On a window with MapPoint 2004 I found my program hanging and needing to be reboored.

In the automaticaly generated code by Visual Studio, in the Dispose() function, it hung on base.Dispose(). I also noticed the map had previously displayed the entire map of North America, wherease normally it displays a much smaller area, a few minles accross.

What kind of error could have caused this to crash like that? The program simply hung at base.Dispose().

Hope to hear from you.

Thanks,
BobFromBoston

Could I have a memory leak? I do nothing to dispose of these objects.

I'm a C++ developer turned C# developer, and thought these things were handled for me. But now I wonder if I need to explictly dispose of each pushpin when I dispose of the window.

Is that true?

BobFromBoston.

Here is the Dispose function generated by Visual Studio 2005.

Is this enough to clean up the MapPoint resources?


BobFromBoston

protected override void Dispose( bool disposing )
{
if( disposing )
{
if(components != null)
{
components.Dispose();
}
}
base.Dispose( disposing );
}

Hi,

I don't know why it hangs but possible there is a lot to clean up and it is done at program termination. But cleaning up takes memory, so possible that's the reason. You need to dispose everything your create yourself. Only the things that are dropped on a form or so you don't dispose. If you don't then it will look as if you have memory leaks and your program will terminate very slow.

About your question of pushpins, I don't know. but I do delete them always. It is a good habitude to destroy what you don't need anymore.

This is an example of a class using mappoint activex control. it also demonstrate the Dispose method (C#):

Code:

public Foo(Control Owner)
{
    owner = Owner;
    mp = new AxMapPoint.AxMappointControl();
    owner.Controls.Add(mp);
}

~Foo()
{
    Dispose(false);
}

public void Dispose()
{
    Dispose(true);
    GC.SuppressFinalize(this);
}

protected virtual void Dispose(bool disposeManagedResources)
{
    if (!disposed) {
	if (disposeManagedResources) {
	    map.Saved = true;
	    owner.Controls.Remove(mp);
	    mp.Dispose();
	    mp = null;
	}
	disposed = true;
    }
}

Yes Disposing always seems more complicated than it should be. Wilfried's implementation looks about right. A good C# book should also cover how to implement IDisposable.
You have to make sure you don't dispose thinks that have been deleted or already disposed / etc.

Richard

Thanks for the help.

Bob

I have functions inside my program which access a MapPoint map object that is always present in my program, sine the same window is always open. Is the method (shown below) of clearing the route acceptable for memory management? I clear the route before I start putting the two new waypoints into it. Is this the best way to clear this memory used? Is this a memory leak?

I have some sort of memory leak with MapPoint that I am trying to find. Is there a need for me to call the Delete() method associatd with each waypoint as well? Or is calling mpRoute.Clear(); sufficient?

Thanks,
Bob


public static string GetMilesAndMinutes( Handles handles, Coordinates pointA, Coordinates pointB )
{
string returnStr = null;
MapPoint.Route mpRoute = null;
MapPoint.Map mpMap = handles.MapPointMap;
mpRoute = mpMap.ActiveRoute;

mpRoute.Clear();

MapPoint.Location locA = mpMap.GetLocation( pointA.Latitude, pointA.Longitude, 100 );
if ( locA == null )
{
return null;
}
mpRoute.Waypoints.Add( locA, "locA" );

MapPoint.Location locB = mpMap.GetLocation( pointB.Latitude, pointB.Longitude, 100 );
if ( locB == null )
{
return null;
}

mpRoute.Waypoints.Add( locB, "locB" );
mpRoute.Calculate();
double thisMinutes = Math.Round( mpRoute.DrivingTime * 24 * 60, 1);
double thisMiles = Math.Round( mpRoute.Distance, 2);
double comparisonMiles = mpMap.Distance( locA, locB );
returnStr = thisMiles.ToString() + "," + thisMinutes.ToString();
return returnStr;
}

Hi,

As far as I know is clearing the route sufficient.