fauc3t

// UI View extension methods
public static class UIViewExtensions
{
  // Add these two static readonly variables
  private static readonly string COLOR_BORDERS_EXT = "color-borders-ext";
  private static readonly BorderDirection[] ALL_BORDERS = new BorderDirection[] { BorderDirection.Bottom, BorderDirection.Left, BorderDirection.Right, BorderDirection.Top };

  ...
}

fauc3t

// Method for coloring UIView borders
public static void ColorBorders(this UIView view, CGColor color, nfloat width, BorderDirection directions)
{
  // Loop through the four possible borders
  foreach(var border in ALL_BORDERS)
  {
    // Checks that the current border should be colored
    if((border & direction) == border)
    {
      //TODO

fauc3t

using CoreGraphics;
using System;
using UIKit;

namespace TextFieldValidation_Medium
{
  // UI View extension methods
  public static class UIViewExtensions
  {
    // Method for coloring UIView borders

fauc3t

// Checks that the current border should be colored
if((border & directions) == border)
{
	// Sublayer name
	var name = $"{COLOR_BORDERS_EXT}.{border.ToString()}";
	
	// Attempt to find sublayer by name
	var sublayer = view.Layer.Sublayers?.FirstOrDefault(layer => layer.Name != null &&
		layer.Name.Equals(name));
		

fauc3t

  }
} // End foreach loop on ALL_BORDERS

// Gets the border frame based on the direction provided
CGRect GetBorderFrame(BorderDirection border)
{
  switch(border)
  {
    case BorderDirection.Top:
      return new CGRect(0, 0, view.Frame.Width, width);

fauc3t

    ...

    sublayer.Frame = GetBorderFrame(border); // Border Frame
    sublayer.Name = name; // Name the sublayer
    sublayer.BorderWidth = width; // Set the border width
    sublayer.BorderColor = color; // Set the border color
  }
} // End foreach loop on ALL_BORDERS

fauc3t

public override void ViewDidLoad()
{
  base.ViewDidLayoutSubviews();
  NameTextField.ColorBorders(NameTextField.TextColor.CGColor, 4, BorderDirection.Bottom);
}

fauc3t

using CoreGraphics;
using System;
using UIKit;

namespace TextFieldValidation_Medium
{
  public class BorderedTextField
  {
    public UITextField TextField { get; set; }
    public CGColor BorderColor { get; set; }

fauc3t

NameTextField.ColorBorders(NameTextField.TextColor.CGColor, 4, BorderDirection.Bottom);

fauc3t

var borderedField = new BorderedTextField(NameTextField, NameTextField.TextColor.CGColor, BorderDirection.Bottom, 4);