Centre Scroll View Objects To Each Horizontal Scrolled Page - Xamarin iOS

Question

I am doing something very similar to this, https://www.youtube.com/watch?v=EwSTK24IQds, but for each object, I am placing a UI textfield. When I scroll through each page with different devices, the text does not centre to the middle of the screen. What would I have to do to make the object sit centre no matter what the device is? The user is filling out a form and is typing in data, and scrolling to the next page for each field.

Thanks

Answer 1

Cause:

The position of your textfield in different devices depending on your textfield's layout.

Solution:

For example, you add a textField to the default view of a ViewController.

I provide two methods here to center a textfield in the view no matter what the device is:

• The first is use Frame.You can calculate coordinates of the textfield in different device.

• The second is use Autolayout.You can add constraints to textfield to locate its position.

  public override void ViewDidLoad ()
  {
      base.ViewDidLoad ();
      // Perform any additional setup after loading the view, typically from a nib.
  
      UITextField myTextView = new UITextField();
      Add(myTextView);
  
      float ScreenWidth = (float)UIScreen.MainScreen.Bounds.Width;
      float ScreenHeight = (float)UIScreen.MainScreen.Bounds.Height;
  
      float textFieldWidth = 200;
      float textFieldHeight = 50;
  
      myTextView.Text = "center myTextView";
      myTextView.TextAlignment = UITextAlignment.Center;
      myTextView.BackgroundColor = UIColor.Blue;
  
      //Method One:
      //Frame Center
      //myTextView.Frame = new CGRect(new CGPoint(View.Center.X-textFieldWidth/2,View.Center.Y-textFieldHeight/2), new CGSize(textFieldWidth, textFieldHeight));
  
      //Frame
      //myTextView.Frame = new CGRect(ScreenWidth / 2 - textFieldWidth / 2, ScreenHeight / 2 - textFieldHeight / 2, textFieldWidth, textFieldHeight);
  
      //Method two:
      //autolayout
      //myTextView.TranslatesAutoresizingMaskIntoConstraints = false;
      //View.AddConstraint(NSLayoutConstraint.Create(myTextView, NSLayoutAttribute.Height, NSLayoutRelation.Equal, 1f, textFieldHeight));
      //View.AddConstraint(NSLayoutConstraint.Create(myTextView, NSLayoutAttribute.Width, NSLayoutRelation.Equal, 1f, textFieldWidth));
      //View.AddConstraint(NSLayoutConstraint.Create(myTextView, NSLayoutAttribute.CenterX, NSLayoutRelation.Equal, View, NSLayoutAttribute.CenterX, 1f, 10f));
      //View.AddConstraint(NSLayoutConstraint.Create(myTextView, NSLayoutAttribute.CenterY, NSLayoutRelation.Equal, View, NSLayoutAttribute.CenterY, 1f, 10f));
  
  }
  

Also,you can add constraints in storyboard: center a textfield in storyboard