To manage files we have File class and FileInfo class.
File
The File Class provides static methods for the creation,
copying, deletion, moving and opening of files. It also aids in the creation
of FileStream objects. The methods of the File class have been explained in
the sections that follow.
AppendText Method
AppendText Method appends text in an existing file as
specified in the path. This method returns a streamwriter object that is used
to append contents in the file.
Listing 32
StreamWriter sw=File.AppendText(@"E:\test.txt");
sw.WriteLine("This is line no 4" );
sw.WriteLine("This is line no 5");
sw.WriteLine("This is line no 6");
sw.Close();Copy Method
Copy Method copies an existing file to a new file.
Listing 33
File.Copy(Server.MapPath("TestDirectoryFile1.doc"),Server.MapPath("TestDirectoryFile2.doc"));Create Method
Create Method creates a file in the specified path.
Listing 34
File.Create(Server.MapPath("TestFile.doc"));CreateText Method
CreateText Method opens or creates a new file as specified
in the path. This method returns a streamwriter object that is used to write
content in the file. Contents of the existing file are overwritten provided
the file is not in read only mode.
Listing 35
StreamWriter sw=File.CreateText(@"E:\test.txt");
sw.WriteLine("This is line no 1" );
sw.WriteLine("This is line no 2");
sw.WriteLine("This is line no 3");
sw.Close();Delete Method
Delete Method deletes the specified file.
Listing 36
File.Delete(Server.MapPath("TestFile.doc"));Exists Method
Exists Method determines whether the specified file exists.
Listing 37
if(File.Exists(Server.MapPath("TestDirectoryFile1.doc")))
{
Response.Write("File Exist");
}
else
{
Response.Write("File Does Not Exist");
} GetCreationTime Method
GetCreationTime Method returns the creation date and time of
the file specified in the path.
Listing 38
string str=File.GetCreationTime(@"E:\test.txt").ToString();
GetLastAccessTime Method
GetLastAccessTime Method returns the last access date and
time of the specified file in the path.
Listing 39
string str=File.GetLastAccessTime(@"E:\test.txt").ToString();
GetLastWriteTime Method
GetLastWriteTime Method returns the last written date and
time in the specified file in the path.
Listing 40
string str=File.GetLastWriteTime(@"E:\test.txt").ToString();
Move Method
Move Method moves a specified file to a new location.
Listing 41
File.Move(Server.MapPath("TestDirectoryFile1.doc"),Server.MapPath("TestDirectoryFile2.doc"));Open Method
Open Method opens a FileStream on the specified path with
read or write access
The syntax is:
File.Open(Server.MapPath("TestDirectoryFile.doc"), FileMode, FileAccess, FileShare);Once a file is opened and we have FileStream object, we can
create a reader or writer object to work with the file’s contents.
The following code listing shows how to write a few lines of
text to a file using the StreamWriter Class.
Listing 42
FileStream fs;
StreamWriter sw;
fs=File.Open(@"E:\test.txt",FileMode.Append,FileAccess.Write,FileShare.Write);
sw=new StreamWriter(fs);
sw.WriteLine("Write 1");
sw.WriteLine("Write 2");
sw.WriteLine("Write 3");
sw.Close();FileInfo
The FileInfo class provides instance methods for the
creation, copying, deletion, moving and opening of files. It also provides
members to create FileStream objects.
AppendText Method
AppendText Method appends text in an existing file using
StreamWriter object returned by this method.
Listing 43
FileInfo fi=new FileInfo(@"E:\test.txt");
StreamWriter sw=fi.AppendText();
sw.WriteLine("This is a new line");
sw.Close();CopyTo Method
CopyTo Method copies an existing file to a new file.
Listing XXXXIV
FileInfo fi=new FileInfo(Server.MapPath("TestDirectoryFile.doc"));
fi.CopyTo(Server.MapPath("NewTestDirectoryFile.doc"));Create Method
Create Method creates a file.
Listing 44
FileInfo fi=new FileInfo(Server.MapPath("TestDirectoryFile.doc"));
fi.Create();CreateText Method
CreateText Method writes a new text file.
Listing 45
FileInfo fi=new FileInfo(Server.MapPath("TestDirectoryFile.doc"));
fi.CreateText();Delete Method
Delete Method deletes a file.
Listing 46
FileInfo fi=new FileInfo(Server.MapPath("TestDirectoryFile.doc"));
fi.Delete();MoveTo Method
Move Method renames or moves an existing file.
Listing 47
FileInfo fi=new FileInfo(Server.MapPath("TestDirectoryFile.doc"));
fi.MoveTo(Server.MapPath("NewTestDirectoryFile.doc"));Open Method
Open Method opens a file with various read or write and
sharing privileges. Once a file is opened and we have FileStream object, we
can create a reader or writer object to work with the file’s contents.
Listing 48
FileStream fs;
StreamWriter sw;
FileInfo fis=new FileInfo(@"E:\TestDirectoryFile\test.txt");
fs=fis.Open(FileMode.Append,FileAccess.Write,FileShare.Write);
sw=new StreamWriter(fs);
sw.WriteLine("Write 1");
sw.WriteLine("Write 2");
sw.WriteLine("Write 3");
sw.Close(); 
