首页 \ 问答 \ 坐标数组(Array of Coordinates)

坐标数组(Array of Coordinates)

 我在javascript中有一个坐标数组，声明为path1 = new Array(); 没有大小。 我将只从我的Android应用程序推送坐标发送并使用此数组作为我的折线的路径。  
 现在我的问题是，数组中有多少元素有限制吗？  
 我尝试跟踪我的gps，前几个坐标工作正常。 我可以看到我的折线。 但突然间折线会消失。  
 任何帮助将不胜感激。 对不起，我的英语不好。  
enter code herefunction path(sender,latitude,longitude,speed,id,path,color,plength){
var latlng = new google.maps.LatLng(latitude,longitude);
var polyPath = polyArray(path);
createPoly(polyPath,color);
createMarker(latlng,sender,speed,plength);
}
function polyArray(path){
var array = path.split(',');
var path1 =new Array();
for(var i=0;i<=array.length;i=i+2){
var coordinates = new google.maps.LatLng(array[i],array[i+1]);
path1.push(coordinates);
}
return path1;
} 
function createPoly(path,color){
var polyOptions = {
path:path,
strokeColor: color,
strokeOpacity: 1.0,
strokeWeight: 1
};
poly = new google.maps.Polyline(polyOptions);
poly.setMap(map);
}
function createMarker(latlng,sender,speed,plength){
var marker = new google.maps.Marker({
position: latlng,
map: map
});
var infowindow = new google.maps.InfoWindow({content:sender + "\n" + speed + "m/s"});
infowindow.open(map, marker);
markers.push(marker);
for(var i=0;i<markers.length-plength;i++)
markers[i].setMap(null);
}
google.maps.event.addDomListener(window, 'load', initialize); 

I have an array of coordinates in javascript declared as path1 = new Array(); with no size. I will just push the coordinates send from my android application and use this array as a path for my polyline. 
Now my question is, is there a limit on how many elements in an array? 
I try to track my gps and the first few coordinates works fine. I can see my polyline. But suddenly the polyline will disappear. 
Any help will be appreciated. Sorry for my bad english. 
enter code herefunction path(sender,latitude,longitude,speed,id,path,color,plength){
var latlng = new google.maps.LatLng(latitude,longitude);
var polyPath = polyArray(path);
createPoly(polyPath,color);
createMarker(latlng,sender,speed,plength);
}
function polyArray(path){
var array = path.split(',');
var path1 =new Array();
for(var i=0;i<=array.length;i=i+2){
var coordinates = new google.maps.LatLng(array[i],array[i+1]);
path1.push(coordinates);
}
return path1;
} 
function createPoly(path,color){
var polyOptions = {
path:path,
strokeColor: color,
strokeOpacity: 1.0,
strokeWeight: 1
};
poly = new google.maps.Polyline(polyOptions);
poly.setMap(map);
}
function createMarker(latlng,sender,speed,plength){
var marker = new google.maps.Marker({
position: latlng,
map: map
});
var infowindow = new google.maps.InfoWindow({content:sender + "\n" + speed + "m/s"});
infowindow.open(map, marker);
markers.push(marker);
for(var i=0;i<markers.length-plength;i++)
markers[i].setMap(null);
}
google.maps.event.addDomListener(window, 'load', initialize); 

原文：https://stackoverflow.com/questions/21108227

更新时间：2023-08-13 20:08

最满意答案

 看下面的例子：  
enum E1 { e1 };
enum E2 { e2 };

public  class Test <E extends Enum> {
  List<E> list = new ArrayList<>();

  void add(E e) { list.add(e); } 
  void dump() { System.out.println(list); }

  public static void main(String[] args) throws Exception {
    Test<Enum> test = new Test<>();
    test.add(E1.e1);
    test.add(E2.e2);
    test.dump();    
  }
}
 
 你可以声明一个列表来接受“任何枚举”; 因为任何枚举类都必须从Enum派生，您可以使用该特定类来实例化一个Test，以允许添加来自枚举类的枚举常量。  
 当然，这更像是一个“代码难题”; 因为我认为这样的设计非常谨慎; 不是我在“真实世界生产”代码中会做的事情。 

See the following example: 
enum E1 { e1 };
enum E2 { e2 };

public  class Test <E extends Enum> {
  List<E> list = new ArrayList<>();

  void add(E e) { list.add(e); } 
  void dump() { System.out.println(list); }

  public static void main(String[] args) throws Exception {
    Test<Enum> test = new Test<>();
    test.add(E1.e1);
    test.add(E2.e2);
    test.dump();    
  }
}
 
You can declare a list to accept "any enum"; and as any enum class must be derived from Enum, you can then use that specific class to instantiate a Test that allows to add enum constants coming from enum classes. 
Of course, this is more of a "code puzzle"; as I would regard such a design with a lot of caution; not something that I would do in "real world production" code.

坐标数组(Array of Coordinates)

最满意答案

相关问答

Enums需要多少内存？(How much memory do Enums take?)[2022-12-27]

创建枚举列表？(Creating List of Enums?)[2022-08-05]

Enums周围的Pythonic方式[关闭](Pythonic way around Enums [closed])[2022-04-14]

保持排列列表中的枚举？(Keeping enums sorted in an arraylist?)[2022-05-21]

Arraylist，if else语句(Arraylist, with if else statements)[2024-01-06]

让arraylist等于另一个arraylist java(make arraylist equal another arraylist java)[2023-09-05]

你如何制作不同枚举的数组列表？(how do you make an arraylist of different enums?)[2022-02-01]

我应该使用Enums作为鉴别器吗？(Should I ever use Enums as discriminators?)[2022-09-25]

roslyn能生成枚举吗？(Can roslyn generate enums?)[2023-04-06]

如何制作可扩展的ArrayList？(How to make extendible ArrayList?)[2023-12-01]

相关文章

最新问答