Dirty LOG in MAC

Question

Dirty LOG in MAC

Dani_S 4,361

Mar 23, 2025, 10:06 AM

Hi,

2025-03-23 12:01:35,747 [1] ERROR GssdDesktopClient.Maui.Helpers.UtillHelper - LoginCommand

System.NullReferenceException: Object reference not set to an instance of an object.

at GssdDesktopClient.Maui.Pages.LoginPage.OnHandlerChanged() in /Users/sasasoftware/Documents/GssdDesktopClient/GssdDesktopClient.Maui/Pages/LoginPage.xaml.cs:line 21

at Microsoft.Maui.Controls.Element.OnHandlerChangedCore()

at Microsoft.Maui.Controls.VisualElement.OnHandlerChangedCore()

at Microsoft.Maui.Controls.Element.SetHandler(IElementHandler newHandler)

at Microsoft.Maui.Controls.Element.set_Handler(IElementHandler value)

at Microsoft.Maui.Controls.VisualElement.Microsoft.Maui.IElement.set_Handler(IElementHandler value)

at Microsoft.Maui.Handlers.ElementHandler.DisconnectHandler(Object platformView)

at Microsoft.Maui.Handlers.ElementHandler.Microsoft.Maui.IElementHandler.DisconnectHandler()

at Microsoft.Maui.ViewExtensions.DisconnectHandlers(IView view)

at Microsoft.Maui.Controls.Window.OnPageChanged(Page oldPage, Page newPage)

at Microsoft.Maui.Controls.Window.<>c.<.cctor>b__216_0(BindableObject b, Object o, Object n)

at Microsoft.Maui.Controls.BindableObject.OnBindablePropertySet(BindableProperty property, Object original, Object value, Boolean didChange, Boolean willFirePropertyChanged)

at Microsoft.Maui.Controls.Element.OnBindablePropertySet(BindableProperty property, Object original, Object value, Boolean changed, Boolean willFirePropertyChanged)

at Microsoft.Maui.Controls.BindableObject.SetValueActual(BindableProperty property, BindablePropertyContext context, Object value, Boolean currentlyApplying, SetValueFlags attributes, SetterSpecificity specificity, Boolean silent)

at Microsoft.Maui.Controls.BindableObject.SetValueCore(BindableProperty property, Object value, SetValueFlags attributes, SetValuePrivateFlags privateAttributes, SetterSpecificity specificity)

at Microsoft.Maui.Controls.BindableObject.SetValue(BindableProperty property, Object value)

at Microsoft.Maui.Controls.Window.set_Page(Page value)

at Microsoft.Maui.Controls.Application.set_MainPage(Page value)

at GssdDesktopClient.Maui.ViewModels.LoginViewModel.<InitCommands>b__94_0() in /Users/sasasoftware/Documents/GssdDesktopClient/GssdDesktopClient.Maui/ViewModels/LoginViewModel.cs:line 520

Update

//Override the method of the page

protected override void OnHandlerChanged()

{

base.OnHandlerChanged();

// Window.FlowDirection = FlowDirection.LeftToRight;

}

when I comment this row the log become clean why?

Dani_S 4,361 Reputation points

Mar 23, 2025, 10:11 AM

//Override the method of the page

protected override void OnHandlerChanged()

{

base.OnHandlerChanged();

// Window.FlowDirection = FlowDirection.LeftToRight;

}

when I comment this row the log become clean why?
Wenyan Zhang (Shanghai Wicresoft Co,.Ltd.) 36,331 Reputation points Microsoft External Staff

Mar 24, 2025, 7:31 AM

Using .NET8 or .NET9? This error means the object or reference is null. You could check whether the Windows is null or not.

Also, could you share the code snippets at /Users/sasasoftware/Documents/GssdDesktopClient/GssdDesktopClient.Maui/ViewModels/LoginViewModel.cs:line 520?
Dani_S 4,361 Reputation points

Mar 24, 2025, 7:32 AM

Using net 9
Dani_S 4,361 Reputation points

Mar 24, 2025, 7:37 AM
line 520

var desktopClientConfigurationResults = await automationApiClient.GetDesktopClientConfiguration($"{LoginConfigurations.GetInstance().Portal}/api/desktop/getDesktopConfiguartion", LoginConfigurations.GetInstance().SessionToken);

if (string.IsNullOrEmpty(desktopClientConfigurationResults))

{

IsOpenPopup = true; ErrorMessage = "Get client configuration from DOME failed , please contact your system administrator for further details."; _logger.Error(ErrorMessage); return;

}
Dani_S 4,361 Reputation points

Mar 24, 2025, 7:49 AM

I tested is not null, please see:

https://app.screencast.com/AZQhPqwz9tDpq
Wenyan Zhang (Shanghai Wicresoft Co,.Ltd.) 36,331 Reputation points Microsoft External Staff

Mar 25, 2025, 5:58 AM

Is the code in the LoginCommand method? Are there any other null objects here?