iOS高德地圖WMS服務&Mapbox地圖WMS服務

時間 2020-05-23

標籤 ios 地圖 wms 服務 mapbox 欄目 iOS 简体版

原文原文鏈接

網絡地圖服務（WMS）

網絡地圖服務（WMS）利用具備地理空間位置信息的數據製做地圖。其中將地圖定義爲地理數據可視的表現。可以根據用戶的請求返回相應的地圖（包括PNG，GIF，JPEG等柵格形式或者是SVG和WEB CGM等矢量形式）。WMS支持網絡協議HTTP，所支持的操做是由URL定義的。ios

先來分析一波服務連接：
通常狀況給咱們的是這樣的：http://... .../geoserver/xf/wms?service=WMS&version=1.1.0&request=GetMap&layers=zgwz_lzyz_f08&styles=&bbox=-1844.9489742784644,0.0,35699.99999999942,34437.74999999997&width=768&height=704&srs=EPSG:3857&format=application/openlayersgit

參數：api

service=WMS
version=1.1.0 ：版本（1.1...和1.3...在計算上有區別）
request=GetMap
layers=zgwz_lzyz_f08 ：圖層數組（這個參數若是錯誤則不顯示）
styles=
bbox=-1844.9489742784644,0.0,35699.99999999942,34437.74999999997 : 盒子（顯示區域）通常是須要計算
width=768
height=704
srs=EPSG:3857 ：座標類型：3857同900913爲僞墨卡託投影，也被稱爲球體墨卡託座標；4326爲WGS84經緯度座標
format=application/openlayers ：格式，iOS用這個format=image/png
TRANSPARENT=TRUE ：透明 true：能夠看到高德底圖，false看不到高德底圖
==>**http://... .../geoserver/xf/wms?SERVICE=WMS&VERSION=1.1.0&REQUEST=GetMap&LAYERS=zgwz_lzyz_f08_gd&TRANSPARENT=TRUE&STYLES=&WIDTH=762&HEIGHT=768&srs=EPSG:3857&FORMAT=image/png&BBOX=

1、高德地圖:

經過高德地圖 MATileOverlay 接口，添加 WMS 服務到地圖上數組

1.自定義類WMSTileOverlay繼承自MATileOverlay

import UIKit

class WMSTileOverlay: MATileOverlay {
    var rootURL = ""
    var titleSize = 0
    var initialResolution = 0.0
    var originShift = 0.0
    var HALF_PI = 0.0
    var RAD_PER_DEGREE = 0.0
    var HALF_RAD_PER_DEGREE = 0.0
    var METER_PER_DEGREE = 0.0
    var DEGREE_PER_METER = 0.0
    
    /// 初始化
    /// - Parameter initRootURL: 在線地圖路徑&TRANSPARENT=TRUE&FORMAT=image/png&BBOX=
    init?(rootURL initRootURL: String?) {
        super.init()
        rootURL = initRootURL ?? ""
        titleSize = 256
        initialResolution = 156543.03392804062////2*Math.PI*6378137/titleSize
        originShift = 20037508.342789244//周長的一半 2*Math.PI*6378137/2.0
        HALF_PI = .pi / 2.0
        RAD_PER_DEGREE = .pi/180.0
        HALF_RAD_PER_DEGREE = .pi/360.0
        METER_PER_DEGREE = originShift/180.0//一度多少米
        DEGREE_PER_METER = 180.0/originShift//一米多少度
    }
    
    /**
     * @brief 以tile path生成URL。用於加載tile,此方法默認填充URLTemplate
     * @param path tile path
     * @return 以tile path生成tileOverlay
     */
    override func url(forTilePath path: MATileOverlayPath) -> URL {
        
        let strURL = "\(rootURL)\(titleBoundsBy(x: path.x, y: path.y, zoom: path.z) ?? "")"
        let url = URL(string: strURL)
        return url!
    }
    
    /**
     * @brief 加載被請求的tile,並以tile數據或加載tile失敗error訪問回調block;默認實現爲首先用URLForTilePath去獲取URL,而後用異步NSURLConnection加載tile
     * @param path tile path
     * @param result 用來傳入tile數據或加載tile失敗的error訪問的回調block
     */
    override func loadTile(at path: MATileOverlayPath, result: @escaping(Data?, Error?) -> Void) {
        let url = self.url(forTilePath: path)
        let request = NSMutableURLRequest(url: url)
        request.httpMethod = "GET"
        let session = URLSession.shared
        session.dataTask(with: request as URLRequest, completionHandler: {(data, response, error) in
            if error != nil {
                #if DEBUG
                print("Error downloading tile")
                #endif
                result(nil, error)
            }
            else {
                result(data, nil)
            }
        }).resume()
    }
    
    /// 取消請求瓦片，當地圖顯示區域發生變化時，會取消顯示區域外的瓦片的下載, 當disableOffScreenTileLoading=YES時會被調用。since 5.3.0
    /// - Parameter path: path
    override func cancelLoadOfTile(at path: MATileOverlayPath) {
        super.cancelLoadOfTile(at: path)
    }
    
    /**
     * 根據瓦片的x/y等級返回瓦片範圍
     *
     * @param tx
     * @param ty
     * @param zoom
     * @return url
     */
    func titleBoundsBy(x: Int, y: Int, zoom: Int) -> String? {
        let minX = pixels2Meters(x * titleSize, zoom: zoom)
        let maxY = -pixels2Meters(y * titleSize, zoom: zoom)
        let maxX = pixels2Meters(((x + 1) * titleSize), zoom: zoom)
        let minY = -pixels2Meters(((y + 1) * titleSize), zoom: zoom)
        
        return "\(minX),\(minY),\(maxX),\(maxY)"
    }
    
    /**
     * 根據像素、等級算出座標
     *
     * @param p p
     * @param zoom z
     * @return double
     */
    func pixels2Meters(_ p: Int, zoom: Int) -> Double {
        return Double(p) * resolution(zoom) - originShift
    }
    
    /**
     * 計算分辨率
     *
     * @param zoom z
     * @return double
     */
    func resolution(_ zoom: Int) -> Double {
        return initialResolution / (pow(2.0, Double(zoom)))
    }
}

2.在地圖控制器MapController調用

import UIKit
class MapController: UIViewController {
    let tileOverlay = WMSTileOverlay.init(rootURL: "http://... .../geoserver/haitu/wms?SERVICE=WMS&VERSION=1.1.0&REQUEST=GetMap&LAYERS=haitu:gis_t_landuse_a&TRANSPARENT=TRUE&STYLES=&srs=EPSG:3857&FORMAT=image/png&BBOX=")
    
    override func viewDidLoad() {
        super.viewDidLoad()
        let map = MAMapView(frame: frame: view.bounds)
        mapView.autoresizingMask = [.flexibleWidth, .flexibleHeight]
        mapView.setCenter(CLLocationCoordinate2D(latitude: 39.97000000, longitude: 116.3300000), zoomLevel: 20, animated: false)
        tileOverlay?.disableOffScreenTileLoading = true//中止不在顯示區域的瓦片下載
        mapView.add(tileOverlay)
        view.addSubview(mapView)
    }
}

3.異常處理

（1）WMS服務地圖沒有座標：會致使圖層不能顯示在正確的位置，這時候圖層會顯示在地圖的（0，0）座標位置（非洲），排查的方法就是將地圖中心設置在（0，0）座標，而後放大。解決辦法就是製圖工程師給你個帶座標的圖。緩存

（2）圖層疊加了不少次：第一齣現這種狀況有多是咱們本身對圖層作的緩存引發的。能夠刪除緩存試試。網絡

（3）出現柵格：這種狀況有可能發佈的圖有問題，或者bbox參數計算出現了問題。出現這種狀況的緣由不少，歡迎補充。session

（4）座標系不一樣、WMS版本1.1和1.3：若是WMS服務給的是84座標系，疊加到高德上會出現偏移，可讓製圖工程師出一個高德座標系的圖，也能夠咱們本身在代碼裏作，會有一點計算量，代碼以下：app

在第1步自定義類WMSTileOverlay中的方法func titleBoundsBy(x: Int, y: Int, zoom: Int) -> String?更改異步

/**
 * 根據瓦片的x/y等級返回瓦片範圍
 *
 * @param tx
 * @param ty
 * @param zoom
 * @return url
 */
func titleBoundsBy(x: Int, y: Int, zoom: Int) -> String? {
    let minX = pixels2Meters(x * titleSize, zoom: zoom)
    let maxY = -pixels2Meters(y * titleSize, zoom: zoom)
    let maxX = pixels2Meters(((x + 1) * titleSize), zoom: zoom)
    let minY = -pixels2Meters(((y + 1) * titleSize), zoom: zoom)
    
    return "\(minX),\(minY),\(maxX),\(maxY)"
}

改成ide

/**
 * 根據瓦片的x/y等級返回瓦片範圍
 *
 * @param tx
 * @param ty
 * @param zoom
 * @return url
 */
func titleBoundsBy(x: Int, y: Int, zoom: Int) -> String? {
    var minX = pixels2Meters(x * titleSize, zoom: zoom)
    var maxY = -pixels2Meters(y * titleSize, zoom: zoom)
    var maxX = pixels2Meters(((x + 1) * titleSize), zoom: zoom)
    var minY = -pixels2Meters(((y + 1) * titleSize), zoom: zoom)
    
    //轉換成經緯度
    minX = meters2Lon(minX)
    minY = meters2Lat(minY)
    maxX = meters2Lon(maxX)
    maxY = meters2Lat(maxY)
    
    //轉換目標經緯度爲高德座標系。
    let amapcoord = AMapCoordinateConvert(CLLocationCoordinate2DMake(CLLocationDegrees(minY), CLLocationDegrees(minX)), type)
    minY = amapcoord.latitude
    minX = amapcoord.longitude
    let maxAmapcoord = AMapCoordinateConvert(CLLocationCoordinate2DMake(CLLocationDegrees(maxY), CLLocationDegrees(maxX)), type)
    maxY = maxAmapcoord.latitude
    maxX = maxAmapcoord.longitude
    
    //轉換成墨卡託
    minX = lon2Meters(minX)
    minY = lat2Meters(minY)
    maxX = lon2Meters(maxX)
    maxY = lat2Meters(maxY)
    
    //有博客提到1.1版本和1.3版本有區別，沒有嘗試過，若是你遇到了歡迎補充
    result = "\(minX),\(minY),\(maxX),\(maxY)" //1.1
    //result = "\(minX),\(minY),\(maxX),\(maxY)"//1.3
    
    return result
}

//////添加座標轉換相應的方法
/**
 * X米轉經緯度
 */
func meters2Lon(_ mx: Double) -> Double {
    let lon = mx * DEGREE_PER_METER
    return lon
}

/**
 * Y米轉經緯度
 */
func meters2Lat(_ my: Double) -> Double {
    var lat = my * DEGREE_PER_METER
    lat = 180.0 / .pi * (2 * atan(exp(lat * RAD_PER_DEGREE)) - HALF_PI)
    return lat
}

/**
 * X經緯度轉米
 */
func lon2Meters(_ lon: Double) -> Double {
    let mx = lon * METER_PER_DEGREE
    return mx
}

/**
 * Y經緯度轉米
 */
func lat2Meters(_ lat: Double) -> Double {
    var my = log(tan((90 + lat) * HALF_RAD_PER_DEGREE))/(RAD_PER_DEGREE)
    my = my * METER_PER_DEGREE
    return my
}

2、Mapbox地圖:

建議：作室內地圖的用Mapbox，由於Mapbox縮放級別能夠達到1米的效果。

1.Mapbox的WMS服務和添加柵格圖像是同樣的，甚至不須要咱們作修改,惟一須要注意的是參數：bbox={bbox-epsg-3857}

import UIKit
import Mapbox

class ViewController: UIViewController, MGLMapViewDelegate {
    var mapView: MGLMapView!
    var rasterLayer: MGLRasterStyleLayer?
    
    override func viewDidLoad() {
        super.viewDidLoad()
        
        mapView = MGLMapView(frame: view.bounds)
        mapView.autoresizingMask = [.flexibleWidth, .flexibleHeight]
        
        mapView.setCenter(CLLocationCoordinate2D(latitude: 39.97000000, longitude: 116.3300000), zoomLevel: 20, animated: false)
        
        mapView.delegate = self
        
        view.addSubview(mapView)
        
        // Add a UISlider that will control the raster layer’s opacity.
        addSlider()
    }
    
    func mapView(_ mapView: MGLMapView, didFinishLoading style: MGLStyle) {
        // Add a new raster source and layer.
        let source = MGLRasterTileSource(identifier: "stamen-watercolor", tileURLTemplates: ["http://.../geoserver/xf/wms?service=WMS&version=1.1.0&request=GetMap&layers=zgwz_lzyz_f08_3857&styles=&bbox={bbox-epsg-3857}&width=768&height=704&srs=EPSG:3857&format=image/png"], options: [ .tileSize: 256 ])
        let rasterLayer = MGLRasterStyleLayer(identifier: "stamen-watercolor", source: source)
        
        style.addSource(source)
        style.addLayer(rasterLayer)
        
        self.rasterLayer = rasterLayer
    }
    
    @objc func updateLayerOpacity(_ sender: UISlider) {
        rasterLayer?.rasterOpacity = NSExpression(forConstantValue: sender.value as NSNumber)
    }
    
    func addSlider() {
        let padding: CGFloat = 10
        let slider = UISlider(frame: CGRect(x: padding, y: self.view.frame.size.height - 44 - 30, width: self.view.frame.size.width - padding * 2, height: 44))
        slider.minimumValue = 0
        slider.maximumValue = 1
        slider.value = 1
        slider.isContinuous = false
        slider.addTarget(self, action: #selector(updateLayerOpacity), for: .valueChanged)
        view.insertSubview(slider, aboveSubview: mapView)
        if #available(iOS 11.0, *) {
            let safeArea = view.safeAreaLayoutGuide
            slider.translatesAutoresizingMaskIntoConstraints = false
            let constraints = [
                slider.bottomAnchor.constraint(equalTo: safeArea.bottomAnchor, constant: -mapView.logoView.bounds.height - 10),
                slider.widthAnchor.constraint(equalToConstant: self.view.frame.size.width - padding * 2),
                slider.centerXAnchor.constraint(equalTo: safeArea.centerXAnchor)
            ]
            
            NSLayoutConstraint.activate(constraints)
        } else {
            slider.autoresizingMask = [.flexibleTopMargin, .flexibleLeftMargin, .flexibleRightMargin]
        }
    }
}