Let the map display the range (Swift) based on the callout point

This method in the Baidu map demo bus Search a class of files;

The parameter is a polyline that is connected to all the callout points, which can change the extent of the map display, and show the optimal display scale (pro-test in your own project)

Set the map extent according to Polyline

func mapviewfitpolyline (polyline: bmkpolyline!) {

if polyline. Pointcount < 1 {

return

}

let pt = polyline. Points[0]

var ltX = pt.x

var rbX = pt.x

var lty = pt.y

var rby = pt.y

for i in 1.. <polyline. pointcount {

let pt = polyline. Points[Int(i)]

if pt.x < LtX {

LtX = pt.x

}

if pt.x > RbX {

RbX = pt.x

}

if pt.y > lty {

Lty = pt.y

}

if pt.y < Rby {

Rby = pt.y

}

}

let rect = bmkmaprectmake(LtX, Lty, Rbx-ltx, rby-lty)

Mapview!. visiblemaprect = rect

Mapview!. zoomlevel = mapview!. zoomlevel - 0.3

}

Let the map display the range (Swift) based on the callout point