How to: Read From a Text File (C# Programming Guide)
This example reads the contents of a text file by using the static methods on the System.IO.File class ReadAllText and ReadAllLines.
Note
The files that are used in this example were created in the topic How to: Write to a Text File (C# Programming Guide).
Example
class ReadFromFile
{
static void Main()
{
// The files used here were created in the code example
// in How to: Write to a Text File. You can of course substitute
// other files of your own.
// Example #1
// Read the file as one string.
string text = System.IO.File.ReadAllText(@"C:\Users\Public\TestFolder\WriteText.txt");
// Display the file contents to the console.
System.Console.WriteLine("Contents of writeText.txt = {0}", text);
// Example #2
// Read the file lines into a string array.
string[] lines = System.IO.File.ReadAllLines(@"C:\Users\Public\TestFolder\WriteLines2.txt");
System.Console.WriteLine("Contents of writeLines2.txt =:");
foreach (string line in lines)
{
Console.WriteLine("\t" + line);
}
// Keep the console window open in debug mode.
Console.WriteLine("Press any key to exit.");
System.Console.ReadKey();
}
}
Compiling the Code
Copy the code and paste it into a console application.
Replace "c:\testdir" with the actual folder name.
Robust Programming
The following conditions may cause an exception:
- The file may not exist.
Security
Do not rely on the name of a file to determine the contents of a file. For example, the file myFile.cs may not be a C# source file.