Methods file

To use the File class, create an object of the class, and specify the filename or directory name: Example import java. The File class has many useful methods for creating and getting information about files. For example:. We just launched W3Schools videos. Where necessary, use null , undefined or some other placeholder value for properties where the desired value isn't yet available. It is possible to add a new property directly to the component instance without including it in data.

You should avoid using names for top-level data properties that start with either of these characters. To add methods to a component instance we use the methods option. This should be an object containing the desired methods:. Vue automatically binds the this value for methods so that it always refers to the component instance. Use the File class for typical operations such as copying, moving, renaming, creating, opening, deleting, and appending to a single file at a time. You can also use the File class to get and set file attributes or DateTime information related to the creation, access, and writing of a file.

If you want to perform operations on multiple files, see Directory. GetFiles or DirectoryInfo. You can use these other types to further manipulate a file. Because all File methods are static, it might be more efficient to use a File method rather than a corresponding FileInfo instance method if you want to perform only one action. All File methods require the path to the file that you are manipulating. The static methods of the File class perform security checks on all methods. If you are going to reuse an object several times, consider using the corresponding instance method of FileInfo instead, because the security check will not always be necessary.

The following table describes the enumerations that are used to customize the behavior of various File methods. In members that accept a path as an input string, that path must be well-formed or an exception is raised. For example, if a path is fully qualified but begins with a space, the path is not trimmed in methods of the class. Therefore, the path is malformed and an exception is raised. Similarly, a path or a combination of paths cannot be fully qualified twice.

Ensure that your paths are well-formed when using methods that accept a path string. In members that accept a path, the path can refer to a file or just a directory. The specified path can also refer to a relative path or a Universal Naming Convention UNC path for a server and share name. For example, all the following are acceptable paths:.

Appends lines to a file, and then closes the file. If the specified file does not exist, this method creates a file, writes the specified lines to the file, and then closes the file. Appends lines to a file by using a specified encoding, and then closes the file. Asynchronously appends lines to a file, and then closes the file.

Asynchronously appends lines to a file by using a specified encoding, and then closes the file. Opens a file, appends the specified string to the file, and then closes the file. If the file does not exist, this method creates a file, writes the specified string to the file, then closes the file. Appends the specified string to the file using the specified encoding, creating the file if it does not already exist.

Asynchronously opens a file or creates a file if it does not already exist, appends the specified string to the file, and then closes the file. Asynchronously opens a file or creates the file if it does not already exist, appends the specified string to the file using the specified encoding, and then closes the file.

Creates a StreamWriter that appends UTF-8 encoded text to an existing file, or to a new file if the specified file does not exist. Creates or overwrites a file in the specified path, specifying a buffer size and options that describe how to create or overwrite the file. Creates or overwrites a file in the specified path, specifying a buffer size, options that describe how to create or overwrite the file, and a value that determines the access control and audit security for the file.

Creates a file symbolic link identified by path that points to pathToTarget. Creates or opens a file for writing UTF-8 encoded text. If the file already exists, its contents are overwritten. Decrypts a file that was encrypted by the current account using the Encrypt String method.

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