如何在OpenLayers 3中使笔画不透明度起作用 [英] How to make Stroke opacity work in OpenLayers 3
本文介绍了如何在OpenLayers 3中使笔画不透明度起作用的处理方法,对大家解决问题具有一定的参考价值,需要的朋友们下面随着小编来一起学习吧!
问题描述
无论我做什么,我都无法在OpenLayers 3中使Stroke不透明.我试图达到的目的是在OSM瓷砖贴图上画一条线,透明度为0.5.
这是示例代码:
var lineString = new ol.geom.LineString([
[4.9020, 52.3667],
[4.9030, 52.3667],
[4.9040, 52.3667],
[4.9050, 52.3667]
]);
lineString.transform('EPSG:4326', 'EPSG:3857');
var lineLayer = new ol.layer.Vector({
source: new ol.source.Vector({
features: [new ol.Feature({
geometry: lineString,
name: 'Line'
})]
}),
style: new ol.style.Style({
stroke: new ol.style.Stroke({
color: 'yellow',
opacity: 0.5,
width: 15
})
})
});
var view = new ol.View({
center: ol.proj.transform([4.9020, 52.3667], 'EPSG:4326','EPSG:3857'),
zoom: 18
});
var map = new ol.Map({
layers: [
new ol.layer.Tile({
source: new ol.source.OSM()
}),
lineLayer
],
target: 'map',
controls: ol.control.defaults({
attributionOptions: /** @type {olx.control.AttributionOptions} */ ({
collapsible: false
})
}),
view: view
});
您可以在这里看到它: http://jsfiddle.net/abgcvqw3/1/
解决方案
不透明度是通过color
选项设置的,它是颜色值的第四个元素(A,代表RGBA中的"Alpha").>
例如,以下是您可以使用半透明黄色的方法:
color: [255, 255, 0, 0.5]
这是另一种表示法:
color: 'rgba(255,255,0,0.5)'
I cannot get Stroke opacity working in OpenLayers 3 no matter what I try. What I try to achieve is to draw a line to OSM tile map with 0.5 opacity.
Here is sample code:
var lineString = new ol.geom.LineString([
[4.9020, 52.3667],
[4.9030, 52.3667],
[4.9040, 52.3667],
[4.9050, 52.3667]
]);
lineString.transform('EPSG:4326', 'EPSG:3857');
var lineLayer = new ol.layer.Vector({
source: new ol.source.Vector({
features: [new ol.Feature({
geometry: lineString,
name: 'Line'
})]
}),
style: new ol.style.Style({
stroke: new ol.style.Stroke({
color: 'yellow',
opacity: 0.5,
width: 15
})
})
});
var view = new ol.View({
center: ol.proj.transform([4.9020, 52.3667], 'EPSG:4326','EPSG:3857'),
zoom: 18
});
var map = new ol.Map({
layers: [
new ol.layer.Tile({
source: new ol.source.OSM()
}),
lineLayer
],
target: 'map',
controls: ol.control.defaults({
attributionOptions: /** @type {olx.control.AttributionOptions} */ ({
collapsible: false
})
}),
view: view
});
You can see it here: http://jsfiddle.net/abgcvqw3/1/
解决方案
The opacity is set through the color
option, as the fourth element of the color value (the A, for "Alpha" in RGBA).
For example here's how you can have a semi transparent yellow:
color: [255, 255, 0, 0.5]
And here is another notation:
color: 'rgba(255,255,0,0.5)'
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