FileSystemWatcher问题

[htren]

_filewatcher=new FileSystemWatcher("c:","1.doc");

_filewatcher.IncludeSubdirectories=false;

//修改
_filewatcher.Changed+=new FileSystemEventHandler(OnChanged);
//删除
_filewatcher.Deleted+=new FileSystemEventHandler(OnDeleted);

_filewatcher.EnableRaisingEvents=true;

/// <summary>
/// 当修改文件后发生
/// </summary>
/// <param name="source"></param>
/// <param name="e"></param>
private void OnChanged(object source, FileSystemEventArgs e)
{
……………………
}

/// <summary>
/// 当删除文件后发生
/// </summary>
/// <param name="source"></param>
/// <param name="e"></param>
private void OnDeleted(object source, FileSystemEventArgs e)
{
……………………
}

用Word对1.doc进行修改后，没有触发OnChanged事件.
请高手们指点一下

[dazhu2]

private void button1_Click(object sender, System.EventArgs e)
{
FileSystemWatcher mywatch= new FileSystemWatcher();

mywatch.Path="f:\\";

//the file that is watched is what type
mywatch.Filter="*.doc";
//add event
mywatch.Renamed+=new RenamedEventHandler(this.rename_do);
mywatch.Changed+=new FileSystemEventHandler(this.change_do);

//start watch
mywatch.EnableRaisingEvents=true;


}


private void rename_do(object sender, System.IO.RenamedEventArgs e)
{
MessageBox.Show(e.OldName .ToString()+" 已改变！ ","rename提示");

MessageBox.Show(e.FullPath.ToString()+" 已改变！ ","rename提示");

MessageBox.Show(e.Name.ToString()+" 已改变！ ","rename提示");
}



private void change_do(object sender, System.IO.FileSystemEventArgs e)
{
string s=e.Name.ToString();
s=s.Replace("~$","");
if(s=="1.doc")
MessageBox.Show(e.FullPath.ToString()+" 已改变！ ","chang提示");
}

[htren]

不行!用Word打开1.doc时是产生一个changed事件,但是修改后保存没有产生事件.