File i o in vb6

Sign in Join Now. New Post. Using these commands along with the string functions can provide a very valuable set of tools without the need to add any library references or late binding object to use the file scripting object.

Each of the statements are hyperlinked to the Microsoft Programer's Reference site for more detail FreeFile allows you to find the very next, lowest, available pointer. However, if you close 1, then call FreeFile, it will return 1 and files referenced with 2 and 3 will remain open!

For more information about using the Random mode How to Work with Random Access Files The lock modes are: Shared, Lock Read, Lock Write, and Lock Read Write Reclength, I rarely use and has to do with either the bytes or characters buffered depending on how the mode used to open the file; however, say the data is in the first characters of a character file, why open the entire thing.

You also need to close a file between modes, so to go from input to output or random and lock types you need to first close the file then re-open the file with the correct settings. This is probably of most use when you have a record of fixed width or length i. Therefore, if you need delimitation in the file, you need to provide it in the string format. Sending a print to the file without anything inserts an empty, zero length, string blank line ; however, If there is a Null valued variable, it will insert a Null character in the line and then return.

Expand Select Wrap Line Numbers. Line Input 1, InputData ' Read line of data. Basics of. Is this page helpful? Please rate your experience Yes No. Any additional feedback? Note Other topics in this section use the My. Submit and view feedback for This product This page. View all page feedback. In this article. How to: Read Text from a File.

How to: Write Text to a File. How to: Read Characters from a String. How to: Write Characters to a String. Encrypting Data. Decrypting Data. How to: Open and Append to a Log File. How to: Obtain Stores for Isolated Storage.

The GetFiles method then retrieves a collection of strings, one for each file in the directory. The GetFiles method accepts a search pattern argument to retrieve files that match a particular pattern. In this example, only files that have the extension. The strings that are returned by the GetFiles method are then added to the ListBox.

Run the application. Click the Browse button. In the Browse For Folder dialog box, browse to a folder that contains. Create a Click event handler for examineButton by double-clicking the control on the form. The code verifies that an item is selected in the ListBox.

It then obtains the file path entry from the ListBox. The FileExists method is used to check whether the file still exists. The file path is sent as an argument to the GetTextForOutput method, which is added in the next step. This method returns a string that contains file information.

The file information appears in a MessageBox. The code uses the GetFileInfo method to obtain file parameters. The file parameters are added to a StringBuilder.

Text files can be used to store fairly large blocks of text for example, a short story, a letter, or a poem. We are more interested here, however, in text files that can store records. A record is a single line in a file that consists of one or more fields. In text-based data files, the fields in a record are usually comma-delimited i. A typical file processing operation opens a file, reads the records into memory and processes them one at a time.

The results of this processing are normally output to the screen. Once all of the required records have been read from the file, the file is closed. If records have been modified by a program, the amended records are usually either written back to the same file, or to a another file. Writing data to a file is a separate operation in which the file must be re-opened, or a new file created. If amended records are written back to the same file, the original version of each record will be replaced overwritten by the new version.

If new data is being added to a file, the records will be added appended to the end of the file, and the existing data will be preserved. The act of opening a file and reading the records it contains into memory can be described as pre-processing , because this action prepares the records for processing. When records are read from a file, they are accessed sequentially one after the other , in whatever order they happen to be stored in within the file.

Sequential input from a file is called a data stream. We are now going to create a simple program to read data from a text file and display the data in a text box. Download the file country.

Dim srdFile As IO. StreamReader "country. ReadLine rtbOutput. The first line of code declares a variable of type IO. This is one of the standard classes defined within VB. Net's System. IO namespace, and as the name suggests it includes methods for reading data from files. The second line of code declares a string variable called strLine which will hold each line of text read from the file. In the next line of code, the command rtbOutput. The fourth line of code uses the New keyword to allocate memory to the variable srdFile it essentially creates a new instance of a StreamReader object , associates it with the file country.

Providing the country. If you were to move the file to a different folder, you would need to add the drive and path information in order to enable the program to find it. The Do. Until loop iterates through the instructions contained within it until the exit condition is met.