Question

This is the view that appears when I click a button on a previous view.
The text boxes, the smiling face image and the labels are predesigned created by xCode.

Please see the image and the code of the view to clear why all the view’s components are initializing very slowly and getting ready to give the last shoot that is captured by me when it is finished to be totally loaded . Moreover, It is very slow when I type letters, the letters are appearing very slowly while I am typing with the keyboard that iOS provides on every touch on the text box.

The Code of The View;

using System;
using System.Drawing;

using MonoTouch.Foundation;
using MonoTouch.UIKit;

namespace IstanbulCity
{
    public partial class AskForNAme : UIViewController
    {
        public delegate void AskForNAmeClosingDelegate (AskForNAme form);

        public event AskForNAmeClosingDelegate AskForNAmeClosed;
        NSObject obs1;
        float scrollamount = 0.0f;
        float bottomPoint = 0.0f;
        float yOffset = 0.2f;
        bool moveViewUp = false;

        public AskForNAme () : base ("AskForNAme", null)
        {


        }

        public override void DidReceiveMemoryWarning ()
        {
            // Releases the view if it doesn't have a superview.
            base.DidReceiveMemoryWarning ();

            // Release any cached data, images, etc that aren't in use.
        }

        public override void ViewDidLoad ()
        {
            base.ViewDidLoad ();


            // Perform any additional setup after loading the view, typically from a nib.
        }
        public override void ViewDidAppear(bool animated)
        {
            base.ViewDidAppear(true);
                obs1 = NSNotificationCenter.DefaultCenter.AddObserver (
"UIKeyboardDidShowNotification", KeyboardUpNotification);
            this.tbOwnerMailAdress.ShouldReturn += TextFieldShouldReturn;
            this.tbOwnerBirthDay.ShouldReturn += TextFieldShouldReturn;
            this.uivGuguPhoto.Image = UIImage.FromFile ("image/fcuk.jpeg");

        }
        public override void ViewWillAppear(bool animated)
        {  
            base.ViewWillAppear(false);
            obs1 = NSNotificationCenter.DefaultCenter.AddObserver (
"UIKeyboardDidShowNotification", KeyboardUpNotification);
            this.tbOwnerMailAdress.ShouldReturn += TextFieldShouldReturn;
            this.tbOwnerBirthDay.ShouldReturn += TextFieldShouldReturn;
            this.uivGuguPhoto.Image = UIImage.FromFile ("image/fcuk.jpeg");

        }
        public override void ViewDidUnload ()
        {
            base.ViewDidUnload ();

            // Clear any references to subviews of the main view in order to
            // allow the Garbage Collector to collect them sooner.
            //
            // e.g. myOutlet.Dispose (); myOutlet = null;

            ReleaseDesignerOutlets ();
        }

        public override bool ShouldAutorotateToInterfaceOrientation (UIInterfaceOrientation toInterfaceOrientation)
        {
            // Return true for supported orientations
            return (toInterfaceOrientation != UIInterfaceOrientation.PortraitUpsideDown);
        }

        void HandleIstanbulCityViewControllerClosed (babyAge form)
        {
            form.DismissModalViewControllerAnimated (true);
            form = null;
        }



        partial void tbKadikoyHallEditDidEndOnExit (MonoTouch.Foundation.NSObject sender)
        {
            tbIstanbulName.ResignFirstResponder ();
        }



        private bool TextFieldShouldReturn (UITextField tf)
        {
            tf.ResignFirstResponder ();
            if (moveViewUp) {
                ScrollTheView (false);
            }
            return true;
        }

        private void KeyboardUpNotification (NSNotification notification)
        {
            ResetTheView ();

            RectangleF r = UIKeyboard.BoundsFromNotification (notification);

            if (this.tbOwnerMailAdress.IsEditing ) {
                //Calculate the bottom of the Texbox
                //plus a small margin...
                bottomPoint = (this.tbOwnerMailAdress.Frame.Y + this.tbOwnerMailAdress.Frame.Height + yOffset);

                //Calculate the amount to scroll the view
                //upwards so the Textbox becomes visible...
                //This is the height of the Keyboard -
                //(the height of the display - the bottom
                //of the Texbox)... 
                scrollamount = (r.Height - (View.Frame.Size.Height - bottomPoint));
            }
            else if (this.tbOwnerBirthDay.IsEditing)
            {
                bottomPoint = (this.tbOwnerBirthDay.Frame.Y + this.tbOwnerBirthDay.Frame.Height + yOffset);
                scrollamount = (r.Height - (View.Frame.Size.Height - bottomPoint));
            }
            else
            {
                scrollamount = 0;
            }

            //Check to see whether the view
            //should be moved up...
            if (scrollamount > 0) {
                moveViewUp = true;
                ScrollTheView (moveViewUp);
            }  else
                moveViewUp = false;
        }

        private void ResetTheView ()
        {
            UIView.BeginAnimations (string.Empty, System.IntPtr.Zero);
            UIView.SetAnimationDuration (0.3);

            RectangleF frame = View.Frame;
            frame.Y = 0;
            View.Frame = frame;
            UIView.CommitAnimations ();
        }

        private void ScrollTheView (bool movedUp)
        {
//To invoke a views built-in animation behaviour,
//you create an animation block and
//set the duration of the move...
//Set the display scroll animation and duration...
            UIView.BeginAnimations (string.Empty, System.IntPtr.Zero);
            UIView.SetAnimationDuration (0.3);

//Get Display size...
            RectangleF frame = View.Frame;

            if (movedUp) {
//If the view should be moved up,
//subtract the keyboard height from the display...
                frame.Y -= scrollamount;
            }  else {
//If the view shouldn't be moved up, restore it
//by adding the keyboard height back to the original...
                frame.Y += scrollamount;
            }

//Assign the new frame to the view...
            View.Frame = frame;

//Tell the view that your all done with setting
//the animation parameters, and it should
//start the animation...
            UIView.CommitAnimations ();

        }
    }
}

The Recent Version – Still The Same User Experience’ slow!

using System;
using System.Drawing;

using MonoTouch.Foundation;
using MonoTouch.UIKit;

namespace IstanbulCity
{
    public partial class AskForNAme : UIViewController
    {
        public delegate void AskForNAmeClosingDelegate (AskForNAme form);

        public event AskForNAmeClosingDelegate AskForNAmeClosed;


        public AskForNAme () : base ("AskForNAme", null)
        {


        }

        public override void DidReceiveMemoryWarning ()
        {
            // Releases the view if it doesn't have a superview.
            base.DidReceiveMemoryWarning ();

            // Release any cached data, images, etc that aren't in use.
        }

        public override void ViewDidLoad ()
        {
            base.ViewDidLoad ();


            // Perform any additional setup after loading the view, typically from a nib.
        }


        public override void ViewDidUnload ()
        {
            base.ViewDidUnload ();

            // Clear any references to subviews of the main view in order to
            // allow the Garbage Collector to collect them sooner.
            //
            // e.g. myOutlet.Dispose (); myOutlet = null;

            ReleaseDesignerOutlets ();
        }

        public override bool ShouldAutorotateToInterfaceOrientation (UIInterfaceOrientation toInterfaceOrientation)
        {
            // Return true for supported orientations
            return (toInterfaceOrientation != UIInterfaceOrientation.PortraitUpsideDown);
        }

        void HandleIstanbulCityViewControllerClosed (babyAge form)
        {
            form.DismissModalViewControllerAnimated (true);
            form = null;
        }







    }
}

Answer 1

This does not look to be initialization related. You are adding notifications from both ViewDidAppear and ViewWillAppear. You’re also always calling ResetTheView, which does animations, on every keyboard notification (even if nothing else changed).

My guess is that you are calling ResetTheView way more often that you realize – and the continuous animations are killing the performance of your application.

You can confirm this by putting a Console.WriteLine, and maybe a counter, in the ResetTheView method.