.NET Framework is a software framework developed by Microsoft that runs primarily on Microsoft Windows.
.NET Framework includes a large class library named as Framework Class Library and provides language interoperability across several programming languages.
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.NET is a không tính phí, cross-platform, open source developer platform for building many different types of applications. .NET Framework is the original implementation of .NET. It supports running websites, services, desktop apps, và more on Windows.
With .NET, you can use multiple languages, editors, and libraries lớn build for web, điện thoại, desktop, gaming, & IoT.
You can write .NET apps in C#, F#, or Visual Basic.C# is a simple, modern, object-oriented, và type-safe programming language.F# is a cross-platsize, open-source, functional programming language for .NET. It also includes object-oriented & imperative sầu programming.Visual Basic is an approachable language with a simple syntax for building type-safe, object-oriented apps.
The runtime includes everything you need khổng lồ run existing apps/programs built with .NET Framework.
The developer paông chồng is used by software developers to lớn create applications that run on .NET Framework, typically using Visual Studio.
Today, we are releasing the .NET April 2021 Updates. These updates contains reliability và other non-security improvements. See the individual release notes for details on updated packages.
.NET SDK 5.0.202 resolves an issue where NuGet restore fails on Linux due lớn expired NuGet certificates & unfortunate interactions with changes made to root certificates stores on Linux, carried by ca-certificates and nss packages.
ImprovementsRuntime : 5.0.8ASP.NET Core : 5.0.8EntityFramework Vi xử lý Core : 5.0.8Winforms: 5.0.8.NET 5 NuGet Restore Failures on Linux distributions using NSS or ca-certificates
.NET SDK 5.0.202 resolves an issue where NuGet restore fails on Linux due to lớn expired NuGet certificates & unfortunate interactions with changes made to lớn root certificates stores on Linux, carried by ca-certificates and nss packages.
Supported Windows Versions
Windows Client versions: Windows 10 version 1903, Windows 10 version 1809, Windows 10 version 1803, Windows 10 version 1709, Windows 10 version 1703, Windows 10 version 1607, Windows 8.1, Windows 7 SP1
Windows Server versions: Windows Server 2019, Windows Server version 1803, Windows Server năm nhâm thìn, Windows Server 2012, Windows Server 2012 R2, Windows Server 2008 R2 SP1
New Features in .NET Framework
Runtime – JIT improvementsThe JIT in .NET 4.8 is based on .NET bộ vi xử lý Core 2.1. All bug fixes và many code generation-based performance optimizations from .NET Core 2.1 are now available in the .NET Framework.
Runtime – NGEN improvementsNGEN images in the .NET Framework no longer contain writable và executable sections. This reduces the surface area available lớn attacks that attempt to lớn exexinh tươi arbitrary code by modifying memory that will be executed.While there will still be writable và executable data in memory at runtime, this change removes those mapped from NGEN images, allowing them khổng lồ run in restricted environments that don’t permit executable/writable sections in images.
Runtime – Antimalware Scanning for All AssembliesIn previous versions of .NET Framework, Windows Defender or third-tiệc nhỏ antimalware software would automatically scan all assemblies loaded from disk for malware. However, assemblies loaded from elsewhere, such as by using Assembly.Load(byte<>), would not be scanned & could potentially carry viruses undetected..NET Framework 4.8 on Windows 10 triggers scans for those assemblies by Windows Defender & many other antimalware solutions that implement the Antimalware Scan Interface. We expect that this will make it harder for malware to lớn disguise itself in .NET programs.
BCL – Updated ZLibStarting with .NET Framework 4.5 we used the native sầu version of ZLib (a native external compression library used for data compression) from https://zlib.net in clrcompression.dll in order to lớn provide an implementation for the deflate algorithm. In .NET Framework 4.8 we updated clrcompression.dll to use version 1.2.11 which includes several key improvements & fixes.
BCL – Reducing FIPS Impact on Cryptography
.NET Framework 2.0+ have cryptographic provider classes such as SHA256Managed, which throw a CryptographicException when the system cryptographic libraries are configured in “FIPS mode”. These exceptions are thrown because the managed versions have not undergone FIPS (Federal Information Processing Standards) 140-2 certification (JIT and NGEN image generation would both invalidate the certificate), unlượt thích the system cryptographic libraries. Few developers have sầu their development machines in “FIPS mode”, which results in these exceptions being raised in production (or on customer systems). The “FIPS mode” setting was also used by .NET Framework to lớn block cryptographic algorithms which were not considered an approved algorithm by the FIPS rules.
For applications built for .NET Framework 4.8, these exceptions will no longer be thrown (by default). Instead, the SHA256Managed class (& the other managed cryptography classes) will redirect the cryptographic operations khổng lồ a system cryptography library. This policy change effectively removes a potentially confusing difference between developer environments & the production environments in which the code runs và makes native sầu components & managed components operate under the same cryptographic policy.
Applications targeting .NET Framework 4.8 will automatically switch to lớn the newer, relaxed policy và will no longer see exceptions being thrown from MD5Cng, MD5CryptoServiceProvider, RC2CryptoServiceProvider, RIPEMD160Managed, and RijndaelManaged when in “FIPS mode”. Applications which depend on the exceptions from previous versions can return to the previous behavior by setting the AppContext switch “Switch.System.Security.Cryptography.UseLegacyFipsThrow” to “true”.
Windows Forms – Accessibility Enhancements
In .NET Framework WinForms is adding three new features khổng lồ enable developers lớn write more accessible applications. The features added are intended to make communication of application data khổng lồ visually impaired users more robust. We’ve sầu added tư vấn for ToolTips when a user navigates via the keyboard, we’ve sầu added LiveRegions and Notification Events to many commonly used controls.
To enable these features your application needs to lớn have sầu the following AppContextSwitches enabled in the App.config file:
Windows Forms – UIA LiveRegions Support in Labels and StatusStrips
UIA Live Regions allow application developers to lớn notify screen readers of a text change on a control that is located apart from the location where the user is working. Examples of where this would come in handy could be a StatusStrip that shows a connection status. If the connection is dropped and the Status changes, the developer might want to notify the screen reader of this change. Windows Forms has implemented UIA LiveRegions for both the Label control & the StatusStrip control.
Example use of the LiveRegion in a Label Control:
Narrator will now announce “Ready” Regardless of where the user is interacting with the application.You can also implement your UserControl as a Live sầu region:
Windows Forms – UIA Notification Events
In Windows 10 Fall Creators Update Windows introduced a new method of having an application notify Narrator that content has changed, and Narrator should announce the change. The UIA Notification sự kiện provides a way for your ứng dụng to lớn raise a UIA event which leads lớn Narrator simply making an announcement based on text you supply with the sự kiện, without the need to have sầu a corresponding control in the UI. In some scenarquả táo, this could be a straightforward way lớn dramatically improve the accessibility of your tiện ích. For more information about UIA Notification Events, see this blog post.
An example of where a Notification might come in handy is khổng lồ notify the progress of some process that may take some time.
An example of raising the Notification event:
Windows Forms – ToolTips on keyboard access
Currently a control tooltip can only be triggered to lớn pop up by moving a mouse pointer into the control. This new feature enables a keyboard user khổng lồ trigger a control’s tooltip by focusing the control using a Tab key or arrow keys with or without modifier keys. This particular accessibility enhancement requires an additional AppContextSwitch as seen in the following example:Create a new WinForms applicationAdd the following XML to lớn the App.config fileAdd several buttons và a ToolTip control to lớn the application’s khung.Set tooltips for the buttons.Run the application & navigate between the buttons using a keyboard:
Windows Forms – DataGridView control accessible hierarchy changes
Currently the accessible hierarchy (UI Automation tree) shows the editing box tree element as a child of currently edited cell but not as a root child element of DataGridView. The hierarchy tree update can be observed using Inspect tool:
WCF – ServiceHealthBehavior
Health endpoints have sầu many benefits và are widely used by orchestration tools to lớn manage the service based on the service health status. Health checks can also be used by monitoring tools to lớn traông chồng và alert on the availability & performance of the service, where they serve as early problem indicators.
ServiceHealthBehavior is a WCF service behavior that extends IServiceBehavior. When added to lớn the ServiceDescription.Behaviors collection, it will enable the following:Return service health status with HTTP. response codes: One can specify in the query string the HTTPhường. status code for a HTTP/GET health probe request.Publication of service health: Service specific details including service state and throttle counts & capađô thị are displayed using an HTTP/GET request using the “?health” query string. Knowing và easily having access to lớn the information displayed is important when trouble-shooting a mis-behaving WCF service.
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Complete release notes can be found here.