问题描述
This example在按下按钮时显示绘图功能。它允许您选择不同的形状,例如点,线,多边形等。我想将类似的功能合并到我的项目中。但是我不想选择形状,而是想按下按钮来打开绘制点,线,多边形等的功能。
我认为应该在HTML部分中插入按钮元素。
<select id="type">
<option value="Point">Point</option>
<option value="Linestring">Linestring</option>
<option value="polygon">polygon</option>
<option value="Circle">Circle</option>
<option value="None">None</option>
</select>
我尝试如下。
</div>
<div id="type">
<button value="Point">button1</button>
<button value="polygon">button2</button>
<button value="Linestring">button3</button>
</div>
在我看来,脚本中也需要进行一些更改。
var typeSelect = document.getElementById('type');
var draw; // global so we can remove it later
function addInteraction() {
var value = typeSelect.value;
if (value !== 'None') {
draw = new Draw({
source: source,type: typeSelect.value,});
map.addInteraction(draw);
}
}
有人可以帮我吗?
解决方法
- 将选择更改为按钮。
<div id="type">
<button id="Point" value="Point">Point</button>
<button id="Polygon" value="Polygon">Polygon</button>
<button id="LineString" value="LineString">LineString</button>
<button id="None" value="None">None</button>
</div>
- 在每个按钮上添加一个点击侦听器,以适当地设置交互
/**
* Handle button clicks.
*/
function handleBtnClick() {
var element=this;
map.removeInteraction(draw);
addInteraction(element);
};
document.getElementById("Point").addEventListener('click',handleBtnClick);
document.getElementById("Polygon").addEventListener('click',handleBtnClick);
document.getElementById("LineString").addEventListener('click',handleBtnClick);
document.getElementById("None").addEventListener('click',handleBtnClick);
代码段:
var raster = new ol.layer.Tile({ // TileLayer({
source: new ol.source.OSM(),});
var source = new ol.source.Vector({ // VectorSource({
wrapX: false
});
var vector = new ol.layer.Vector({ // VectorLayer({
source: source,});
var map = new ol.Map({
layers: [raster,vector],target: 'map',view: new ol.View({
center: [-11000000,4600000],zoom: 4,}),});
var typeSelect = document.getElementById('type');
var draw; // global so we can remove it later
function addInteraction(element) {
var value = element.value;
if (value !== 'None') {
draw = new ol.interaction.Draw({
source: source,type: value,});
map.addInteraction(draw);
}
}
/**
* Handle button clicks.
*/
function handleBtnClick() {
var element = this;
map.removeInteraction(draw);
addInteraction(element);
// return false;
};
document.getElementById("Point").addEventListener('click',handleBtnClick);
document.getElementById("Polygon").addEventListener('click',handleBtnClick);
document.getElementById("LineString").addEventListener('click',handleBtnClick);
document.getElementById("None").addEventListener('click',handleBtnClick);
addInteraction(document.getElementById('None'));
html,body {
height: 100%;
width: 100%;
padding: 0px;
margin: 0px;
}
.map {
height: 90%;
width: 100%;
}
<title>Draw Features</title>
<link rel="stylesheet" href="https://openlayers.org/en/v6.4.3/css/ol.css" type="text/css">
<!-- Pointer events polyfill for old browsers,see https://caniuse.com/#feat=pointer -->
<script src="https://unpkg.com/elm-pep"></script>
<script src="https://cdn.jsdelivr.net/gh/openlayers/openlayers.github.io@master/en/v6.4.3/build/ol.js"></script>
<div id="map" class="map"></div>
<label>Geometry type </label>
<div id="type">
<button id="Point" value="Point">Point</button>
<button id="Polygon" value="Polygon">Polygon</button>
<button id="LineString" value="LineString">LineString</button>
<button id="None" value="None">None</button>
</div>