UnmanagedMemoryStream::WriteByte Method (Byte)
Writes a byte to the current position in the file stream.
Assembly: mscorlib (in mscorlib.dll)
Parameters
- value
-
Type:
System::Byte
A byte value written to the stream.
| Exception | Condition |
|---|---|
| ObjectDisposedException | The stream is closed. |
| NotSupportedException | The underlying memory does not support writing. - or - An attempt is made to write to the stream and the CanWrite property is false. - or - The current position is at the end of the capacity of the stream. |
| IOException | The supplied value causes the stream exceed its maximum capacity. |
The following code example demonstrates how to read from and write to unmanaged memory using the UnmanagedMemoryStream class. A block of unmanaged memory is allocated and de-allocated using the Marshal class. In this example, an UnmanagedMemoryStream object is passed to a method which checks the CanWrite property before attempting to write the data to the stream.
// Note: You must compile this sample using the unsafe flag. // From the command line, type the following: csc sample.cs /unsafe using System; using System.IO; using System.Runtime.InteropServices; using System.Text; unsafe class Program { static void Main() { // Create some data to write. byte[] text = UnicodeEncoding.Unicode.GetBytes("Data to write."); // Allocate a block of unmanaged memory. IntPtr memIntPtr = Marshal.AllocHGlobal(text.Length); // Get a byte pointer from the unmanaged memory block. byte* memBytePtr = (byte*)memIntPtr.ToPointer(); UnmanagedMemoryStream writeStream = new UnmanagedMemoryStream( memBytePtr, text.Length, text.Length, FileAccess.Write); // Write the data. WriteToStream(writeStream, text); // Close the stream. writeStream.Close(); // Create another UnmanagedMemoryStream for reading. UnmanagedMemoryStream readStream = new UnmanagedMemoryStream(memBytePtr, text.Length); // Display the contents of the stream to the console. PrintStream(readStream); // Close the reading stream. readStream.Close(); // Free up the unmanaged memory. Marshal.FreeHGlobal(memIntPtr); } public static void WriteToStream(UnmanagedMemoryStream writeStream, byte[] text) { // Verify that the stream is writable: // By default, UnmanagedMemoryStream objects do not have write access, // write access must be set explicitly. if (writeStream.CanWrite) { // Write the data, byte by byte for (int i = 0; i < writeStream.Length; i++) { writeStream.WriteByte(text[i]); } } } public static void PrintStream(UnmanagedMemoryStream readStream) { byte[] text = new byte[readStream.Length]; // Verify that the stream is writable: // By default, UnmanagedMemoryStream objects do not have write access, // write access must be set explicitly. if (readStream.CanRead) { // Write the data, byte by byte for (int i = 0; i < readStream.Length; i++) { text[i] = (byte)readStream.ReadByte(); } } Console.WriteLine(UnicodeEncoding.Unicode.GetString(text)); } }
Available since 10
.NET Framework
Available since 2.0
Silverlight
Available since 2.0
Windows Phone Silverlight
Available since 7.0