正由另一进程使用，因此该进程无法访问该文件
/// <summary>
/// 写入日志
/// </summary>
/// <param name="log"></param>
private void WriteLog(string log)
{
//edit at 2012.10.17 改成无锁异步写如日志文件
using (FileStream fs = new FileStream(DataLogFile, FileMode.Append, FileAccess.Write, FileShare.Write, 1024, FileOptions.Asynchronous))
{
byte[] buffer = System.Text.Encoding.UTF8.GetBytes(log+"\r\n");
IAsyncResult writeResult = fs.BeginWrite(buffer, 0, buffer.Length,
(asyncResult) =>
{
FileStream fStream = (FileStream)asyncResult.AsyncState;
fStream.EndWrite(asyncResult);
},
fs);
//fs.EndWrite(writeResult);//这种方法异步起不到效果
fs.Close();
}
//lock (lockObj)
//{
// //using (StreamWriter sw = File.AppendText(DataLogFile))
// //{
// // sw.WriteLine(log);
// // sw.Flush();
// // sw.Close();
// //}
//}
}class Program
{
static
void
Main(
string
[] args)
{
ThreadPool.QueueUserWorkItem(run);
ThreadPool.QueueUserWorkItem(run);
Console.ReadLine();
}
private
static
void
run(
object
state)
{
while
(
true
)
{
Append();
}
}
public
static
void
Append()
{
try
{
//lock (typeof(Program))
//{
using
(var writer = File.AppendText(
"1.txt"
))
{
writer.Write(DateTime.Now.ToString(
"HHmmss"
));
}
Console.WriteLine(
"Done"
);
//}
}
catch
(Exception ex)
{
Console.WriteLine(ex);
}
}
}
static System.Threading.Semaphore _mutex = new System.Threading.Semaphore( 1 , 1 , " IOHelper.Save " );
private static bool Save( string fileName, string text, bool isAppend)
{
try
{
if (_mutex.WaitOne( 2000 , false )) // 进程间同步。
{
using (StreamWriter writer = new StreamWriter(fileName, isAppend))
{
writer.Write(text);
}
}
return true ;
}
catch (Exception err)
{
Log.WriteLogToTxt(err);
}
finally
{
try
{
_mutex.Release();
}
catch
{
}
}
return false ;
}