Reading a flat file in vb.net

To read from a file, your assembly requires a privilege level granted by the FileIOPermission class. If you are running in a partial-trust context, the code might throw an exception due to insufficient privileges. For more information, see Code Access Security Basics. The user also needs access to the file. Skip to main content. In which case, instead of using the ReadToEnd method, as we did in the previous section , you can use the ReadLine method:.

The ReadLine method, as its name suggests, reads text one line at a time. In order to do this, though, you need to use a loop. You can then loop round each line and read it into a variable. Here's a coding example:.

The Peek method takes a peek at the incoming text characters. NET framework provides several classes for working with text files, binary files, directories, and byte streams.

I will look specifically at working with text files using classes from the System. Basic methods Before we jump into working with text files, we need to create a new file or open an existing one.

That requires the System. File class. This class contains methods for many common file operations, including copying, deleting, file attribute manipulation, and file existence. For our text file work, we will use the CreateText and OpenText methods. StreamWriter object. With the StreamWriter object, you can then write to the file. The following code demonstrates how to create a text file: Dim oFile as System. File Dim oWrite as System. StreamReader object. With the StreamReader object, you can then read the file.

File Dim oRead as System. StreamWriter class for writing to the text file are Write and WriteLine. The difference between these methods is that the WriteLine method appends a newline character at the end of the line while the Write method does not. Both of these methods are overloaded to write various data types and to write formatted text to the file. This browser is no longer supported. Download Microsoft Edge More info. Contents Exit focus mode. Is this page helpful? Please rate your experience Yes No.

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