C sharp file extension

Csharp what is file extension of c sharp

C# allows you to work with the directories and files using various directory and file related classes such as the DirectoryInfo class and the FileInfo class. 5 Extension Gets the string representing the file extension. 6 FullName Gets the full path of the file. 7 LastAccessTime Gets the time the current file was last accessed. 8 LastWriteTime Gets the time of the last written activity of the file. 9 Length Gets the size, in bytes, of the current file.

Extend File Class

System.IO.FileInfo f1 = new System.IO.FileInfo("c:\\myfile.txt").Length 

or you can extend the FileInfo class

public static string GetFileSize(this FileInfo fi) < long Bytes = fi.Length; if (Bytes >= 1073741824) < Decimal size = Decimal.Divide(Bytes, 1073741824); return String.Format("GB", size); > else if (Bytes >= 1048576) < Decimal size = Decimal.Divide(Bytes, 1048576); return String.Format("MB", size); > else if (Bytes >= 1024) < Decimal size = Decimal.Divide(Bytes, 1024); return String.Format("KB", size); > else if (Bytes > 0 & Bytes < 1024) < Decimal size = Bytes; return String.Format("Bytes", size); > else < return "0 Bytes"; >> 

 System.IO.FileInfo f1 = new System.IO.FileInfo("c:\\myfile.txt"); var size = f1.GetFileSize(); 

No, but you can just create your own static class and put your methods there. Given that you are basically producing a summary string for your user interface, I wouldn’t think that it would belong within the File class anyway (even if you could put it there — which you can’t).

File is a static class and cannot be extended. Use something like FileEx instead.

string s = FileEx.GetFileSize("something.txt"); 

Determine the file type using C#, you can use Myrmec to identify the file type, this library use the file byte head. this library avaliable on nuget «Myrmec»,and this is the repo, myrmec also support mime type,you can try it. the code will like this : // create a sniffer instance.

C# — Windows File System

C# allows you to work with the directories and files using various directory and file related classes such as the DirectoryInfo class and the FileInfo class.

The DirectoryInfo Class

The DirectoryInfo class is derived from the FileSystemInfo class. It has various methods for creating, moving, and browsing through directories and subdirectories. This class cannot be inherited.

Following are some commonly used properties of the DirectoryInfo class −

Gets the attributes for the current file or directory.

Gets the creation time of the current file or directory.

Gets a Boolean value indicating whether the directory exists.

Gets the string representing the file extension.

Gets the full path of the directory or file.

Gets the time the current file or directory was last accessed.

Gets the name of this DirectoryInfo instance.

Following are some commonly used methods of the DirectoryInfo class −

public DirectoryInfo CreateSubdirectory(string path)

Creates a subdirectory or subdirectories on the specified path. The specified path can be relative to this instance of the DirectoryInfo class.

public override void Delete()

Deletes this DirectoryInfo if it is empty.

public DirectoryInfo[] GetDirectories()

Returns the subdirectories of the current directory.

public FileInfo[] GetFiles()

Returns a file list from the current directory.

For a complete list of properties and methods, please visit Microsoft’s C# documentation.

The FileInfo Class

The FileInfo class is derived from the FileSystemInfo class. It has properties and instance methods for creating, copying, deleting, moving, and opening of files, and helps in the creation of FileStream objects. This class cannot be inherited.

Following are some commonly used properties of the FileInfo class −

Gets the attributes for the current file.

Gets the creation time of the current file.

Gets an instance of the directory which the file belongs to.

Gets a Boolean value indicating whether the file exists.

Gets the string representing the file extension.

Gets the full path of the file.

Gets the time the current file was last accessed.

Gets the time of the last written activity of the file.

Gets the size, in bytes, of the current file.

Gets the name of the file.

Following are some commonly used methods of the FileInfo class −

public StreamWriter AppendText()

Creates a StreamWriter that appends text to the file represented by this instance of the FileInfo.

public FileStream Create()

public override void Delete()

Deletes a file permanently.

public void MoveTo(string destFileName)

Moves a specified file to a new location, providing the option to specify a new file name.

public FileStream Open(FileMode mode)

Opens a file in the specified mode.

public FileStream Open(FileMode mode, FileAccess access)

Opens a file in the specified mode with read, write, or read/write access.

public FileStream Open(FileMode mode, FileAccess access, FileShare share)

Opens a file in the specified mode with read, write, or read/write access and the specified sharing option.

public FileStream OpenRead()

Creates a read-only FileStream

public FileStream OpenWrite()

Creates a write-only FileStream.

For complete list of properties and methods, please visit Microsoft’s C# documentation.

Example

The following example demonstrates the use of the above-mentioned classes −

using System; using System.IO; namespace WindowsFileApplication < class Program < static void Main(string[] args) < //creating a DirectoryInfo object DirectoryInfo mydir = new DirectoryInfo(@"c:\Windows"); // getting the files in the directory, their names and size FileInfo [] f = mydir.GetFiles(); foreach (FileInfo file in f) < Console.WriteLine("File Name: Size: ", file.Name, file.Length); > Console.ReadKey(); > > >

When you compile and run the program, it displays the names of files and their respective sizes in the Windows directory.

Check if a path has a file name extension in C, Syntax: public static bool HasExtension (string path); Here, path is the specified path to search for an extension. Returns: This method will return true if the characters that follow the last directory separator (\\ or /) or volume separator (:) in the path include a period (.) followed by one or more characters; otherwise, …

Is file extension c#

string myFilePath = @"C:\MyFile.txt"; string ext = Path.GetExtension(myFilePath); // ext would be ".txt"

What are .CSX C# files for?, NET Compiler Platform, also known by its nickname Roslyn, is a set of open-source compilers and code analysis APIs for C# and Visual Basic .NET languages from Microsoft.] You don’t have to have everything in a class and method, a csx file is like it’s own method, and everything in the file will be …

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Path. Get Extension Метод

Некоторые сведения относятся к предварительной версии продукта, в которую до выпуска могут быть внесены существенные изменения. Майкрософт не предоставляет никаких гарантий, явных или подразумеваемых, относительно приведенных здесь сведений.

Перегрузки

Возвращает расширение из пути к файлу, представленного диапазоном символов только для чтения.

Возвращает расширение указанной строки пути (включая точку «.»).

GetExtension(ReadOnlySpan)

Возвращает расширение из пути к файлу, представленного диапазоном символов только для чтения.

public: static ReadOnlySpan GetExtension(ReadOnlySpan path);

public static ReadOnlySpan GetExtension (ReadOnlySpan path);

static member GetExtension : ReadOnlySpan -> ReadOnlySpan

Public Shared Function GetExtension (path As ReadOnlySpan(Of Char)) As ReadOnlySpan(Of Char)

Параметры

Путь к файлу, из которого необходимо получить расширение.

Возвращаемое значение

Расширение указанного пути (включая точку — «.») или Empty, если в path отсутствуют сведения о расширении.

Комментарии

Этот метод получает расширение path путем поиска path точки («.»), начиная с последнего символа в диапазоне только для чтения и продолжая к первому символу. Если точка найдена до или DirectorySeparatorChar AltDirectorySeparatorChar символа, возвращаемый диапазон только для чтения содержит точку и символы после нее; в противном случае ReadOnlySpan.Empty возвращается.

См. также раздел

Применяется к

GetExtension(String)

Возвращает расширение указанной строки пути (включая точку «.»).

public: static System::String ^ GetExtension(System::String ^ path);

public static string GetExtension (string path);

public static string? GetExtension (string? path);

static member GetExtension : string -> string

Public Shared Function GetExtension (path As String) As String

Параметры

Строка пути, из которой нужно получить расширение.

Возвращаемое значение

Расширение указанного пути (включая точку «.») или значение null или Empty. Если параметр path имеет значение null , GetExtension(String) возвращает null . Если параметр path не содержит сведений о расширении, GetExtension(String) возвращает Empty.

Исключения

платформа .NET Framework и версии .NET Core старше 2.1: path содержит один или несколько недопустимых символов, определенных в GetInvalidPathChars().

Примеры

В следующем примере показано использование GetExtension метода на классической платформе на основе Windows.

String^ fileName = "C:\\mydir.old\\myfile.ext"; String^ path = "C:\\mydir.old\\"; String^ extension; extension = Path::GetExtension( fileName ); Console::WriteLine( "GetExtension('') returns ''", fileName, extension ); extension = Path::GetExtension( path ); Console::WriteLine( "GetExtension('') returns ''", path, extension ); // This code produces output similar to the following: // // GetExtension('C:\mydir.old\myfile.ext') returns '.ext' // GetExtension('C:\mydir.old\') returns '' 

string fileName = @"C:\mydir.old\myfile.ext"; string path = @"C:\mydir.old\"; string extension; extension = Path.GetExtension(fileName); Console.WriteLine("GetExtension('') returns ''", fileName, extension); extension = Path.GetExtension(path); Console.WriteLine("GetExtension('') returns ''", path, extension); // This code produces output similar to the following: // // GetExtension('C:\mydir.old\myfile.ext') returns '.ext' // GetExtension('C:\mydir.old\') returns '' 

Dim fileName As String = "C:\mydir.old\myfile.ext" Dim pathname As String = "C:\mydir.old\" Dim extension As String extension = Path.GetExtension(fileName) Console.WriteLine("GetExtension('') returns ''", fileName, extension) extension = Path.GetExtension(pathname) Console.WriteLine("GetExtension('') returns ''", pathname, extension) ' This code produces output similar to the following: ' ' GetExtension('C:\mydir.old\myfile.ext') returns '.ext' ' GetExtension('C:\mydir.old\') returns '' 

Комментарии

Этот метод получает расширение path путем поиска path точки (.), начиная с последнего символа path и продолжая к первому символу. Если точка найдена до или DirectorySeparatorChar AltDirectorySeparatorChar символа, возвращаемая строка содержит точку и символы после нее; в противном случае String.Empty возвращается.

Список распространенных задач ввода-вывода см. в разделе «Общие задачи ввода-вывода».

См. также раздел

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How to get file extension or file size in C# ? ( Code With Example )

While trying to upload a file in C#, you may need to get file extension or validate file extension from file name in C#, so in this post, I have provided code sample, how you can check file extension or file size before uploading a file in C#.

Get File Extension from file in C#

Let’s take a look at an example, which shows how you can extract file extension from file, in this case we will be using a file which is already on disk. Using FileInfo class we get all the details of the file.

using System; using System.IO; using System.Text; namespace FileSizeAndExtension < public class Program < public static void Main() < // Write Full File name with directory string fileName = @"D:\C#-sample.pdf"; //FileInfo Class to get file details FileInfo fi = new FileInfo(fileName); // Get File Name string GetFileName = fi.Name; Console.WriteLine("File Name: ", GetFileName); // Get file name with complete path string fullFileName = fi.FullName; Console.WriteLine("File Name: ", fullFileName); // Get file extension string extn = fi.Extension; Console.WriteLine("File Extension: ", extn); // Get directory name string directoryName = fi.DirectoryName; Console.WriteLine("Directory Name: ", directoryName); //Check if File Exists bool exists = fi.Exists; Console.WriteLine("File Exists: ", exists); if (fi.Exists) < // Get file size long size = fi.Length; Console.WriteLine("File Size in Bytes: ", size); // Check if File ReadOnly ? bool IsReadOnly = fi.IsReadOnly; Console.WriteLine("Is ReadOnly: ", IsReadOnly); > Console.ReadKey(); > > > 

File Name: C#-sample.pdf File Name: D:\C#-sample.pdf File Extension: .pdf Directory Name: D:\ File Exists: True File Size in Bytes: 10218145 Is ReadOnly: False

In the above code, we already have a file placed in «D:\C#-sample.pdf», and we are getting file details using FileInfo class in C#, which is in namespace «System.IO».

Get File Extension and File Size using C#

In this method, to get file extension, we use Extension property of a file to get it’s extension like .txt, .xlsx etc, and using Length property of the FileInfo class returns the size of a file in bytes.

Let’s take a look at an example to get file size and extension using C#.

using System; using System.IO; using System.Text; namespace FileSizeAndExtension < public class Program < public static void Main() < // Write Full File name with directory string fileName = @"E:\CSharpFile.txt"; //FileInfo Class to get file details FileInfo fi = new FileInfo(fileName); // Create this file using (FileStream fs = fi.Create()) < Byte[] txt = new UTF8Encoding(true).GetBytes("New file."); fs.Write(txt, 0, txt.Length); Byte[] author = new UTF8Encoding(true).GetBytes("Author Vikas lalwani"); fs.Write(author, 0, author.Length); >// Get File Name string GetFileName = fi.Name; Console.WriteLine("File Name: ", GetFileName); // Get file name with complete path string fullFileName = fi.FullName; Console.WriteLine("File Name: ", fullFileName); // Get file extension string extn = fi.Extension; Console.WriteLine("File Extension: ", extn); // Get directory name string directoryName = fi.DirectoryName; Console.WriteLine("Directory Name: ", directoryName); //Check if File Exists bool exists = fi.Exists; Console.WriteLine("File Exists: ", exists); if (fi.Exists) < // Get file size long size = fi.Length; Console.WriteLine("File Size in Bytes: ", size); // Check if File ReadOnly ? bool IsReadOnly = fi.IsReadOnly; Console.WriteLine("Is ReadOnly: ", IsReadOnly); // Creation, last access, and last write time DateTime creationTime = fi.CreationTime; Console.WriteLine("Creation time: ", creationTime); DateTime accessTime = fi.LastAccessTime; Console.WriteLine("Last access time: ", accessTime); DateTime updatedTime = fi.LastWriteTime; Console.WriteLine("Last write time: ", updatedTime); > Console.ReadKey(); > > > 

File Name: CSharpFile.txt File Name: E:\CSharpFile.txt File Extension: .txt Directory Name: E:\ File Exists: True File Size in Bytes: 29 Is ReadOnly: False Creation time: 28/02/2020 20:20:33 Last access time: 28/02/2020 20:20:33 Last write time: 28/02/2020 20:20:33

In the above code, we are using FileInfo to create the file, get file size and extension, but we are also creating it using FileStream.

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