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I've got a Web Application with C# code that creates a list of objects with their long and lat. I want to then create marker points on Google Maps for them using Javascript. I've currently got this code:

  var marker;
  for (var i = 0; i < ('<%= Buses.Count %>' - 1); i++) {
       marker = new google.maps.Marker({
       position: new google.maps.LatLng('<%= Buses['i'].latitude %>', '<%= Buses['i'].longitude  %>'),
        map: map
       });
  }

Which does not work, I believe the error is with where I reference "i" to say which object in the list to use.

If I manually set a marker point without a for loop and change ['i'] to [0] it will place a marker fine. However, due to the number of items changing and reaching up to 100 I require using a for loop. I have tried removing the '' around i and this generates an error saying

"i does not exist in the current context."

I have seen these posts: Add two marker points in google maps

Google Maps JS API v3 - Simple Multiple Marker Example

Google Maps JS API v3 - Simple Multiple Marker Example

However, all of these are using locations inside of the JavaScript. My objects are contained within the C# code as a custom object defined as:

public static List<Bus> Buses = new List<Bus>();

This is my C# Code in full: https://pastebin.com/2M1hWjnM

samtrod
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1 Answers1

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You're mixing a javascript for with data in code-behind/C#. It not works. First, you've to put the marks data on a javascript array. Then make your for without webforms tags <%%>

put something like this on your page code behind (C#)

public static string getBusesJson()
    {
        var buses = new List<Bus>();

        buses.Add(new Bus() {latitude = 10, longitude = 20 });
        buses.Add(new Bus() { latitude = 15, longitude = 30 });
        buses.Add(new Bus() { latitude = 5, longitude = 40 });

        return JsonConvert.SerializeObject(buses);

    }

put this on your aspx header:

<script type="text/javascript">

    var points = <%= WebApplication3.WebForm1.getBusesJson()%>;

    for (var i = 0; i < points.length; i++) {
        //pass points[i].latitude and points[i].longitude to google maps
    }

</script>
Rafael Oliveira
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