topic Re: how to assign a static extent to map.extent in ArcGIS Viewer for Flex Questions

how to assign a static extent to map.extent

wukongsun — Wed, 04 Sep 2013 12:12:34 GMT

Hi Everyone,
    now I'm writing a mouseclickevent , but I don???t know how to give the map.extent a static value.
my code is:map.extent = geo.extent.expand(3);
    I'm very appreciated for your hlep.
    Thank ahead.

Re: how to assign a static extent to map.extent

RobertScheitlin__GISP — Wed, 04 Sep 2013 12:20:52 GMT

wukong sun,

What is the geo object? If it is a MapPoint than it's extent is null.

Re: how to assign a static extent to map.extent

YueWu1 — Wed, 04 Sep 2013 14:43:52 GMT

QiTian,

I think your question is to ask how to create a default extent of the map. Usually, the mouseclick event not control the extent of the map. Like you said, the map extent is usually set with a static value by using Xmin, Ymin, Xmax, Ymax.

I suggest you to read this link might helpful to you to understand the extent in Flex API:
https://developers.arcgis.com/en/flex/guide/using-extent.html

Also, this link provide you the com.esri.ags property, it includes how to use extent syntax
https://developers.arcgis.com/en/flex/api-reference/com/esri/ags/Map.html#extent

Hope this can help you.

Re: how to assign a static extent to map.extent

wukongsun — Fri, 06 Sep 2013 01:02:04 GMT

wukong sun,

What is the geo object? If it is a MapPoint than it's extent is null.

   Yes,you're awesome.the"geo" is my query result.But when it's a MapPoint I can't zoom in to this feature.
   So, could you tell me the way to fix this question.
   Thank you in advance.

Re: how to assign a static extent to map.extent

wukongsun — Fri, 06 Sep 2013 01:07:08 GMT

QiTian,

I think your question is to ask how to create a default extent of the map. Usually, the mouseclick event not control the extent of the map. Like you said, the map extent is usually set with a static value by using Xmin, Ymin, Xmax, Ymax.

I suggest you to read this link might helpful to you to understand the extent in Flex API:
https://developers.arcgis.com/en/flex/guide/using-extent.html

Also, this link provide you the com.esri.ags property, it includes how to use extent syntax
https://developers.arcgis.com/en/flex/api-reference/com/esri/ags/Map.html#extent

Hope this can help you.

Thank you Wu Yue.
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Re: how to assign a static extent to map.extent

RobertScheitlin__GISP — Sat, 11 Dec 2021 19:24:03 GMT

Wukong Sun,

Here is how you handle it (taken your esri code in popuprendereskin):

                var extent:Extent = geometry.extent; // returns null for MapPoint or Multipoint's with only one point
                if (extent)
                {
                    map.zoomTo(geometry);
                }
                else
                {
                    var mapPoint:MapPoint;
                    if (geometry is MapPoint)
                    {
                        mapPoint = geometry as MapPoint;
                    }
                    else if (geometry is Multipoint)
                    {
                        var multipoint:Multipoint = geometry as Multipoint;
                        if (multipoint.points && multipoint.points.length > 0)
                        {
                            mapPoint = multipoint.points[0];
                        }
                    }
                    if (mapPoint)
                    {
                        // make sure the infoWindow always points to the current (selected) feature
                        map.infoWindow.show(mapPoint);
                        // Zoom to 1/16th the size of the current extent.
                        // This is the same as calling map.zoomIn() four times.
                        map.zoom(1 / 16, mapPoint);
                        if (!map.extent.contains(mapPoint))
                        {
                            map.centerAt(mapPoint);
                        }
                    }
                }

Re: how to assign a static extent to map.extent

wukongsun — Sat, 11 Dec 2021 19:24:06 GMT

Wukong Sun,

Here is how you handle it (taken your esri code in popuprendereskin):

                var extent:Extent = geometry.extent; // returns null for MapPoint or Multipoint's with only one point
                if (extent)
                {
                    map.zoomTo(geometry);
                }
                else
                {
                    var mapPoint:MapPoint;
                    if (geometry is MapPoint)
                    {
                        mapPoint = geometry as MapPoint;
                    }
                    else if (geometry is Multipoint)
                    {
                        var multipoint:Multipoint = geometry as Multipoint;
                        if (multipoint.points && multipoint.points.length > 0)
                        {
                            mapPoint = multipoint.points[0];
                        }
                    }
                    if (mapPoint)
                    {
                        // make sure the infoWindow always points to the current (selected) feature
                        map.infoWindow.show(mapPoint);
                        // Zoom to 1/16th the size of the current extent.
                        // This is the same as calling map.zoomIn() four times.
                        map.zoom(1 / 16, mapPoint);
                        if (!map.extent.contains(mapPoint))
                        {
                            map.centerAt(mapPoint);
                        }
                    }
                }

Robert,
      thank you so much for your answer.
      I have test it in my project,and it worked at the beginnig.After I zoom in to the fisrt mappoint I go on want to zoom in to another mappoint,and then the problem appeared.The map extent continue to zoom in till to the limit.
      Now,what I want is that the map extent zoom in to the same scale at everytime I query a mappoint.

      This is my solution:

  map.extent = map.initialExtent;
  var resultlist:Array=new Array();
  for each(var griphic:Graphic in featureSet.features)
  {  
   var geo:Geometry= griphic.geometry;
   var pnt :MapPoint = geo as MapPoint ;
   
   map.centerAt(pnt);
   map.extent = map.extent.expand(0.2);
                          break;
  }

      This code control the map extent base on the initialExtent.
      So when the initialExtent change , we have to change the "expand()" .
      I'm looking for a better solution.
      Your great answer would be appreciated.
Thanks again.

Re: how to assign a static extent to map.extent

RobertScheitlin__GISP — Mon, 09 Sep 2013 11:48:00 GMT

Wukong Sun,

If you want the point always to zoom to a certain scale then just set the maps scale instead of the extent.

map.scale = 2400;

Re: how to assign a static extent to map.extent

wukongsun — Tue, 10 Sep 2013 01:51:22 GMT

Thank you.

Re: how to assign a static extent to map.extent

RobertScheitlin__GISP — Tue, 10 Sep 2013 11:52:55 GMT

wukong sun,

Glad to help now if you can do your part by marking the question as answered. Just complete step 1 in the graphic below: