There are additional conditions that may cause exceptions when working with the file system, it is best to program defensively. PathTooLongException: The path name may be too long.InvalidOperationException: The file exists and is read-only.The following conditions may cause an exception: Awaits a call to StreamWriter.WriteLineAsync(String), which writes the string to the file as an appended line.Instantiates a StreamWriter with a file path of WriteLines2.txt as a using declaration, passing in true to append.Using StreamWriter file = new("WriteLines2.txt", append: true) Īwait file.WriteLineAsync("Fourth line") Conditionally awaits a call to StreamWriter.WriteLineAsync(String), which writes the line to the file when the line doesn't contain "Second".Īppend text to an existing file class StreamWriterTwo.Instantiates a StreamWriter with a file path of WriteLines2.txt as a using declaration.Instantiates a string array with three values.Using StreamWriter file = new("WriteLines2.txt") Called by GpsPrune to receive data from a GPS or to send data back. Can be run either from the command line or from a GUI.
Write selected strings from an array to a file class StreamWriterOne (free) Specialises in conversion of coordinate data between file formats and data formats, including communicating with countless GPS receivers for download and upload. If the file already exists, it is overwritten. Asynchronously creates a file name WriteText.txt.Instantiates a string given the assigned string literal.Īwaits a call to File.WriteAllTextAsync which: " Īwait File.WriteAllTextAsync("WriteText.txt", text) "a class defines the data and behavior of the data type. "A class is the most powerful data type in C#. Write one string to a file class WriteAllText Closes the file, automatically flushing and disposing as needed.
Instantiates a string array with three values.Īwaits a call to File.WriteAllLinesAsync which: "First line", "Second line", "Third line"Īwait File.WriteAllLinesAsync("WriteLines.txt", lines) Write a collection of strings to a file class WriteAllLines If you want to format text written to a file, use the Format method or C# string interpolation feature. These examples all write string literals to files.
The final example shows how to append text to an existing file. In the first three examples, you overwrite all existing content in the file. The third example shows how to add text to a file when you have to process each line individually as you write to the file. The first two examples use static convenience methods on the System.IO.File class to write each element of any IEnumerable and a string to a text file. In this article, there are several examples showing various ways to write text to a file.