C, the description of the FileInfo class and the File class is correct

The file class is used for typical operations such as copying, moving, renaming, creating, opening, deleting, and appending to files. You can also use the file class to get and set file properties or datetime information about file creation, access, and write operations.

Many file methods return other IO types when you create or open a file. You can use these other types to further process the file.

Since all file methods are static, it may be more efficient to use the file method than the corresponding fileinfo instance method if you only want to perform one operation. All file methods require the path of the file you are currently working on.

The static method of the file class performs security checks on all methods. If you plan to reuse an object multiple times, consider using the appropriate instance method of fileinfo instead, as security checks are not always required.

Any public static members of the file class are thread-safe, but not all instance members are guaranteed to be thread-safe.

The fileinfo class is used for typical operations such as copying, moving, renaming, creating, opening, deleting, and appending to files. If you plan to reuse an object multiple times, consider using the instance method of fileinfo instead of the corresponding static method of the file class, as security checks are not always required.

Any public static members of the fileinfo class are also thread-safe, but not all instance members are guaranteed to be thread-safe.

So from the above analysis, the correct answer is d

Is this multiple choice? A and C are clearly opposites.

Answer]: The file operation classes provided in the namespace are file and fileinfo, the functions of these two classes are basically the same, except that file is a static class, in which all methods are static, which can be called directly through the class name and do not need to be instantiated. FileInfo, on the other hand, is a normal class, and methods in it can only be called after the object has been instantiated.

The file class is a static class, which operates on the entire file system, and the methods are static syntax. If you only perform a small number of operations on files, such as determining whether a file exists or performing operations on a large number of files, it is recommended to use the file class to avoid the overhead of frequently creating and releasing objects.

The fileinfo class is an instance class, which operates on a file, and most of the methods are instance methods, and its operation may be the corresponding static method in the file that is called. If you are performing a large number of operations on a file, it is recommended to use the fileinfo class.

So why do you still use fileinfo sometimes? This is because every time a method is called through the file class, it takes a certain amount of CPU processing time to perform a secure unchained check, even when the same file is accessed repeatedly using methods of different file classes. The fileinfo class, on the other hand, performs a security check only once when a fileinfo object is created.

In many cases, there is no need to generate a fileinfo object for ease of operation.

For example: copy a file to another place:

newfilepath).

If you use fileinfo

may need: fileinof fi = new fileinfo();

We can use the following rules to determine:

1. If the application performs several operations on the file, it is better for Liang Ju to use the fileinfo class, because when the object is created, the correct file has been referenced, while the static class has to find the file every time, which will take more time.

2. If a single method call is made, it is recommended to use the file class instead of instantiating the object.