Please consider this example
TimeSpan timeSpan = new TimeSpan();
DateTime dtStart = DateTime.Now;
DateTime dtEnd = DateTime.Now.AddHours(1.5).AddDays(1);
timeSpan = dtEnd.Subtract(dtStart);
double hours = timeSpan.Hours + (timeSpan.Days * 24);
string time = string.Format("{0}hours and {1}minutes", hours, timeSpan.Minutes);
You can find the total hour as below code.
double hours = timeSpan.Hours + (timeSpan.Days * 24);
And this will also give you total hours
int totalHours = (int)timeSpan.TotalHours;
This will suppress the minutes and give you only hours.