Unable to cast object of type 'GMap.NET.WindowsPresentation.GMapImage' to type 'GMap.NET.WindowsForms.GMapImage'

[WindingWinter]

Here's the code to illustrate the problem:

   public  class GMapWPFControl: GMap.NET.WindowsPresentation.GMapControl
    {
        public GMapWPFControl()
        {
            MapProvider = GMapProviders.GoogleTerrainMap;
        }
    }


    public class GMapWinFormControl: WindowsFormsHost
    {

        private GMapControl _mapControl;

        public GMapWinFormControl()
        {
            _mapControl = new GMap.NET.WindowsForms.GMapControl();
            _mapControl.MapProvider = GMapProviders.GoogleTerrainMap;
            Child = _mapControl;
        }
    }


<Window
        xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
        xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
        xmlns:d="http://schemas.microsoft.com/expression/blend/2008"
        xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"
        xmlns:local="clr-namespace:tabcontrolgrey"
        x:Class="tabcontrolgrey.MainWindow"
        mc:Ignorable="d"
        Title="MainWindow" Height="350" Width="525">

    <TabControl>
        <TabItem Header="Winform">
            <local:GMapWinFormControl />
        </TabItem>

        <TabItem Header="WPF">
         <local:GMapWPFControl />
        </TabItem>
    </TabControl>

</Window>

The problem occurs when the program is launched, and both Winform and WPF of GmapControl will be loaded, so for Tile.Overlays, it should return the correct GMapImage depending on whether it is WPF or WinForm control, however, at this point, it seems that the wrong GMapImage is loaded into the GMapControl.

An InvalidCastException is thrown because

Unable to cast object of type 'GMap.NET.WindowsPresentation.GMapImage' to type 'GMap.NET.WindowsForms.GMapImage'.

In the above code sample, the WPF version of the GMapImage is loaded into Winform GMapControl, and hence it causes exception.

Any ideas how to workaround, or any fixes for this?

[radioman]

Why do you use winform version in wpf project?

[WindingWinter]

Why do you use winform version in wpf project?

To promote code reuse, I want to reuse some of my legacy winform components in my (new) WPF projects. So it just happens that those legacy winform contains winform greatmaps.net.

This is actually a pretty common scenario, and it's something that Microsoft supports formally via WindowsFormsHost

[radioman]

Ok, but there is wpf version of gmaps https://github.com/radioman/greatmaps/tree/master/GMap.NET.WindowsPresentation

[radioman]

...anyway, if you'd remove the reference of GMap.NET.WindowsPresentation and dll itself, it should work

[WindingWinter]

My use case is that I need to use both the WPF and winform version in my application. For old work I have no choice but to use the winform component, but for new work I want to use Wpf as the main app is WPF . But it seems that WPF and Winform greatmaps.net has a problem coexist. Thinking of fixing it ?

…

On Tue, 3 Dec 2019 at 9:28 PM, radioman ***@***.***> wrote: ...anyway, if you'd remove the reference of GMap.NET.WindowsPresentation and dll itself, it should work — You are receiving this because you authored the thread. Reply to this email directly, view it on GitHub <#153?email_source=notifications&email_token=ADENIZRMC7WI4GWN4MNXKZLQWZNJJA5CNFSM4JSA2KB2YY3PNVWWK3TUL52HS4DFVREXG43VMVBW63LNMVXHJKTDN5WW2ZLOORPWSZGOEFZL2UQ#issuecomment-561167698>, or unsubscribe <https://github.com/notifications/unsubscribe-auth/ADENIZSLDBLEMXKZPFMB2CDQWZNJJANCNFSM4JSA2KBQ> .

[iifuzz]

I am also having this problem.