Using APIs in C#

i did chose this topic from the CSharp Friends forums ,to share it here because of it’s importance, i left the whole topic as is without changing any this but the style of the code listing.
by: vbguyny

APIs (Application Programming Interface) are used in many higher level programming languages to directly make a call to a function inside a DLL (Dynamic Linked Library) which was designed in C++. APIs increase the efficiency of programs that use algorithms with many mathematical computations.

Syntax

When declaring APIs in C#, use the following syntax:

Example

Making a program that uses the windows API PlaySound.

The following example demonstrates how to implement the Windows API PlaySound in a C# application
Notice that the API is declared inside the class clsAPI.

Where to Find APIs

list of all the Windows APIs can be found in the API Text Viewer that comes with VB6. The C++ .NET documentation provides help on how to use each API function.

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