FileStream.CanWrite Property
Gets a value indicating whether the current stream supports writing.
Assembly: mscorlib (in mscorlib.dll)
If a class derived from Stream does not support writing, a call to SetLength, Write, BeginWrite, or WriteByte throws a NotSupportedException.
If the stream is closed, this property returns false.
The following example uses the CanWrite property to check whether a stream supports writing.
using System; using System.IO; using System.Text; class Test { public static void Main() { string path = @"c:\temp\MyTest.txt"; // Ensure that the file is readonly. File.SetAttributes(path, File.GetAttributes(path) | FileAttributes.ReadOnly); //Create the file. using (FileStream fs = new FileStream (path, FileMode.OpenOrCreate, FileAccess.Read)) { if (fs.CanWrite) { Console.WriteLine("The stream for file {0} is writable.", path); } else { Console.WriteLine("The stream for file {0} is not writable.", path); } } } }
The following is an example using the CanWrite property. The output of this code is "MyFile.txt is writable." To get the output message "MyFile.txt can be both written to and read from.", change the FileAccess parameter to ReadWrite in the FileStream constructor.
using System; using System.IO; class TestRW { public static void Main(String[] args) { FileStream fs = new FileStream("MyFile.txt", FileMode.OpenOrCreate, FileAccess.Write); if (fs.CanRead && fs.CanWrite) { Console.WriteLine("MyFile.txt can be both written to and read from."); } else if (fs.CanWrite) { Console.WriteLine("MyFile.txt is writable."); } } }
Windows 7, Windows Vista SP1 or later, Windows XP SP3, Windows XP SP2 x64 Edition, Windows Server 2008 (Server Core not supported), Windows Server 2008 R2 (Server Core supported with SP1 or later), Windows Server 2003 SP2
The .NET Framework does not support all versions of every platform. For a list of the supported versions, see .NET Framework System Requirements.
