System.NullReferenceException Class
Information   Base Types   Related Resources

The exception that is thrown when there is an attempt to dereference a null object reference.

  • Namespace: System
  • First seen in: .NET v1.0.3705
  • Last seen in: .NET v1.1.4322
  • Last changed in: .NET v1.0.3705
  • Assembly: mscorlib.dll

  • System.SystemException
  • View this type on MSDN
  • View this type on WinFX 247
    Articles (28)Discussions (1032)MembersRotorChanges
    Articles

    Page: 12
    .NET Matters: Const in C#, Exception Filters, IWin32Window, and More
    MSDN
    Const in C#, Exception Filters, IWin32Window, and More
    BETA-PRB: CommandBuilder Changes Modified Commands Back to Original (Q310366)
    Microsoft Support
    The CommandBuilder object may rebuild a command that you try to modify during the next call to the DataAdapter.Update method, and your changes to the command may be lost.
    BETA-PRB: Error "Unhandled Exception of Type System.NullReferenceException Occurred in CommandBuilder" (Q310367)
    Microsoft Support
    If you use the CommandBuilder object to explicitly get commands for the DataAdapter object as follows you can receive the following error message: "An unhandled exception of type 'System.NullReferenceException' occurred in commandbuilder (projectname).exe. Additional information: Value null was found where an instance of an object was required."
    BUG: "System.NullReferenceException" exception while using the vector<bool> class
    http://www.kbalertz.com/
    (837698) - Discusses a bug in template class vector<bool> that causes a "System.NullReferenceException" exception and explains how to resolve this bug by correcting the code in vector file.
    BUG: DataSet Does Not Load Original Records of DiffGram Correctly (Q319919)
    Microsoft Support
    Under the following circumstances
    BUG: Varying errors may occur when you try to call managed code from unmanaged code in Visual C++ .NET 2003
    http://www.kbalertz.com/
    (837318) - Explains that an error message may occur when you try to call managed code from unmanaged code in Visual C++ .NET 2003. Explains that the error occurs if your application contains unmanaged code and uses multiple application domains.
    Creating a Singleton Service with Visual Studio .NET
    MSDN
    A common design pattern that I've seen used is the creation of a COM singleton that resides in a service. A service is a long-running executable that does not support a user interface, and which might not run under the logged-on user account. The service can run without any user being logged on to the computer. This makes services ideal for use on a server or whenever you need functionality that does not interfere with other users who are working on the same computer.
    Detecting File Encodings in .NET
    DevHood
    So you need to read data from a text file, or possibly even a binary file? Do you need to read one byte or two for character arrays, a.k.a. strings? This is a common problem with anything file I/O operations today, especially since the de facto file encoding is Unicode these days, but applications must usually be able to work with older file formats and encodings, which are probably still ASCII files. You need a way to detect what the file encoding is, or leave it to the user to decide (and we all know how well that works!). This tutorial will cover basic detection routines and give you some sample code that you can use in your applications to (usually) detect what the file encoding is.
    DOC: Incorrect Code Sample in "SqlDataAdapter.UpdateCommand Property" Documentation
    Microsoft Support
    (319387) - The SqlDataAdapter.UpdateCommand Property MSDN documentation and the "SqlDataAdapter.UpdateCommand Property" topic in the Microsoft Visual Studio .NET Help documentation describe how to get or how to set a Transact-SQL statement to update records in a...
    FIX: ASP.NET returns a "NullReferenceException" error message when you use SQL Server Session state and you turn on the OutPutCaching feature
    http://www.kbalertz.com/
    (831382) - When you use the Microsoft SQL Server Session state, and you turn on the OutPutCaching feature for a Web page, if you set the Location attribute to Client (<%@ OutputCache Location="Client" Duration="900" VaryByParam="WaitMessage" %>), a user may...
    FIX: Invalid Object in ASP Session State
    http://www.kbalertz.com/
    (810245) - A Microsoft .NET-connected Web application stores a Component Object Model (COM) object in the session state. When you leave the application idle for 12 to 20 minutes, and then you try to gain access to the COM object again, you may receive an invalid...
    FIX: Invalid Object in ASP Session State
    Microsoft Support
    (810245) - A Microsoft .NET-connected Web application stores a Component Object Model (COM) object in the session state. When you leave the application idle for 12 to 20 minutes, and then you try to gain access to the COM object again, you may receive an invalid...
    How to create and use static members by using Visual C++ .NET
    Microsoft Support
    (815704) - How to declare and use properties, fields and functions inside the classes that are static and how to access these class members.
    How to create and use static members by using Visual C++ .NET
    http://www.kbalertz.com/
    (815704) - How to declare and use properties, fields and functions inside the classes that are static and how to access these class members.
    How to obtain unmanaged stack information from a managed block of code in Microsoft Visual Studio .NET
    http://www.kbalertz.com/
    (841888) - Describes how to handle exceptions that were generated in unmanaged code in Microsoft Visual Studio .NET with managed code.
    How to obtain unmanaged stack information from a managed block of code in Microsoft Visual Studio .NET
    http://www.kbalertz.com/
    (841888) - Describes how to handle exceptions that were generated in unmanaged code in Microsoft Visual Studio .NET with managed code.
    How to use the Hashtable collection in Visual C++ .NET
    http://www.kbalertz.com/
    (815673) - This step-by-step article describes how to use the Hashtable collection. By using hashing to retrieve the data, you do not have to use the costly searching mechanism. Hashing uses the value of the key itself to locate the data. The Base Class...
    How to use the Hashtable collection in Visual C++ .NET
    Microsoft Support
    (815673) - This step-by-step article describes how to use the Hashtable collection. By using hashing to retrieve the data, you do not have to use the costly searching mechanism. Hashing uses the value of the key itself to locate the data. The Base Class...
    Messaging Between Threads using Message Loop
    C# Corner
    MessageLoopLib is a stripped down version of a complete, threading communication subsystem I’ve written. This implementation is a single thread created in the GUI constructor. I’ve dropped all thread management and have had to change some of the message code to accommodate this.
    Microsoft Content Management Server Thumbnail Images Placeholder
    The Code Project
    An XML placeholder control that displays thumbnails of images in a Resource Gallery.
    Microsoft Content Management Server Thumbnail Images Placeholder (C#)
    The Code Project
    An XML placeholder control that displays thumbnails of images in a Resource Gallery.
    PRB: "Unhandled Exception of Type 'System.NullReferenceException'" Error Message When You Use CommandBuilder
    http://www.kbalertz.com/
    (310367) - If you use the CommandBuilder object to explicitly get commands for the DataAdapter object as follows: da.InsertCommand = cb.GetInsertCommand and then run the following Visual Basic .NET code cb.DataAdapter = Nothing or the following Visual C# .NET...
    Publish And Subscribe
    The Code Project
    This tutorial will introduce the concepts of publishing and subscribing data over a network using the C# programming language and will hopefully provide not only an understanding of how publish and subscribe applications work but should provide the reader with the tools needed to develop a publish and subscribe style application of their own.
    Rich Custom Error Handling with ASP.NET
    MSDN
    Add your own custom error handling to your ASP.NET Web applications to ease debugging and improve customer satisfaction.
    Using the Try...Catch...Finally Statement
    DotNetJunkies
    Structured error handling will be a completely new concept to Visual Basic and VBScript developers. Since the .NET Framework requires the use of Strong Typed Languages, such as Visual Basic it is time to learn how to use this method of error handling.
    Ad
    MBR BootFX
    Best-of-breed application framework for .NET projects, developed by Matthew Baxter-Reynolds and MBR IT
     
     Copyright © Matthew Baxter-Reynolds 2001-2008. '.NET 247 Software Development Services' is a trading style of MBR IT Solutions Ltd.
    Contact Us - Terms of Use - Privacy Policy - www.dotnet247.com