អត្ថបទនេះត្រូវបានសរសេរជាភាសាផ្សេង ដែលមិនមែនជាភាសាខ្មែរ។ បើសិនជាអត្ថបទទុកសម្រាប់អ្នកអានមកពី សហគមន៍នៃភាសាមួយនេះ វាគួរតែចែកចាយទៅវិគីភីឌាជាភាសានោះ។ សូមមើល បញ្ជីនៃគម្រោងវិគីភីឌាទាំងអស់។
អត្ថបទនេះត្រូវការបកប្រែទៅជាភាសាខ្មែរ។ សូមមើល ច្រកចូលអត្ថបទនេះ លើក្រុមទំព័រដែលត្រូវការបំណកប្រែទៅជាភាសាខ្មែរ ដើម្បីពិភាក្សា ។ ប្រសិនបើ អត្ថបទមិនត្រូវបានសរសេរជាភាសាខ្មែរឡើងវិញទេ ក្នុងរយៈពេលពីរសប្ដាហ៍ទៀត អត្ថបទនឹងត្រូវចុះបញ្ជីដើម្បីលុបចោល និង/ឬ ប្ដូរវាទៅកាន់វិគីភីឌាជាភាសាដើមរបស់វាវិញ ។ បើសិនជាលោកអ្នក គ្រាន់តែចង់បិទស្លាកទំព័រនេះត្រូវការបំណកប្រែ សូមបញ្ចូល {{អាទេស.:ត្រូវការបកប្រែ | ទំ. = ស៊ីទ្រុងជ្រូក | ភាសា = មិនស្គាល់ | ផ្ដល់យោបល់ = }} ~~~~ ទៅខាងក្រោម នៃផ្នែក នៃក្រុមទំព័រនេះត្រូវការបំណកប្រែទៅជាភាសាខ្មែរ ។ |
C# (បញ្ចេញសំឡេង ស៊ីឝាប)គឺជាភាសាកម្មវិធីពហុគំរូមួយដែលដាក់បញ្ចូលក្បួនកម្មវិធីកិច្ចការដាក់ប្រភេទខ្លាំង អាជ្ញាបញ្ជា ប្រតិវេទ មុខងារ ប្រភេទ តម្រង់កម្មវត្ថុ ពឹងផ្អែកថ្នាក់ និងតម្រង់ទៅសមាសភាគ។ វាត្រូវបានអភិវឌ្ឍដោយម៉ៃក្រូសបក្នុង.NET (ដតណិត)ដែលផ្ដើមនិងក្រោយមកបានយល់ស្របថាជាមាត្រដ្ឋានដោយស.ស.គ.អ. រឺ Ecma (ECMA-៣៣៤) និងអ.ម.អ. រឺ ISO (ISO/IEC 23270:2006)។ C# គឺជាមួយក្នុងចំណោមភាសាកម្មវិធីដេលបានរចនាសម្រាប់ហេដ្ឋារចនាសម្ព័ន្ធភាសាសាមញ្ញ។
បរាទិស | ពហុគំរូ: មានរចនាសម្ព័ន្ធ អាជ្ញា តម្រង់កម្មវត្ថុ បើកព្រឹត្តិការណ៍ មុខងារ ប្រភេទ ឆ្លុះបញ្ចាំង |
---|---|
អំបូរ | C |
រចនាដោយ | ម៉ៃក្រូសប |
អភិវឌ្ឍនករ | ម៉ៃក្រូសប |
ចេញដំបូង | ២០០០, ១៦ ឆ្នាំកន្លងទៅ |
ផ្សាយថេរ | ៥.០ / August 15, 2012 |
ក្បួនកំណត់ប្រភេទ | ឋិតិវន្ត ថាមវន្ត ខ្លាំង សុវត្ថិភាព ធម្មតា សន្និដ្ឋានអន្លើៗ |
វេទិកា | ហេដ្ឋារចនាសម្ព័ន្ធភាសាសាមញ្ញ |
ប.ក. | Cross-platform |
អាជ្ញាបណ្ណ | ព.ភ.ស.គឺជាកម្មសិទ្ធិករ អ្នកចងក្រងម៉ូណូគឺជាអ.ស.ទ.ក៣ទ្វេគុណ MIT/X១១និងបណ្ណាល័យជាអ.ស.ទ.ត.កំ២ ដតហ៊្គ្នូគឺជាអ.ស.ទ.ទ្វេគុណនិងអ.ស.ទ.ត.កំ២ |
កន្ទុយឈ្មោះសំណុំសារ | .cs (ដតស៊ីអ៊ែស) |
ស្ថានីយ៍បណ្ដាញ | https://docs.microsoft.com/de-de/dotnet/csharp/, https://docs.microsoft.com/ja-jp/dotnet/csharp/, https://docs.microsoft.com/fr-fr/dotnet/csharp/, https://docs.microsoft.com/it-it/dotnet/csharp/ docs.microsoft.com/en-us/dotnet/csharp/, https://docs.microsoft.com/de-de/dotnet/csharp/, https://docs.microsoft.com/ja-jp/dotnet/csharp/, https://docs.microsoft.com/fr-fr/dotnet/csharp/, https://docs.microsoft.com/it-it/dotnet/csharp/ |
Major implementations | |
វីស៊្យូអ៊ែលC# .ណេតភ្វ្រែមវ៉ឺខ ម៉ូណូ ដតហ៊្គ្នូ | |
Dialects | |
Cω ស្ប៉ិក# C#ពហុសព្ទ | |
Influenced by | |
C++ អេផ្វផ្វល ជ្វា ម៉ដជូឡេ-៣ ប៉ាស់ស្កាល់វត្ថុ | |
Influenced | |
D F# ណេមម៉្រល វ៉ាល់ឡា | |
|
C# ត្រូវបានទុកបម្រុងជាភាសាកម្មវិធីធម្មតា ទំនើប គោលបំណងទូទៅ តម្រែតម្រង់កម្មវត្ថុមួយ។ ក្រុមអភិវឌ្ឍន៍របស់វាគឺដឹកនាំដោយលោកអានណឺស-ហាអ៊ិចស្ពាំក។ កំណែថ្មីបំផុតគឺC#៥.០ ដែលត្រូវបានដាក់ឱ្យប្រើឡើងវិញនៅថ្ងៃ ១៥សីហា ២០១២។
មាត្រដ្ឋានស.ស.គ.អ.ចុះបញ្ជីគោលដៅរចនាទាំងនេះសម្រាប់C#:
The name "C sharp" was inspired by musical notation where a sharp indicates that the written note should be made a semitone higher in pitch. This is similar to the language name of C++, where "++" indicates that a variable should be incremented by 1.
Due to technical limitations of display (standard fonts, browsers, etc.) and the fact that the sharp symbol (U+266F ♯ MUSIC SHARP SIGN (♯)) is not present on the standard keyboard, the number sign (U+0023 # NUMBER SIGN (#)) was chosen to represent the sharp symbol in the written name of the programming language. This convention is reflected in the ECMA-334 C# Language Specification. However, when it is practical to do so (for example, in advertising or in box art), Microsoft uses the intended musical symbol.
The "sharp" suffix has been used by a number of other .NET languages that are variants of existing languages, including J# (a .NET language also designed by Microsoft that is derived from Java 1.1), A# (from Ada), and the functional programming language F#. The original implementation of Eiffel for .NET was called Eiffel#, a name retired since the full Eiffel language is now supported. The suffix has also been used for libraries, such as Gtk# (a .NET wrapper for GTK+ and other GNOME libraries), Cocoa# (a wrapper for Cocoa) and Qt# (a .NET language binding for the Qt toolkit).
C# មានវាក្យសម្ព័ន្ធដូចខាងក្រោម៖
By design, C# is the programming language that most directly reflects the underlying Common Language Infrastructure (CLI).[ត្រូវការអំណះអំណាង] Most of its intrinsic types correspond to value-types implemented by the CLI framework. However, the language specification does not state the code generation requirements of the compiler: that is, it does not state that a C# compiler must target a Common Language Runtime, or generate Common Intermediate Language (CIL), or generate any other specific format. Theoretically, a C# compiler could generate machine code like traditional compilers of C++ or Fortran.
Some notable features of C# that distinguish it from C and C++ (and Java, where noted) are:
bool
. Statements that take conditions, such as while
and if
, require an expression of a type that implements the true
operator, such as the boolean type. While C++ also has a boolean type, it can be freely converted to and from integers, and expressions such as if(a)
require only that a
is convertible to bool, allowing a
to be an int, or a pointer. C# disallows this "integer meaning true or false" approach, on the grounds that forcing programmers to use expressions that return exactly bool
can prevent certain types of common programming mistakes in C or C++ such as if
(a = b)
(use of assignment =
instead of equality ==
).System.IntPtr
type, but it cannot dereference them.try...catch
construct to handle exceptions, C# has a try...finally
construct to guarantee execution of the code in the finally
block, whether an exception occurs or not.C# has a unified type system. This unified type system is called Common Type System (CTS).
A unified type system implies that all types, including primitives such as integers, are subclasses of the System.Object
class. For example, every type inherits a ToString()
method.
CTS separates data types into two categories:
Instances of value types do not have referential identity nor referential comparison semantics - equality and inequality comparisons for value types compare the actual data values within the instances, unless the corresponding operators are overloaded. Value types are derived from System.ValueType
, always have a default value, and can always be created and copied. Some other limitations on value types are that they cannot derive from each other (but can implement interfaces) and cannot have an explicit default (parameterless) constructor. Examples of value types are all primitive types, such as int
(a signed 32-bit integer), float
(a 32-bit IEEE floating-point number), char
(a 16-bit Unicode code unit), and System.DateTime
(identifies a specific point in time with nanosecond precision). Other examples are enum
(enumerations) and struct
(user defined structures).
In contrast, reference types have the notion of referential identity - each instance of a reference type is inherently distinct from every other instance, even if the data within both instances is the same. This is reflected in default equality and inequality comparisons for reference types, which test for referential rather than structural equality, unless the corresponding operators are overloaded (such as the case for System.String
). In general, it is not always possible to create an instance of a reference type, nor to copy an existing instance, or perform a value comparison on two existing instances, though specific reference types can provide such services by exposing a public constructor or implementing a corresponding interface (such as ICloneable
or IComparable
). Examples of reference types are object
(the ultimate base class for all other C# classes), System.String
(a string of Unicode characters), and System.Array
(a base class for all C# arrays).
Both type categories are extensible with user-defined types.
Boxing is the operation of converting a value-type object into a value of a corresponding reference type. Boxing in C# is implicit.
Unboxing is the operation of converting a value of a reference type (previously boxed) into a value of a value type. Unboxing in C# requires an explicit type cast. A boxed object of type T can only be unboxed to a T (or a nullable T).
Example:
int foo = 42; // Value type. object bar = foo; // foo is boxed to bar. int foo2 = (int)bar; // Unboxed back to value type.
Generics were added to version 2.0 of the C# language. Generics use type parameters, which make it possible to design classes and methods that do not specify the type used until the class or method is instantiated. The main advantage is that one can use generic type parameters to create classes and methods that can be used without incurring the cost of runtime casts or boxing operations, as shown here:
// Declare the generic class. public class GenericList<T> { void Add(T input) { } } class TestGenericList { private class ExampleClass { } static void Main() { // Declare a list of type int. GenericList<int> list1 = new GenericList<int>(); // Declare a list of type string. GenericList<string> list2 = new GenericList<string>(); // Declare a list of type ExampleClass. GenericList<ExampleClass> list3 = new GenericList<ExampleClass>(); } }
C# features "preprocessor directives" (though it does not have an actual preprocessor) based on the C preprocessor that allow programmers to define symbols, but not macros. Conditionals such as #if
, #endif
, and #else
are also provided. Directives such as #region
give hints to editors for code folding.
public class Foo { #region Constructors public Foo() {} public Foo(int firstParam) {} #endregion #region Procedures public void IntBar(int firstParam) {} public void StrBar(string firstParam) {} public void BoolBar(bool firstParam) {} #endregion }
C# utilizes a double slash (//
) to indicate the rest of the line is a comment. This is inherited from C++.
public class Foo { // a comment public static void Bar(int firstParam) {} // also a comment }
Multi-line comments can start with slash-asterisk (/*
) and end asterisk-slash (*/
). This is inherited from standard C.
public class Foo { /* A Multi-Line comment */ public static void Bar(int firstParam) {} }
C#'s documentation system is similar to Java's Javadoc, but based on XML. Two methods of documentation are currently supported by the C# compiler.
Single-line documentation comments, such as those commonly found in Visual Studio generated code, are indicated on a line beginning with ///
.
public class Foo { /// A summary of the method. /// A description of the parameter. /// Remarks about the method. public static void Bar(int firstParam) {} }
Multi-line documentation comments, while defined in the version 1.0 language specification, were not supported until the .NET 1.1 release. These comments start with slash-asterisk-asterisk (/**
) and end asterisk-slash (*/
).
public class Foo { /** A summary of the method. * A description of the parameter. * Remarks about the method. */ public static void Bar(int firstParam) {} }
Note there are some stringent criteria regarding white space and XML documentation when using the slash/asterisk/asterisk (/**
) technique.
This code block:
/** * * A summary of the method.*/
produces a different XML comment from this code block:
/** * A summary of the method.*/
Syntax for documentation comments and their XML markup is defined in a non-normative annex of the ECMA C# standard. The same standard also defines rules for processing of such comments, and their transformation to a plain XML document with precise rules for mapping of CLI identifiers to their related documentation elements. This allows any C# IDE or other development tool to find documentation for any symbol in the code in a certain well-defined way.
The C# specification details a minimum set of types and class libraries that the compiler expects to have available. In practice, C# is most often used with some implementation of the Common Language Infrastructure (CLI), which is standardized as ECMA-335 Common Language Infrastructure (CLI).
The following is a very simple C# program, a version of the classic "Hello world" example:
using System; class Program { static void Main() { Console.WriteLine("Hello world!"); } }
The effect is to write the following text to the output console:
Hello world!
បន្ទាត់នីមួយៗមានគោលបំណង៖
using System;
The above line of code tells the compiler to use System
as a candidate prefix for types used in the source code. In this case, when the compiler sees use of the Console
type later in the source code, it tries to find a type named Console
, first in the current assembly, followed by all referenced assemblies. In this case the compiler fails to find such a type, since the name of the type is actually System.Console
. The compiler then attempts to find a type named System.Console
by using the System
prefix from the using
statement, and this time it succeeds. The using
statement allows the programmer to state all candidate prefixes to use during compilation instead of always using full type names.
class Program
Above is a class definition. Everything between the following pair of braces describes Program
.
static void Main()
This declares the class member method where the program begins execution. The .NET runtime calls the Main
method. (Note: Main
may also be called from elsewhere, like any other method, e.g. from another method of Program
.) The static
keyword makes the method accessible without an instance of Program
. Each console application's Main
entry point must be declared static
. Otherwise, the program would require an instance, but any instance would require a program. To avoid that irresolvable circular dependency, C# compilers processing console applications (like that above) report an error, if there is no static Main
method. The void
keyword declares that Main
has no return value.
Console.WriteLine("Hello world!");
This line writes the output. Console
is a static class in the System
namespace. It provides an interface to the standard input, output, and error streams for console applications. The program calls the Console
method WriteLine
, which displays on the console a line with the argument, the string "Hello world!"
.
A GUI example:
using System.Windows.Forms; class Program { static void Main() { MessageBox.Show("Hello world!"); } }
This example is similar to the previous example, except that it generates a dialog box that contains the message "Hello world!" instead of writing it to the console.
In August 2000, Microsoft Corporation, Hewlett-Packard and Intel Corporation co-sponsored the submission of specifications for C# as well as the Common Language Infrastructure (CLI) to the standards organization Ecma International. In December 2001, ECMA released ECMA-334 C# Language Specification. C# became an ISO standard in 2003 (ISO/IEC 23270:2003 - Information technology — Programming languages — C#). ECMA had previously adopted equivalent specifications as the 2nd edition of C#, in December 2002.
In June 2005, ECMA approved edition 3 of the C# specification, and updated ECMA-334. Additions included partial classes, anonymous methods, nullable types, and generics (similar to C++ templates).
In July 2005, ECMA submitted the standards and related TRs to ISO/IEC JTC 1 via the latter's Fast-Track process. This process usually takes 6–9 months.
The C# language definition and the CLI are standardized under ISO and Ecma standards that provide reasonable and non-discriminatory licensing protection from patent claims. However, Microsoft uses C# and the CLI in its Base Class Library (BCL) that is the foundation of its proprietary .NET framework, and which provides a variety of non-standardized classes (extended I/O, GUI, Web services, etc.). Some cases where Microsoft patents apply to standards used in the .NET framework are documented by Microsoft and the applicable patents are available on either RAND terms or through Microsoft's Open Specification Promise that releases patent rights to the public, but there is some concern and debate as to whether there are additional aspects patented by Microsoft that are not covered, which may deter independent implementations of the full framework.
Microsoft has agreed not to sue open source developers for violating patents in non-profit projects for the part of the framework that is covered by the OSP. Microsoft has also agreed not to enforce patents relating to Novell products against Novell's paying customers with the exception of a list of products that do not explicitly mention C#, .NET or Novell's implementation of .NET (The Mono Project). However, Novell maintains that Mono does not infringe any Microsoft patents. Microsoft has also made a specific agreement not to enforce patent rights related to the Moonlight browser plugin, which depends on Mono, provided it is obtained through Novell.
In a note posted on the Free Software Foundation's news website in June 2009, Richard Stallman warned that he believes that "Microsoft is probably planning to force all free C# implementations underground some day using software patents", and recommended that developers avoid taking what he described as the "gratuitous risk" associated with "depend[ing] on the free C# implementations". The Free Software Foundation later reiterated its warnings, claiming that the extension of Microsoft Community Promise to the C# and the CLI ECMA specifications would not prevent Microsoft from harming free implementations of C#, because many specific Windows libraries included with .NET or Mono were not covered by this promise.
The reference C# compiler is Microsoft Visual C#, which is closed-source.
Other C# compilers exist, often including an implementation of the Common Language Infrastructure and the .NET class libraries up to .NET 2.0:
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ទំព័រគំរូ:Ecma International Standards
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