c# - if else if in while loop were else if test is defined in the first cycle -

somewhat confusing, when trying describe in title. here's example code. i'm hoping possible (i haven't found way yet.)

 datetime starttime = datetime.now;         int = 0;         bool running = true;         while (running)         {             datetime? lastruntime = null;             if (i == 0)             {                 if ((datetime.now - starttime).minutes >= program.gentimer)                 {                     = 1;                     lastruntime = datetime.now;                 }             }             else if ((datetime.now - lastruntime).minutes >= program.gentimer)             {                    //doestuff             } 

this looks foolish (and not work @ all, obvious being nullable timespan doesnt contain definition 'minutes. i've tried

datetime lastruntime; 

instead of

datetime? lastruntime = null; 

so i'm forcing first if statement true first time , false every pass afterward. i'm open different approach.

if you're curious, goal run in service runs through 11 operations 1 @ time on different time intervals. due how these operations processed, can't have more 1 run @ time.

if you're using nullable datetime, don't need i @ all. .hasvalue tell if it's been set or not. false first time. move out of while loop, otherwise you're redeclaring each time.

try like

datetime starttime = datetime.now; bool running = true; datetime? lastruntime = null; while (running) {     if (!lastruntime.hasvalue)     {         if ((datetime.now - starttime).minutes >= program.gentimer)         {             lastruntime = datetime.now;         }     }     else if ((datetime.now - lastruntime.value).minutes >= program.gentimer)     {             //doestuff     } }