Facing problem in NSProgressIndicator to display progress of process.

Hi,

I am using NSProgressIndicator to display progress of process. for this i am using following code

            var progressIndicator = new NSProgressIndicator (new CGRect (50, 0, 400, 200)) 
            {
                DoubleValue = 0,
                Indeterminate = false
            } ;

            double progressValue = 0;
            totalItems = 50; //it can be changed according to parsed item. as 100, 1000, 9000.....
            //**progressIndicator.MinValue = 0;
            //**progressIndicator.MaxValue = totalItems;**
            while(progressValue < totalItems)
            {
                progressValue += 20;
                progressIndicator.DoubleValue = progressValue;
                mainWindowController.Window.ContentView.AddSubview (progressIndicator);// I also tried keep this line out side the loop 
            }
            //mainWindowController.Window.ContentView.AddSubview (progressIndicator);

            I also set progressInfo.progressIndicator.MaxValue = totalItems; . But progress is not being complete. Its being partially complete like 
            attached image. Where I am going wrong. Correct me.