How to open and read a text file in vb.net

Here we set it to blank and hopefully force the user to type in a file name. Now that we have the open file dialog window configured, we show it using the showdialog method. This function shows the dialog in modal mode which forces the user to then choose a file and either hit ok, cancel or close the window. In either case we check to make sure they chose ok by comparing it against the OK dialog result enumeration value. Once they have chosen ok, we check the filename to make sure it exists.

This is a tad bit different than something like a save dialog where the filename may be new and not exist yet. After validating the result of the dialog, that they pressed ok, and that a filename was chosen we attempt to open the file by first creating a StreamReader. The best way to think of a stream is like a river of data.

You can open up a dam, let the data flow and scoop out data using reading methods. A stream reader is one of those such mechanisms. In order to setup the streamreader, we have to let it know that we are reading a file stream, so we use the filestream object to open the file in read mode versus write mode.

If this opening of the stream fails, like the file is not found, it would trip off our error catching and print a message saying that the file is not found. But if it succeeds, we then go to the process of reading the file. We chose to use a while loop which peeks at the stream to see if there is data to be read.

You do the opening like this:. Now that objReader is an object variable, it has its own properties and methods available for use in the same way that the textbox has a Text property. This will read the whole of your text, right to the end. We're then popping this in a textbox. The last line closes the StreamReader we set up.

Unless you already have a file called test. So we were trying to read a text file that doesn't exist. No more reading these lessons online - get the eBook here! You can, though, test to see if the file exists. If it does, you can open it; if not, you can display an error message. Amend your code to this the new lines are in bold :. Dim objReader As New System. ReadToEnd objReader. We've now wrapped up our code in an If Statement. ReadLine End Using ' Write the line we read from "file.

ReadLines "MyTextFile. Dayan Dayan 7, 11 11 gold badges 41 41 silver badges 73 73 bronze badges. I use IO. ReadAllText "BikeDefault. CoolCoder CoolCoder 23 5 5 bronze badges. Sign up or log in Sign up using Google. Sign up using Facebook. Sign up using Email and Password. Post as a guest Name. Email Required, but never shown. The Overflow Blog.

FileSystem object allows you to read from a text file. If you are reading from a file with extended characters, you will need to specify the file encoding. FileSystem object. You can use the ReadLine method of the StreamReader object to read a file one line at a time.

Use the ReadAllText method of the My. FileSystem object to read the contents of a text file into a string, supplying the path.

The following example reads the contents of test. FileSystem object to read the contents of a text file into a string, supplying the path and file encoding type.