官方标配写法：
import L from 'leaflet';
import FreeDraw from 'leaflet-freedraw';
const map = new L.Map(node);
const freeDraw = new FreeDraw();
map.addLayer(freeDraw);复制代码绘画操作函数：
freeDraw.on('markers', event => {
console.log(event.latLngs); // 返回所有多边形坐标
});复制代码那么返回最新画的多边形坐标，咋整？
var latestPolygon = eventData.latLngs.filter(function (latLngs) {
const json = JSON.stringify(latLngs)
const has = !~seenPolygons.indexOf(json)
has && seenPolygons.push(json)
return has
}) // latestPolygon 就是最新的这个多边形坐标复制代码画笔的功能 和 一些默认值
| Option | Default | Result |
|---|---|---|
mode |
ALL |
Modifies the default mode. |
smoothFactor |
0.3 |
By how much to smooth the polygons. |
elbowDistance |
10 |
Factor to determine when to delete or when to append an edge. |
simplifyFactor |
1.1 |
By how much to simplify the polygon. |
mergePolygons |
true |
Whether to attempt merging of polygons that intersect. |
concavePolygon |
true |
Whether to apply the concaving algorithm to the polygons. |
maximumPolygons |
Infinity |
Maximum number of polygons to be added to the map layer. |
recreateAfterEdit |
false |
Whether to recreate the polygons subsequent to them being modified. |
notifyAfterEditExit |
false |
Whether to defer markers event until after exiting EDIT mode. |
leaveModeAfterCreate |
false |
Whether to exit CREATE mode after each polygon creation. |
strokeWidth |
2 |
Size of the stroke when drawing. |
指定画笔有哪些功能，咋整？
// Allow create, edit and delete.
freeDraw.mode(CREATE | EDIT | DELETE);
// Allow everything except create.
freeDraw.mode(ALL ^ CREATE);
// Allow nothing.
freeDraw.mode(NONE);复制代码各种方法函数 ：
| Method | Yields | Result |
|---|---|---|
create |
Array |
Creates a polygon by passing an array of LatLngs |
remove |
void |
Removes a polygon that is yielded from create |
clear |
void |
Clears all polygons from the current instance |
mode |
Number |
Sets and retrieves the current mode. |
cancel |
void |
Cancels the current create action – such as on escape. |
size |
Number |
Yields the number of polygons on the map layer. |
all |
Array |
Enumerate all of the current polygons for the current layer |
备注：
单击多边形 可以 删掉
