var registration = NavigationManager.RegisterLocationChangingHandler(async cxt =>
{
    if (cxt.TargetLocation.EndsWith("counter"))
    {
        cxt.PreventNavigation();
    }
});

<NavigationLock OnBeforeInternalNavigation="ConfirmNavigation" ConfirmExternalNavigation />

<EditForm EditContext="editContext" OnValidSubmit="Submit">
    ...
</EditForm>
<NavigationLock OnBeforeInternalNavigation="ConfirmNavigation" ConfirmExternalNavigation />

    @code {
        private readonly EditContext editContext;
        ...

        // Called only for internal navigations.
        // External navigations will trigger a browser specific prompt.
        async Task ConfirmNavigation(LocationChangingContext context)
        {
            if (editContext.IsModified())
            {
                var isConfirmed = await JS.InvokeAsync<bool>("window.confirm", 
                   "Are you sure you want to leave this page?");
                
                if (!isConfirmed)
                {
                    context.PreventNavigation();
                }
            }
        }
    }

Moving the standards work into the open, under the .NET Foundation, makes it easier for standardization work. Everything from language innovation and feature design through implementation and on to standardization now takes place in the open. It will be easier to ask questions among the language design team, the compiler implementers, and the standards committee. Even better, those conversations will be public. 

Database management done right. Connection explorer, query runner, intellisense, bookmarks, query history. Feel like a database hero! 

If you are used to manipulate HTML forms, you probably know that each checkbox is a separate variable (or maybe an ngModel with AngularJS).  Demo

Sometimes, it could be usefull to manipulate all these checkboxes as a unique array.

angular.checkboxes module lets you turn your list of checkboxes into a unique destination array, providing :

• two-way binding: manipulate the destination array will check/uncheck the checkboxes AND check/uncheck the checkboxes will modify the destination array.
• no isolated scope for each checkbox: the directive does not create new child scope.
• a mtCheckboxController: internal controller can be injected to other directives. 

In this post, I will describe how to port a desktop application from .NET Framework to .NET Core. I picked a WinForms application as an example. Steps for WPF application are similar and I’ll describe what needs to be done different for WPF as we go. I will also show how you can keep using the WinForms designer in Visual Studio even though it is under development and is not yet available for .NET Core projects. 

Security Advisory Notice for 16.6.2

CVE-2020-1108 / CVE-2020-1108.NET Core Denial of Service Vulnerability

To comprehensively address CVE-2020-1108, Microsoft has released updates for .NET Core 2.1 and .NET Core 3.1. Customers who use any of these versions of .NET Core should install the latest version of .NET Core. See the Release Notes for the latest version numbers and instructions for updating .NET Core.

CVE-2020-1202 / CVE-2020-1203 Diagnostics Hub Standard Collector Service Elevation of Privilege Vulnerability

An elevation of privilege vulnerability exists when the Diagnostics Hub Standard Collector or the Visual Studio Standard Collector fails to properly handle objects in memory.

CVE-2020-1293 / CVE-2020-1278 / CVE-2020-1257 Diagnostics Hub Standard Collector Service Elevation of Privilege Vulnerability

An elevation of privilege vulnerability exists when the Diagnostics Hub Standard Collector Service improperly handles file operations

Top Issues Fixed in Visual Studio 2019 version 16.6.2

• Visual Studio 2019 16.60 hang at run or build when modified not saved in C++/CLI project
• An unhandled exception of type 'System.NullReferenceException' occurred in Microsoft.VisualStudio.DesignTools.WpfTap.dll
• Recurring null reference when reopening documents
• "Create new project" dialog search does not find templates for third-party language providers
• IntelliSense shows that "tilde-slash" (~/) points to ASP .NET Core 3.1 project root instread of wwwroot subfolder after upgrading Visual Studio Enterprise 16.5.6->16.6.0
• Fixed a compiler error (error C2475: redefinition; 'constexpr' specifier mismatch) affecting std::atomic when compiled as C++/CX in C++17 mode.
• URL completion values and format was fixed in Razor views. App-relative URL format is now used again and the values in the URL completion list show files and folders rooted under app root, i.e. wwwroot.
• Fixed a crash when using snippets.
• Restore item templates that could be hidden by extensions.