Personal understanding of LODs keyword functionality in the ArcGIS API

About LODs's understanding

Since the individual is two times for ArcGIS to develop, for the professional geography knowledge of ArcGIS is not very understanding, in two times encountered in the development of some English terminology difficult to understand the meaning of the representative, such as the LODs keyword is to translate tiles good or tile good? As I understand it doesn't matter anymore, I use the ArcGIS API for Flex development code as a demonstration to see exactly what LODs is.

The following flex. Mxml Program Code

<?xml version= "1.0" encoding= "Utf-8"?> <s:application xmlns:fx= "http://ns.adobe.com/mxml/2009" xmlns:s= "Library://ns.adobe.com/flex/spark" Xmlns:esri= "http://www.esri.com/2008/ags" Backgroundcolor= "0xEEEEEE" Pagetitle= "Specifying specific tile levels ( specify tile level )"> <esri:Map> <esri:lods> <esri:lod resolution= "0.0439453125" scale= "18468599.9106772"/> <esri:lod resolution= "0.02197265625" scale= "9234299.95533859"/> <esri:lod resolution= "0.010986328125" scale= "4617149.97766929"/> <esri:lod resolution= "0.0054931640625" scale= "2308574.98883465"/> <esri:lod resolution= "0.00274658203125" scale= "1154287.49441732"/> </esri:lods> <esri:extent> <esri:extent xmin= "-124.629" ymin= "18.826" xmax= "-68.027" ymax= "56.311 "> <esri:spatialreference wkid= "4269"/> </esri:Extent> </esri:extent> <esri:arcgisdynamicmapservicelayer url= "http://sampleserver1.arcgisonline.com/ArcGIS/rest/ Services/demographics/esri_census_usa/mapserver"/> </esri:Map> </s:Application>

The above code can also refer to the official API example to see the effect: https://developers.arcgis.com/flex/sample-code/only-use-some-scales-lods.htm

The code demonstrates effects such as,

At this point we observe that the level on the Zoom slider bar in the upper left corner is exactly 5 levels, and our <esri:lod in the Flex program ... The number of /> is the same, that is, we can customize the zoom level of the slider, the resolution property in the parameter can set the resolution of the current level and the Scale property setting bar

If we do not set <esri:lod ... What does the /> effect look like?

<?xml version= "1.0" encoding= "Utf-8"?> <s:application xmlns:fx= "http://ns.adobe.com/mxml/2009" xmlns:s= "Library://ns.adobe.com/flex/spark" Xmlns:esri= "http://www.esri.com/2008/ags" Backgroundcolor= "0xEEEEEE" Pagetitle= "Specifying specific tile levels ( specify tile level )"> <esri:Map> <esri:extent> <esri:extent xmin= "-124.629" ymin= "18.826" xmax= "-68.027" ymax= "56.311 "> <esri:spatialreference wkid= "4269"/> </esri:Extent> </esri:extent> <esri:arcgisdynamicmapservicelayer url= "http://sampleserver1.arcgisonline.com/ArcGIS/rest/ Services/demographics/esri_census_usa/mapserver"/> </esri:Map> </s:Application>

We observed that there is no level in scaling, we can click "+", "–" Infinity and minimum

We opened the URL address on the <esri:ArcGISDynamicMapServiceLayer/> tab and found that the original returned content does not contain information about the level of the map. Http://sampleserver1.arcgisonline.com/ArcGIS/rest/services/Demographics/ESRI_Census_USA/MapServer

So I understand that to not use content that contains level to set LOD content, there is also a discovery that once we are working with the following code

<esri:arcgistiledmapservicelayer /> We can set LOD or not set LOD content, if not set will default to use the level of Arcgistiledmapservicelayer , because it is the information containing levels

<esri:map extent= "{initialextent}"> <esri:lods> <esri:lod level= "0" resolution= "156543.033928" scale= "591657527.591555" /> <esri:lod level= "1" resolution= "78271.5169639999" scale= "295828763.795777" /> <esri:lod level= "2" resolution= "39135.7584820001" scale= "147914381.897889" /> <esri:lod level= "3" resolution= "19567.8792409999" scale= "73957190.948944" /> <esri:lod level= "4" resolution= "9783.93962049996" scale= "36978595.474472" /> <esri:lod level= "5" resolution= "4891.96981024998" scale= "18489297.737236" /> <esri:lod level= "6" resolution= "2445.98490512499" scale= "9244648.868618" /> <esri:lod level= "7" resolution= "1222.99245256249" scale= "4622324.434309" /> <esri:lod level= "8" resolution= "611.49622628138" scale= "2311162.217155" /> </esri:lods> <esri:arcgisdynamicmapservicelayer url= "http://sampleserver1.arcgisonline.com/ArcGIS/rest/ Services/demographics/esri_population_world/mapserver"alpha="0.5"/> <esri:arcgistiledmapservicelayer url= "http://server.arcgisonline.com/ArcGIS/rest/ Services/reference/world_reference_overlay/mapserver"/> </esri:Map>

There is the wrong place also hope to point out thank you!

Personal understanding of LODs keyword functionality in the ArcGIS API