net做的windows服务程序，如何与用户界面交互？
我用.net做了个windows服务程序，网上查到了些东西，可以弹出个winform用户界面来了，现在我想在服务中放个timer,定时的写些内容，并显示在winform用户界面中的textbox1里，该怎么做？我的大致代码如下(不成功):

public partial class Service_CARMS : ServiceBase
{
Form_Main f; //与用户交互的Form窗口
System.Threading.Thread threadform = null;
protected override void OnStart(string[] args)
{
threadform = new Thread(new ThreadStart(FormShow));
threadform.Start();

}

public void FormShow()
{

GetDesktopWindow();
IntPtr hwinstaSave = GetProcessWindowStation();
IntPtr dwThreadId = GetCurrentThreadId();
IntPtr hdeskSave = GetThreadDesktop(dwThreadId);
IntPtr hwinstaUser = OpenWindowStation("WinSta0", false, 33554432);
if (hwinstaUser == IntPtr.Zero)
{
RpcRevertToSelf();
return;
}
SetProcessWindowStation(hwinstaUser);
IntPtr hdeskUser = OpenDesktop("Default", 0, false, 33554432);
RpcRevertToSelf();
if (hdeskUser == IntPtr.Zero)
{
SetProcessWindowStation(hwinstaSave);
CloseWindowStation(hwinstaUser);
return;
}
SetThreadDesktop(hdeskUser);

IntPtr dwGuiThreadId = dwThreadId;

f = new Form_Main(); //此FORM1可以带notifyIcon，可以显示在托盘里，用户可点击托盘图标进行设置
System.Windows.Forms.Application.Run(f);


dwGuiThreadId = IntPtr.Zero;
SetThreadDesktop(hdeskSave);
SetProcessWindowStation(hwinstaSave);
CloseDesktop(hdeskUser);
CloseWindowStation(hwinstaUser);
}

[DllImport("user32.dll")]
static extern int GetDesktopWindow();

[DllImport("user32.dll")]
static extern IntPtr GetProcessWindowStation();

[DllImport("kernel32.dll")]
static extern IntPtr GetCurrentThreadId();

[DllImport("user32.dll")]
static extern IntPtr GetThreadDesktop(IntPtr dwThread);

[DllImport("user32.dll")]
static extern IntPtr OpenWindowStation(string a, bool b, int c);

[DllImport("user32.dll")]
static extern IntPtr OpenDesktop(string lpszDesktop, uint dwFlags,
bool fInherit, uint dwDesiredAccess);

[DllImport("user32.dll")]
static extern IntPtr CloseDesktop(IntPtr p);

[DllImport("rpcrt4.dll", SetLastError = true)]
static extern IntPtr RpcImpersonateClient(int i);


[DllImport("rpcrt4.dll", SetLastError = true)]
static extern IntPtr RpcRevertToSelf();

[DllImport("user32.dll")]
static extern IntPtr SetThreadDesktop(IntPtr a);

[DllImport("user32.dll")]
static extern IntPtr SetProcessWindowStation(IntPtr a);
[DllImport("user32.dll")]
static extern IntPtr CloseWindowStation(IntPtr a);

private void timer1_Tick(object sender, EventArgs e)
{
//MessageBox.Show("mm");
////////经调试发下以下代码异常,提示

/////"调用的目标发生了异常,..........{"未将对象引用设置到对象的实例
f.ShowInf("触发器触发"); //调用与用户交互的Form里的方法，该方法附加字符串到textbox1中。

}
}

救命啦

[解决办法]
timer用system的timer，不用form的timer
[解决办法]
怎么我看的都说不行呢。

例如:

http://stackoverflow.com/questions/5836977/show-status-window-from-windows-service
[解决办法]
既然带界面了，你为啥还选择window服务去做这样的事情呢？何不直接采用form程序？
[解决办法]

探讨

既然带界面了，你为啥还选择window服务去做这样的事情呢？何不直接采用form程序？

[解决办法]
分离2个程序，用socket/pipe/WINDOWS MESSAGE/MSMQ通讯
[解决办法]
最好单起个进程通过管道或SOCKET与服务进行通信，一方面操作更方便，另外还要保证winform把服务的可靠性。
[解决办法]
System.Threading.Timer