how to pass the multiple parameters to the system.threading.timer()

How can I pass multiple parameters to the callback expected by System.Threading.Timer() in C#?

timer1[timer] = new System.Threading.Timer(databaseTrensfer, row, dueTime, inte开发者_开发知识库rval);

public void databaseTrensfer(object row,object unitID)
{
   // do work here
}

How can I pass the second parameter to my databaseTrensfer function? Thanks in advance.

The timer callback is defined to take a single parameter:

public delegate void TimerCallback(object state);

If you need to pass several arguments to your callback, which are known when you register the callback on the Timer constructor, then you could use a lambda:

Timer CreateTimer(object unitID)
{
    object   row      = ...
    TimeSpan dueTime  = ...
    TimeSpan interval = ...

    return new Timer(x => DatabaseTransfer (x, unitID), row, dueTime, interval);
}

static void DatabaseTransfer(object row, object unitID)
{
    ....
}

Writing x => DataTransfer (x, unitID) captures the state of your unitID variable and is roughly equivalent to this:

Timer CreateTimer(object unitID)
{
    object   row      = ...
    TimeSpan dueTime  = ...
    TimeSpan interval = ...

    $Temp temp = new $Temp (unitID);

    return new Timer(temp.Callback, row, dueTime, interval);
}

class $Temp
{
    public $Temp(object arg)
    {
        this.arg = arg;
    }
    public void Callback(object x)
    {
        DataTransfer (x, this.arg);
    }
    private object arg;
}

The compiler takes care of constructing the class and plumbing behind the scenes. See for instance an explanation about closures.

Why not create a class that has properties consisting of the additional items you want to pass in? Then just pass the actual container class.