': {
'type': 'MultiPolygon',
'coordinates': [
[[[-5e6, 6e6], [-5e6, 8e6], [-3e6, 8e6],
[-3e6, 6e6], [-5e6, 6e6]]],
[[[-3e6, 6e6], [-2e6, 8e6], [0, 8e6],
[0, 6e6], [-3e6, 6e6]]],
[[[1e6, 6e6], [1e6, 8e6], [3e6, 8e6],
[3e6, 6e6], [1e6, 6e6]]]
]
}
}, {
'type': 'Feature',
'geometry': {
'type': 'GeometryCollection',
'geometries': [{
'type': 'LineString',
'coordinates': [[-5e6, -5e6], [0, -5e6]]
}, {
'type': 'Point',
'coordinates': [4e6, -5e6]
}, {
'type': 'Polygon',
'coordinates': [
[[1e6, -6e6], [2e6, -4e6], [3e6, -6e6], [1e6, -6e6]]
]
}]
}
}]
};
var source = new ol.source.Vector({
features: (new ol.format.GeoJSON()).readFeatures(geojsonObject)
});
var layer = new ol.layer.Vector({
source: source,
style: styleFunction
});
//單擊選擇要素后，更改要素的樣式债沮，完成對要素的修改
var overlayStyle = (function () {
var styles = {};
styles['Polygon'] = [
new ol.style.Style({
fill: new ol.style.Fill({
color: [255, 255, 255, 0.5]
})
}),
new ol.style.Style({
stroke: new ol.style.Stroke({
color: [255, 255, 255, 1],
width: 5
})
}),
new ol.style.Style({
stroke: new ol.style.Stroke({
color: [0, 153, 255, 1],
width: 3
})
})
];
styles['MultiPolygon'] = styles['Polygon'];
styles['LineString'] = [
new ol.style.Style({
stroke: new ol.style.Stroke({
color: [255, 255, 255, 1],
width: 5
})
}),
new ol.style.Style({
stroke: new ol.style.Stroke({
color: [0, 153, 255, 1],
width: 3
})
})
];
styles['MultiLineString'] = styles['LineString'];
styles['Point'] = [
new ol.style.Style({
image: new ol.style.Circle({
radius: 7,
fill: new ol.style.Fill({
color: [0, 153, 255, 1]
}),
stroke: new ol.style.Stroke({
color: [255, 255, 255, 0.75],
width: 1.5
})
}),
zIndex: 100000
})
];
styles['MultiPoint'] = styles['Point'];
styles['GeometryCollection'] = styles['Polygon'].concat(styles['Point']);
return function (feature) {
return styles[feature.getGeometry().getType()];
};
})();
var select = new ol.interaction.Select({
style: overlayStyle
});
var modify = new ol.interaction.Modify({
features: select.getFeatures(),
style: overlayStyle,
insertVertexCondition: function () { //在修改要素的時候炼吴，是否插入頂點；正則表達式匹配疫衩，若Polygon硅蹦，則可以增加頂點；該回調(diào)函數(shù)返回值是true 時可以插入頂點闷煤；否則不能插入頂點童芹。
return !select.getFeatures().getArray().every(function (feature) {
return feature.getGeometry().getType().match(/Polygon/);
});
}
});
var map = new ol.Map({
interactions: ol.interaction.defaults().extend([select, modify]),
layers: [layer],
target: 'map',
view: new ol.View({
center: [0, 1000000],
zoom: 2
})
});
</script>
</body>
</html>
