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How to zoom in or zoom out in a map without using Javascript? RRS feed

  • Question

  • User1616284541 posted

    Hi,

    I need to upgrade an Asp based GIS system to Asp.net and I found it had been used many javascript code to mapping issues, such as zooming in and out. Does anybody know to realize these features on server side? I mean I just use C# components to do it like java applet. Thanks a lot in advance.

    Thursday, March 31, 2005 11:22 AM

All replies

  • User-1385434563 posted
    I assume you are using Javascript to determine where the user wants to zoom to. If you want it to be totally free of client script and be "server only" you will be limited to a mouse click only i.e. a predetermined zoom and at point. This is the way I do it on PDA's. In the main most GIS systems have some Javascript at least.
    Friday, April 1, 2005 4:07 AM
  • User-597377768 posted

    I'm now studying about GDI+. I just want to write what I think. I hope this is helpful.

    Mainpage.aspx <---- Mapshow.aspx (manipulates image)

    Mainpage.aspx obtains appropriate map image path, the point of the center of the image,the point that the user clicked(optional),  zoom level, any data the page may need....

    Mainpage.aspx requests the image to Mapshow.aspx. And, Mapshow.aspx loads the raw image and resize the image by the zoom level, and crop it by a proper size. Finally, Mapshow.aspx draws strings and symbols on the modified image at the correct place. and save it through its response stream to send the image to Mainpage.aspx

    Mainpage.aspx show the image. So, Mapshow.aspx is the core program which retrieves data from DB and calculates the coordinations according to the zoom level, and modifies the map images appropriately.

    I think the point the user clicks can be detected by javascript, calculating the point of click and the left-top point(location) of the map image.

     

    Saturday, April 9, 2005 12:36 AM
  • User-958060159 posted

    Try SharpMap it is a free .NET Mapping Engine, you can use it to build interactive maps using ASP .NET 2 . There is also a tutorial on how to use it check it out here:

    http://www.codeproject.com/aspnet/sharpmap1.asp

    SharpMap

    http://sharpmap.iter.dk/

    Good luck

     

    Sunday, March 26, 2006 12:16 PM