Zoom to a Window in Editor using CommandASync

csharp

Zoom to a Window in Editor using CommandASync                         By Madhukar Moogala
In this post, I will illustrate a sample based on AutoCAD 2015 API Editor.CommandAsync.
Problem: Can I zoom to particular window in an Editor as long as I press esc or cancel to quit?
Answer: Yes, with help of CommandAsync, you can achieve this task.

#region "send Zoom command by callback function"

private static bool ZoomExit = false;

//declare the callback delegation

delegate void Del();

private static Del _actionCompletedDelegate;

// Exit function，check if Zoom command is esc\cancelled

static void

MdiActiveDocument_CommandCancelled(object sender,CommandEventArgs e)

{

    ZoomExit = true;

}

[CommandMethod("TestZoom")]

public static void TestZoom()

{

   var ed = Application.DocumentManager.MdiActiveDocument.Editor;

   var doc = Application.DocumentManager.MdiActiveDocument;

   //esc event

   doc.CommandCancelled += MdiActiveDocument_CommandCancelled;

   // start Zoom command

   Editor.CommandResult cmdResult1 =

   ed.CommandAsync(new object[]{

   "_.ZOOM", Editor.PauseToken, Editor.PauseToken});

   // delegate callback function, wait for interaction ends

   _actionCompletedDelegate = new Del(CreateZoomAsyncCallback);

   cmdResult1.OnCompleted(new Action(_actionCompletedDelegate));

   ZoomExit = false;

}

// callback function

public static void CreateZoomAsyncCallback()

{

    var ed = Application.DocumentManager.MdiActiveDocument.Editor;

    //if Zoom command is running

    if (!ZoomExit)

    {

        // AutoCAD hands over to the callback function

        Editor.CommandResult cmdResult1 =

        ed.CommandAsync(new object[]{

        "_.ZOOM", Editor.PauseToken, Editor.PauseToken});

        // delegate callback function, wait for interaction ends

        _actionCompletedDelegate = new Del(CreateZoomAsyncCallback);

       cmdResult1.OnCompleted(new Action(_actionCompletedDelegate));

    }

    else

    {

        ed.WriteMessage("Zoom Exit");

        return;

    }

}