.NET Files Operations: Routine Operations on Files

	.NET Files Operations: Routine Operations on Files

Opening a File

As opposed to creating a file, probably the second most regular operation performed on a file consists of opening it to read or explore its contents. To support opening a file, the FileInfo class is equipped with the Open() method that is overloaded with three versions.

If you have a text-based file and want to directly read from it, you can use the StreamReader class that is equipped with the Read() and the ReadLine() methods. As done for the StreamWriter class, after using a StreamReader object, make sure you close it.

Deleting a File

If you have an existing file you don't need anymore, you can delete it. This operation can be performed by calling the FileInfo::Delete() method. Its syntax is:

public:
    virtual void Delete() override;

Here is an example:

FileInfo ^ fleMembers = gcnew FileInfo(L"First.txt");
fleMembers->Delete();

Copying a File

You can make a copy of a file from one directory to another. To do this, you can call the FileInfo::CopyTo() method that is overloaded with two versions. The first version has the following syntax:

public:
    FileInfo ^ CopyTo(String ^ destFileName);

When calling this method, specify the path or directory that will be the destination of the copied file. Here is an example:

FileInfo ^ fleMembers = gcnew FileInfo(L"Reality.txt");
String ^ strMyDocuments =
    Environment.GetFolderPath(Environment::SpecialFolder::Personal);
fleMembers->CopyTo(String.Concat(strMyDocuments, "\\Federal.txt"));

In this example, a file named Reality.txt in the directory of the project would be retrieved and its content would be applied to a new file named Federal.txt created in the My Documents folder of the current user.

When calling the first version of the FileInfo::CopyTo() method, if the file exists already, the operation would not continue and you would simply receive a message box. If you insist, you can overwrite the target file. To do this, you can use the second version of this method. Its syntax is:

public:
    FileInfo ^ CopyTo(String ^destFileName, bool overwrite);

The first argument is the same as that of the first version of the method. The second argument specifies what action to take if the file exists already in the target directory. If you want to overwrite it, pass the argument as true; otherwise, pass it as false.

Moving a File

If you copy a file from one directory to another, you would have two copies of the same file or the same contents in two files. Instead of copying, if you want, you can simply move the file from one directory to another. This operation can be performed by calling the FileInfo::MoveTo() method. Its syntax is:

public:
    void MoveTo(String ^destFileName);

The argument to this method is the same as that of the CopyTo() method. After executing this method, the FileInfo object would be moved to the destFileName path.

Here is an example:

FileInfo ^ fleMembers = gcnew FileInfo(L"pop.txt");
String ^ strMyDocuments = Environment::GetFolderPath(Environment::SpecialFolder::Personal);
fleMembers->CopyTo(String::Concat(strMyDocuments, "\\pop.txt"));


Home	Copyright © 2007 FunctionX, Inc.	Next