1. Create Text File In Visual Basic 2010 Free Download Full Version
2. Vb.net Append To Text File
3. Vb.net Create Text File And Write To It

This lesson is part of an ongoing tutorial. The first part is here:Writing to a text file is similar to reading a text file.

Again we use System.IO.This time, instead of using the StreamReader we use the StreamWriter.The StreamWriter is used to write a stream of text to a file.Add another Button to the form you've been working on. Set the Textproperty of the button to ' Write to File'.

Double click yournew button to open up the coding window. Add the following:Dim FILENAME As String = 'C:UsersOwnerDocumentstest2.txt'If System.IO.File.Exists(FILENAME) = TrueThenDim objWriter As New System.IO.

StreamWriter(FILENAME )objWriter. Write( TextBox1.Text )objWriter.

CloseMessageBox.Show('Text written to file')ElseMessageBox.Show('File Does Not Exist')End IfRun your programme, and then click your new button.Unless you have a file called ' test2.txt', you should seethe message box display: 'File Does Not Exist.' Once again, VB insists that the file must exist before it can actually do somethingwith it. Which is not unreasonable!Stop your programme and change this line:Dim FILENAME As String = 'C:UsersOwnerDocumentstest2.txt'To this:Dim FILENAME As String = 'C:UsersOwnerDocumentstest.txt'In other words, just change the file name back to test.txt. (Hopefully, youhaven't deleted the test.txt file from your hard drive!)Run your programme again. Type something into the textbox, and then click yourbutton. You should see the message box 'Text written to file' appear.But notice that if you open up the text file itself, any text you had previouslywill be gone - it has been overwritten, rather than appended to.

(We'll seehow to append text to a file shortly.)Let's have a look at the code we wrote, though.Once again, we check to see if the File Exists. If it's True that the fileexists, then the first line that gets executed is setting up our variable:Dim objWriter As New System.IO.StreamWriter(FILENAME)It's almost the same as. Only two thingshave changed: we created a new variable name, objWriter, and we're nowusing StreamWriter instead of StreamReader. Everything else isthe same.To write the text to our file, we've used this:objWriter.Write( TextBox1.Text )After the name of our variable (objWriter), we typed a full stop. The dropdown box appeared showing available properties and methods. The ' Write'method was chosen from the list.

In between round brackets, you put what itis you want VB to write to your text file. In our case, this was the text inTextbox1. You can also do this:objWriter.Write( 'Your Text Here' )The above uses direct text surrounded by double quotes.

This is also acceptable:Dim TheText As String = 'Your Text Here'objWriter.Write( TheText )This time, we've put the text inside of a variable. The name of the variableis then typed inside of the round brackets of 'Write'.But you don't have to write the whole text at once. You can write line by line.In which case, select WriteLine from the available properties and methods.Here's an example of how to use WriteLine:Dim FILENAME As String = 'C:UsersOwnerDocumentstest.txt'Dim i As IntegerDim aryText(4) As StringaryText(0) = 'Mary WriteLine'aryText(1) = 'Had'aryText(2) = 'A'aryText(3) = 'Little'aryText(4) = 'One'Dim objWriter As New System.IO. StreamWriter(FILENAME )For i = 0 To 4objWriter.

WriteLine( aryText(i) )NextobjWriter.CloseThe error checking code has been left out here. But notice the new way to writetext to the file:objWriter.WriteLine( aryText(i) )We're looping round and writing the contents of an array. Each line of textfrom the array gets written to our text file. But each line is appended. Thatis, the text file doesn't get erased after each line has been written. All thelines from the array will be written to the text file.

Create Text File In Visual Basic 2010 Free Download Full Version

However, if you wereto run the code a second time then the contents of the file are erased beforethe new WriteLine springs into action. In other words, you'd only getone version of 'Mary WriteLine had a little one' instead of two.In the next part we'll see how to add text to a file that already containstext - called appending to a file.

Working with Text FilesSometimes, you may need to store and retrieve information but not need thepower of a database (not to mention the extra coding, configuration, and supportfiles that go along with it). In these cases, a text file may be just the thingyou need. In this section, you will learn about a simple type of file: a free-form,sequential text file. Sequential means that the file is accessed onebyte after the other in sequence, rather than jumping to a specific location.Free form means that the file has no predefined structure; its structureis entirely up to the programmer. Sequential Text FilesSuppose that you have a form in which the user must choose salespersons froma list, as shown in. Your mission is to load the names of each salesperson into a listbox so that the user can select these names.

You could just put a bunch of AddItemstatements in the FormLoad event. However, doing so would be a poorsolution because you have hard-coded information in the program. Any time thesales force changed, the program would have to be recompiled. A better solutionis to use a text file with the salespersons' names in it.

The program then readsthe names from the text file and populates the list box.The list box is populated with the contents of a text file.To create the file itself, you can use a text editor such as Notepad, and placeeach salesperson's name on a separate line, as shown in.Data stored in sequential text files can be easily edited.This process is simple, and the file can be edited by anyone—even if thatperson doesn't have a database tool. For example, a secretary could maintainthis file on a network server, and the application could copy the most recentversion at startup. Of course, if you are using a database anyway, you mightwant to go ahead and place the names of the sales force in a table. However,a standard text file could still be used for importing into the table.

NOTEThe concept of a shared network file also applies to databases and otherdocuments, which may be useful if everyone on your network uses the samedesktop application programs. Reading from a Sequential Text FileNow that you know how easily you can create a sequential text file, you'reready to write some code to read information from the file. One easy way toprocess a sequential text file is to read it a line at a time. For the salespersonexample described in the preceding section, the steps used for filling up thelist box are very straightforward:.Open the file for input.Read a line from the file, and store it in a variable.Add the contents of the variable to the list box.Repeat steps 2 and 3 for each line in the file.Close the file.The code for filling up the list box, which is discussed in the following sections,is shown in Listing 21.1. Listing 21.1 Filling a List Box from a Text File Sub FillListBoxDim sTemp As StringlstPeople.ClearOpen 'C:DATAPEOPLE.TXT' For Input As #1While Not EOF(1)Line Input #1, sTempLstPeople.AddItem sTempWendClose #1End SubNow, examine the code a little more closely. First, before you read or writeinformation, you must open the file with the Open statement. The Openstatement associates the actual filename (PEOPLE.TXT in the example) with afile number.

A file number is an integer value used to identify the fileto other Visual Basic code: Open 'C:DATAPEOPLE.TXT' For Input As #1. NOTEIn the preceding example, 1 is the file number. However, if you open andclose multiple files throughout your program, using this number might notbe a good idea. In that case, you should use the FreeFile function,which returns the next available file number, as in the following example:Dim nFile As IntegernFile = FreeFileOpen 'C:MYFILE.TXT' for Input As #nFileAfter you finish using a file, you should close it with the Close statement(refer to Listing 21.1). This way, you can free up the file number for use withother files.In addition to providing the filename and number association, the Openstatement tells Visual Basic how you intend to use the specified file.

(Manydifferent options are available with the Open statement, as discussedin the Help file.). TIPBefore you open a file for input, use the Dir$ function to see whetherit actually exists.The keyword Input indicates that the file will be opened for SequentialInput, which means that you can only move forward through the file in sequence.The act of reading information from the file automatically moves an internalfile pointer forward for the next read. The code in Listing 21.1 uses a LineInput statement in a While loop to read information.

Vb.net Append To Text File

The first LineInput statement reads the first line, the second Line Input readsthe second line, and so on. A line in a file is delimited by an end of linemarker, which in Windows is the carriage return character followed by the linefeed character. The syntax of the Line Input statement is Line Input #filenumber,variablenamewhere filenumber is an open file number and variablename is astring or variant variable. If you try to read more lines of text than are inthe file, an error occurs. Therefore, you should use the EOF (end-of-file)function to check whether you have reached the end of file before attemptingto read again.After you open the file, you can choose from several methods of reading informationfrom it. In the example, each name is the only piece of information on eachline, so no further processing on the string variable is necessary.

However,sometimes you may want to read less than a whole line or store more than onepiece of information on a single line. In these cases, you can use the Input# statement or the Input function.The Input # statement is designed to read information stored in a delimitedfashion. For example, the following line of a text file contains three distinctpieces of information: a string, a number, and a date. Commas, quotation marks,and the # symbol are used to delimit the information.

'Test',100,#1998-01-01#The following line of code correctly reads each item from the file into theappropriate variables: Input #1, stringvar, intvar, datevarRemember that the Input # statement looks for those delimiters, so makesure that your Input # statements match the format of the file.Another method of reading information is the Input function. The Inputfunction allows you to specify the number of characters to read from the file,as in the following example: 'Reads five Character from file number 1s = Input(5,#1)Now, compare how each of the methods just discussed would process the sameline in a file: 'Assume our file has the following line repeated in it:'This is a test string.' Dim s As StringLine Input #1, s's contains the entire string including quotesInput #1, s's contains the string without quotess = Input(5,#1)'s Contains the first 5 characters ('This) Writing to a Sequential Text FileOne good use of a sequential text file is a log file.

Vb.net Create Text File And Write To It

For example, I have ascheduler application that runs programs and database updates. I rarely workat the machine on which the scheduler application is running, but I can connectover the network and view the log file to see whether the updates have completed. TIPYou can create batch files, FTP scripts, and many other simple file formatson-the-fly by using sequential text files.Listing 21.2 is a subroutine called LogPrint, which can be added toyour program to log error messages. It writes the error message and date toa sequential text file. Listing 21.2 Using a Sequential Output File to Build an ApplicationLog Sub LogPrint(sMessage As String)Dim nFile As IntegernFile = FreeFileOpen App.Path & 'ErrorLog.TXT' for Append Shared as #nFilePrint #nFile,format$(Now,'mm-dd hh:mm:ss') & ' – ' & sMessageClose #nFileEnd SubWith a few lines of code, you can add a log file to your application.The function can be called from an error routine or to inform you of a programevent: LogPrint 'The database was successfully opened.' The output of the log file can be viewed with a text editor, as shown in.Recall from Listing 21.1 (in the preceding section) that you opened the filein Input mode by using the keyword Input. To write data, you open thefile for sequential output.

However, instead of using the keyword Output,you use Append. Compare the following two lines of code, each of whichopens a file for output: 'Append mode – adds to an existing file or creates a new oneOpen 'ErrorLog.TXT' for Append as #1'Output Mode – always creates a new file, erases any existing informationOpen 'ErrorLog.TXT' for Output as #1Append mode means that data written to the file is added to the end of anyexisting data. This is perfect for the log file application because you wantto keep adding to the log file.

Opening a file for Output means thatany existing data will be erased. In either case, the Open statementautomatically creates the file if it does not exist. After a file has been openedfor Output, you can use a couple of different statements to write informationto it.