Implementing a timeout in c#

As long as tryMethod() doesn't block this should do what you want:

Not safe for daylight savings time or changing time zones when mobile:

DateTime startTime = DateTime.Now;

while(true)
{
    tryMethod();
    if(DateTime.Now.Subtract(startTime).TotalMilliseconds > 5000)
        throw new TimeoutException();
}

Timezone and daylight savings time safe versions:

DateTime startTime = DateTime.UtcNow;

while(true)
{
    tryMethod();
    if(DateTime.UtcNow.Subtract(startTime).TotalMilliseconds > 5000)
        throw new TimeoutException();
} 

(.NET 3.5 or higher required for DateTimeOffset.)

DateTimeOffset startTime = DateTimeOffset.Now;

while(true)
{
    tryMethod();
    if(DateTimeOffset.Now.Subtract(startTime).TotalMilliseconds > 5000)
        throw new TimeoutException();
}