The My.Computer.FileSystem object provides the ReadAllBytes method for reading from binary files.
To read from a binary file
Use the ReadAllBytes method, which returns the contents of a file as a byte array. This example reads from the file C:/Documents and Settings/selfportrait.jpg.
Dim bytes = My.Computer.FileSystem.ReadAllBytes( "C:/Documents and Settings/selfportrait.jpg")PictureBox1.Image = Image.FromStream(New IO.MemoryStream(bytes))
For large binary files, you can use the Read method of the FileStream object to read from the file only a specified amount at a time. You can then limit how much of the file is loaded into memory for each read operation. The following code example copies a file and allows the caller to specify how much of the file is read into memory per read operation.
' This method does not trap for exceptions. If an exception is ' encountered opening the file to be copied or writing to the ' destination location, then the exception will be thrown to ' the requestor.Public Sub CopyBinaryFile(ByVal path As String, ByVal copyPath As String, ByVal bufferSize As Integer, ByVal overwrite As Boolean) Dim inputFile = IO.File.Open(path, IO.FileMode.Open) If overwrite AndAlso My.Computer.FileSystem.FileExists(copyPath) Then My.Computer.FileSystem.DeleteFile(copyPath) End If ' Adjust array length for VB array declaration. Dim bytes = New Byte(bufferSize - 1) {} While inputFile.Read(bytes, 0, bufferSize) > 0 My.Computer.FileSystem.WriteAllBytes(copyPath, bytes, True) End While inputFile.Close()End Sub
Robust Programming
The following conditions may cause an exception to be thrown:
The path is not valid for one of the following reasons: it is a zero-length string, it contains only white space, it contains invalid characters, or it is a device path (ArgumentException).
A file or directory name in the path contains a colon (:) or is in an invalid format (NotSupportedException).
There is not enough memory to write the string to buffer (OutOfMemoryException).
The user lacks necessary permissions to view the path (SecurityException).
Do not make decisions about the contents of the file based on the name of the file. For example, the file Form1.vb may not be a Visual Basic source file.
Verify all inputs before using the data in your application. The contents of the file may not be what is expected, and methods to read from the file may fail.
Use the ReadAllBytes method, which returns the contents of a file as a byte array. This example reads from the file C:/Documents and Settings/selfportrait. ...
For large binary files, you can use the Read method of the FileStream object to read from the file only a specified amount at a time.
The steps involved in reading data from a binary file are the same as for reading data from a text file: Create an input stream and open the file, read the data, close the file. The main difference lies in the way you check for the end-of-file marker in a binary file.
To search for specific non-ASCII strings or patterns in binary files, we can use the grep command with the -a flag. This will instruct grep to handle the binary file as a text file, even if it includes non-ASCII characters.
Use the ReadAllText method of the My.Computer.FileSystem object to read the contents of a text file into a string, supplying the path. The following example reads the contents of test.
When working with binary files you'll typically use a library (either a built-in Python library or a third-party library) that knows how to process the specific type of file you're working with . That library will do the work of decoding the bytes from your file into something that's easier to work with.
Remember that in binary 1 is "on: and 0 is "off." Choose the binary number that you want to decode.Give each number a value, starting from the extreme right. For example, using the number 1001001, 1=1, +0=2, +0=4, +1=8, +0=16, +0=32, +1=64.
In a sense, all files are "binary" in that they are just a collection of bytes stored in an operating system construct called a file. However, when we talk about binary files, we are really referring to the way VB opens and processes the file.
The BinaryReader class is used to read binary data from a file. A BinaryReader object is created by passing a FileStream object to its constructor. The following table describes commonly used methods of the BinaryReader class.
The READ_BINARY function reads the contents of a binary file using a passed template or basic command line keywords. Data is read from the given filename or from the current file position in the open file pointed to by FileUnit. If no template is provided, keywords can be used to read a single IDL array of data.
Binary files are not human-readable because the bytes they contain translate to characters and symbols that have many other non-printable characters. The text editor shows any binary file as characters such as Ø and ð. Binary files must be read by programs to be useable.
In a sense, all files are "binary" in that they are just a collection of bytes stored in an operating system construct called a file. However, when we talk about binary files, we are really referring to the way VB opens and processes the file.
The BinaryReader class is used to read binary data from a file. A BinaryReader object is created by passing a FileStream object to its constructor. The following table shows some of the commonly used methods of the BinaryReader class.
Here, we will use the ReadAllBytes() method of the File class to read all byte values from the specified file. Program/Source Code: The source code to read all bytes from a file is given below. The given program is compiled and executed successfully.
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