Ionic2應用程序中的Google地圖

Question

我正在構建一個Ionic2應用程序，其中有一個Google地圖。 我需要：

1. 繪製多邊形
2. 計算它的面積
3. 應該能夠刪除多邊形

基本上，我需要完全按照這裏的同一個解決方案：calculate area of a drawn polygon on google map javascript

到目前爲止，我轉換了打字稿中的整個代碼，它幾乎可以工作。但有一個問題：

• 當我完成第一次繪製多邊形時，區域顯示在UI上。如果在這一點上，我修改我的形狀區域不更新。看到gif圖像。
• 如果我點擊地圖上的任何地方，然後再繪製形狀並對其進行修改，則會針對每個後續修改計算面積。

我在做什麼錯？

我的組件代碼：

import { Component } from '@angular/core'; 
import { NavController, Platform } from 'ionic-angular'; 


@Component({ 
    templateUrl: 'build/pages/start/start.html' 
}) 

export class StartPage { 

    selectedShape: any; 

    constructor(private navController : NavController, private platform : Platform) { 

    this.initializeMap(); 

    } 

    clearSelection = (shape): void => { 

    if(shape) { 
     shape.setEditable(false); 
     shape = null; 
     this.selectedShape=shape 
    } 
    } 

    setSelection = (shape): void => { 

    this.clearSelection(shape); 
    var shape = shape; 
    this.selectedShape=shape; 

    console.log(shape.getPath()) 

    shape.setEditable(true); 
    google.maps.event.addListener(shape.getPath(), 'set_at',()=>{this.calcar(shape)}); 
    google.maps.event.addListener(shape.getPath(), 'insert_at',()=>{this.calcar(shape)}); 
    } 

    calcar= (shape): void => { 

    var shape = shape 

    var area = google.maps.geometry.spherical.computeArea(shape.getPath()); 
    document.getElementById("area").innerHTML = "Area =" + area.toFixed(2); 

    this.selectedShape=shape 
    } 

    deleteSelectedShape =(): void => { 

    if (this.selectedShape) { 
     this.selectedShape.setMap(null); 
    } 
    } 

    initializeMap =(): void => { 

    var newShape 
    var map 
    var drawingManager 

    this.platform.ready().then(() => { 
     var minZoomLevel = 15; 

     map = new google.maps.Map(document.getElementById('map_canvas'), { 
     zoom: minZoomLevel, 
     center: new google.maps.LatLng(52.5200, 13.4050), 
     mapTypeId: google.maps.MapTypeId.ROADMAP, 
     disableDefaultUI: true, 
     zoomControl: true  
     }); 

     var polyOptions = { 
     strokeWeight: 0, 
     fillOpacity: 0.45, 
     editable: true 
     }; 

     drawingManager = new google.maps.drawing.DrawingManager({ 
     drawingControl: true, 
     drawingControlOptions: { 
      drawingModes: [ 
      google.maps.drawing.OverlayType.POLYGON, 
      ] 
     }, 
     polygonOptions: polyOptions, 
     map: map 
     }); 

     google.maps.event.addListener(drawingManager, 'overlaycomplete', (e) => { 

     this.selectedShape=e.overlay 

     if (e.type != google.maps.drawing.OverlayType.MARKER) { 
     // Switch back to non-drawing mode after drawing a shape. 
     drawingManager.setDrawingMode(null); 

     // Add an event listener that selects the newly-drawn shape when the user 
     // mouses down on it. 
     newShape = e.overlay; 
     newShape.type = e.type; 

     google.maps.event.addListener(newShape, 'click',()=> { 

     this.setSelection(newShape); 


     }); 

     var area = google.maps.geometry.spherical.computeArea(newShape.getPath()); 
     document.getElementById("area").innerHTML = "Area =" + area.toFixed(2); 

    () => {this.setSelection(newShape);} 
    } 
    }); 

     google.maps.event.addListener(map, 'click', ()=>{this.clearSelection(newShape);}); 
     google.maps.event.addDomListener(document.getElementById('delete-button'), 'click', ()=>{this.deleteSelectedShape();}); 

    }); 

    } 

} 

Answer 1

你的錯誤就設在這裏：

var area = google.maps.geometry.spherical.computeArea(newShape.getPath()); 
    document.getElementById("area").innerHTML = "Area =" + area.toFixed(2); 

() => {this.setSelection(newShape);} <== this line 
} 

你不叫setSelection功能。這是一樣的：

function() { 
    this.setSelection(newShape); 
}; 

您需要使用以下方法：

this.setSelection(newShape); 

又見working plunker