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Download the Breaking Changes in Visual Studio and the .NET Framework document.

Breaking Changes Overview

.NET Framework Version 2.0

• Threading Cancellation Functionality
• INullableValue Interface
• System.Nullable<T>
• Boxing and Unboxing of Nullable<T>

.NET Client

• MenuCommands Class
• Behavior Class
• ColumnWidthChangedEventArgs Class
• BindingContext Class
• DataGridViewRow Class
• DataGridViewCell Class
• Client Application User Settings
• Application Settings Serialization
• TreeView and TreeNode Classes
• BackgroundWorker Class
• MaskedTextBox Class
• GetPreferredSize Property of Form Controls
• Windows Forms API Changes
• CancelRowEdit Event
• AsyncCompletedEventArgs.Error Property
• RadioButton.TabStop Property
• MDI Automatic Merging
• BindingSource.Items Property

.NET Compact Framework

• EventArgs Classes

Common Language Runtime (CLR)

• XCertificateUI Class
• System.Threading.Thread Class
• KeyValuePair Class
• AssembliesVisibleTo Attribute

System.Data Namespace

• SqlDataReader.GetSchemaTable Method
• SqlNotificationEncryptionType Enumeration
• System.Data.SqlTypes.SqlStreamChars Property
• SqlDataReader.GetSqlValue Return Type

Globalization

• Persian Calendar Class
• DateTimeFormatInfo Class

Visual Studio Tools for Office

• VSTView Interface

Visual C++ Programming Language

• ATL Server — CAtlHttpClient Class
• Floating-point Control Word Support Functions
• Dynamic Cast from Private Base
• MFC Wrapper for LoadLibraryEx()
• MFC -bit Message Map Support

C# Programming Language

• Compilation Error Due to Implicit Conversion
• Checked and Unchecked Expressions
• Nullable<T> Does Not Satisfy IComparable Constraint Error
• Cannot Form a Delegate Over Nullable<T> Error
• Operator "is" Returns true for T and Non-null T?

Visual Basic Programming Language

• TypeOf Statement
• Non-CLS Compliant Return Types
• Overriding Object Members in Structures
• Namespaces with Different Casing
• Implementing MustOverride Methods
• AppActivate Case-insensitivity
• AppActivate Right-Hand Title
• CreateObject Case-insensitivity
• Zero-Based Collection Object
• FileIO Enumerations
• FileLogTraceListener.CustomLocation Property
• FileLogTraceListener Date Format

ClickOnce Runtime Process

• ClickOnce Store Change
• WebBrowser Permissions

Visual Studio

• Visual Studio Settings
• Machine.config File Changes
• Visual C++ Beta Project Open Error
• Errors When Deploying Device Projects to the Device Emulator

ASP.NET

• Unique Class Names
• HTML Default Validation Schema
• Events for Non-Visible Controls
• ICallbackEventHandler.GetCallbackResult Method
• ASP.NET Personalization Database Schema
• Page.CreateStateFormatter Method
• Aspnet_regiis.exe Utility Argument Change
• WebPart File Format
• System.Web.UI.IPageHeader
• Relative References in the Configuration File
• Web Project Global Settings and Project Policy Settings