File handling c.net

This sample code uses a FileInfo class to access a file's properties. The properties appear in a ListBox control. This sample code uses the Directory and Drive classes to list the logical drives on a system.

For this sample, the results appear in a ListBox control. This sample code uses the GetDirectories method of the Directory class to obtain a list of folders. This sample code uses the GetFiles method of the Directory class to obtain a listing of files. Many things can go wrong when a user gains access to files. The files may not exist, the files may be in use, or users may not have rights on the files of folders that they're trying to access.

Consider these possibilities when you write code to handle the exceptions that may be generated. On the File menu, point to New , and then click Project. Under Templates section, click Windows Forms Application. Open the Form1 form in the Design view, and then press F4 to open the Properties window. Learn more about files and directories in C. C file handling files and folders in C. Next Recommended Reading. Net Core 6.

Create A. Understanding Thread Starvation in. NET Core Applications. Exploring Numeric Streams In Java. What Is The Metaverse. Microservice Circuit Breaker Pattern. It is used to read from and write to any location within a file. It is used to read primitive data types from a binary stream. It is used to write primitive data types in binary format. IO Assemblies: mscorlib.

Note In members that accept a path as an input string, that path must be well-formed or an exception is raised. In this article. Specifies whether the contents of an existing file are preserved or overwritten, and whether requests to create an existing file cause an exception.

AppendAllText String, String. AppendText String. Copy String, String. Copies an existing file to a new file. Overwriting a file of the same name is not allowed. Copy String, String, Boolean. Overwriting a file of the same name is allowed. Create String. Create String, Int Creates or overwrites a file in the specified path, specifying a buffer size. Create String, Int32, FileOptions. CreateSymbolicLink String, String. CreateText String. Decrypt String.

Delete String. Encrypt String. Encrypts a file so that only the account used to encrypt the file can decrypt it. Exists String. GetAccessControl String. GetAttributes String. GetCreationTime String. Returns the creation date and time of the specified file or directory.

GetCreationTimeUtc String. GetLastAccessTime String. Returns the date and time the specified file or directory was last accessed. GetLastWriteTime String. Returns the date and time the specified file or directory was last written to. Move String, String. Moves a specified file to a new location, providing the option to specify a new file name. Move String, String, Boolean. Open String, FileMode. When we are done within-memory processing, we often need to write the data to disk.

A simple method, File. WriteAllText receives two arguments. It receives the path of the output file, and the exact string contents of the text file. Note The file is created if it does not exist, or replaced with a new file if it does exist no appends ever occur. We could read in a file, append to that in memory, and then write it out completely again. That is slow. Its more efficient to use an append. Argument 1 The first argument to File. AppendAllText is the name of the file we wish to append text to.

Argument 2 The second argument is the string we wish to append to the file—we must add a newline at the end if we want to write a line. Note If the file already exists when the program starts, the file will be appended to. Otherwise, a new file is created. We use File. ReadAllBytes to read an image into memory. Here we read the bytes from a WEBP file into a byte array, and print its length and the first byte.

Benchmark, ReadLine. Suppose we have a text file with many lines—possibly 1 million lines. Version 1 In this version of the code, we read in the file with StreamReader line-by-line. Version 2 Here we read in the file with File. The code is more complex and longer. For files with many lines, it is worth reading in the lines iteratively.

C program that benchmarks reading by lines. We can manipulate directories on the file system with System. The Directory type, and its static methods, is necessary for this.

We can get information about a file from the file system with FileInfo.