File.OpenText() Method in C# with Examples
File.OpenText(String) is an inbuilt File class method which is used to open an existing UTF-8 encoded text file for reading.
Syntax:
public static System.IO.StreamReader OpenText (string path);
Parameter: This function accepts a parameter which is illustrated below:
- path: This is the specified text file which is going to be opened for reading.
Exceptions:
- UnauthorizedAccessException: The caller does not have the required permission.
- ArgumentException: The path is a zero-length string, contains only white space, or one or more invalid characters as defined by InvalidPathChars.
- ArgumentNullException: The path is null.
- PathTooLongException: The specified path, file name, or both exceed the system-defined maximum length.
- DirectoryNotFoundException: The specified path is invalid.
- FileNotFoundException: The file specified in the path was not found.
- NotSupportedException: The path is in an invalid format.
Return Value: Returns a StreamReader on the specified path.
Below are the programs to illustrate the File.OpenText(String) method.
Program 1: Before running the below code, a text file file.txt is created with some contents shown below-
Below code open the text file file.txt for reading.
C#
using System;
using System.IO;
class Test {
public static void Main()
{
string path = @"file.txt" ;
using (StreamReader sr = File.OpenText(path))
{
string s = "" ;
while ((s = sr.ReadLine()) != null ) {
Console.WriteLine(s);
}
}
}
}
|
Executing:
GeeksforGeeks
Program 2: Initially, a file file.txt is created with some contents shown below-
This below code will overwrite the file contents with other specified contents then final contents will be printed.
C#
using System;
using System.IO;
class Test {
public static void Main()
{
string path = @"file.txt" ;
if (File.Exists(path)) {
using (StreamWriter sw = File.CreateText(path))
{
sw.WriteLine( "GFG is a CS portal." );
}
}
using (StreamReader sr = File.OpenText(path))
{
string s = "" ;
while ((s = sr.ReadLine()) != null ) {
Console.WriteLine(s);
}
}
}
}
|
Executing:
GFG is a CS portal.
Last Updated :
10 Nov, 2021
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