Unlike many other programming languages (C, C++, Pascal, etc.), C# provides garbage collection. Your objects are automatically destroyed when you are done with them. You do not need to worry about cleaning up after your objects unless you use unmanaged resources. An unmanaged resource is an operating-system feature outside of the .NET Framework, such as a file handle or a database connection.
If you do control an unmanaged resource, you need to explicitly free that resource when you are done with it. Implicit control over this resource is provided with a destructor, which is called by the garbage collector when your object is destroyed. Note that this material is fairly advanced; it is included here for completeness.
You declare a C# destructor with a tilde as follows:
~MyClass(){} It is not legal to call a destructor explicitly — your destructor will be called by the garbage collector. If you do handle precious unmanaged resources (such as file handles) that you want to close and dispose of as quickly as possible, you ought to implement the IDisposable interface.
The IDisposable interface requires you to create a method named Dispose(), which will be called by your clients.
If you provide a Dispose() method, you should stop the garbage collector from calling your object's destructor. To stop the garbage collector, call the static method GC.SuppressFinalize(), passing in the this reference for your object. Your destructor can then call your Dispose() method.
For some objects, you'd rather have your clients call the Close() method. (For example, Close makes more sense than Dispose() for file objects.) You can implement this by creating a private Dispose() method and a public Close() method and having your Close() method invoke Dispose().
Because you cannot be certain that your user will call Dispose() reliably, and because finalization is nondeterministic (i.e., you can't control when the GC will run), C# provides a using statement to ensure that Dispose() is called at the earliest possible time. The idiom is to declare which objects you are using and then to create a scope for these objects with curly braces. When the close brace is reached, the Dispose() method will be called on the object automatically.
DAY 1 MICROSOFT DOT NET FRAME WORKDAY 2 MICROSOFT DOT NET BASE CLASS LIBRARY
DAY 3 MICROSOFT DOT NET CLASSES AND STRECTURES
DAY 4 METHODS IN FRAME WORK
DAY 5 INPUT VALIDATIONS IN DOT NET PART ONE
DAY 6 INPUT VALIDATIONS IN DOT NET PART TWO
DAY 7 DATA TYPES IN DOT NET
DAY 8 DATA TYPES IN DOT NET PART TWO
DAY 9 IMPLEMENTING PROPERTIES IN DOT NET
DAY 10 DELEGATES AND EVENTS
DAY 11 OOPS INTRODUCTION
DAY 12 POLYMORPHISM
DAY 13 INHERITANCE AND POLYMORPHISM
DAY 14 EBUGGING TOOLS IN DOT NET
DAY 15 DEBUG AND TRACE IN CLASSES
DAY 16 UNIT TEST PLAN
DAY 17 EXCEPTIONS IN VISUAL STUDIO
DAY 19 ADO.NET INTRODUCTION
DAY 20 DATA ACCESSING IN DOT NET
DAY 21 DATA BASE OBJECTS
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