我有一个要在两个进程之间共享的json文件。所以我创建了一个内存映射文件,如下所示。
private void CreateMemoryMappedFile()
{
var info = Directory.CreateDirectory(Environment.GetFolderPath(Environment.SpecialFolder.CommonApplicationData) + "/" + model.Data.Settings.OrcaUISpecificSettings.TimeOutFolder);
string path = Path.Combine(info.FullName + @"\" + model.Data.Settings.OrcaUISpecificSettings.File);
FullPath = path;
try
{
mmf = MemoryMappedFile.CreateFromFile(path, FileMode.CreateNew, "MyMemoryFile", 1024 * 1024);
}
catch (Exception ex)
{
}
}
public MemoryMappedViewStream GetAccessor()
{
MemoryMappedViewStream FileMapView = null;
if (FileMapView != null)
{
return FileMapView;
}
FileMapView = mmf.CreateViewStream();
return FileMapView;
}
为了读取和写入文件,我执行了以下操作
public void WriteToMemoryMappedFile(string Data)
{
try
{
mutex.WaitOne();
byte[] bytes = Encoding.ASCII.GetBytes(Data);
var accessor = GetAccessor();
accessor.Write(bytes, 0, Data.Length);
mutex.ReleaseMutex();
}
catch (Exception ex)
{
}
}
public string ReadFromMemoryMappedFile()
{
mutex.WaitOne();
var accessor = GetAccessor();
using (BinaryReader binReader = new BinaryReader(accessor))
{
byte[] reader = binReader.ReadBytes((int)accessor.Length);
string result = Encoding.Default.GetString(reader);
mutex.ReleaseMutex();
return result.Replace("NULL", "");
}
}
我的问题是我的应用程序有一个活动监视器。所以在x次之后,我用InActiveStatus更新了json文件。同样的,我也在监听任何文件的变化(看看D_IDle事件)。问题是,如果一个普通的文件被更改,我会得到FileSytemWatcher changed事件,它会很好地触发。但是当我使用内存映射文件更新状态时,FileSystemWatcher changed事件永远不会触发,请帮助。
private void D_IsIdle(object sender, EventArgs e)
{
MonitorDirectory();
//AppViewModel.SerializeData("InActive");
AppViewModel.SerializeDataToMemoryMap("InActive");
d.IsIdle -= D_IsIdle;
}
public void MonitorDirectory()
{
FileSystemWatcher fileSystemWatcher = new FileSystemWatcher(AppViewModel.GetDriectory());
fileSystemWatcher.NotifyFilter = NotifyFilters.LastWrite;
fileSystemWatcher.Filter = "*.json";
fileSystemWatcher.Changed += FileSystemWatcher_Changed;
fileSystemWatcher.EnableRaisingEvents = true;
}
private void FileSystemWatcher_Changed(object sender, FileSystemEventArgs e)
{
//IT NEVER COMES HERE
}
发布于 2018-06-05 07:52:22
对内存映射文件使用FileSystemWatcher必须是某种反模式:)。如果您在本地系统上,请使用其中一个进程同步原语(例如信号量)来通知更改。
我的猜测是,FileSystemWatcher在文件句柄关闭时触发,以避免其他进程读取部分写入的文件。
https://stackoverflow.com/questions/50690204
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