From 1c9fe47d1ed6252a31102affe4860530b8ed1383 Mon Sep 17 00:00:00 2001
From: David Roqueni <45717673+DavidRoqueni@users.noreply.github.com>
Date: Wed, 3 Jul 2019 17:13:01 -0700
Subject: [PATCH] Add Color.ToHex() (#6272)

* Updated Color to have ToHex() method. Created Unit tests to ensure method is working as expected.

* Updated ToHex() use uint values. Updated unit tests for ToHex.
fixes #6003
---
 Xamarin.Forms.Core.UnitTests/ColorUnitTests.cs | 17 +++++++++++++++++
 Xamarin.Forms.Core/Color.cs                    | 11 ++++++++++-
 2 files changed, 27 insertions(+), 1 deletion(-)

diff --git a/Xamarin.Forms.Core.UnitTests/ColorUnitTests.cs b/Xamarin.Forms.Core.UnitTests/ColorUnitTests.cs
index 8668e5b..e217f5a 100644
--- a/Xamarin.Forms.Core.UnitTests/ColorUnitTests.cs
+++ b/Xamarin.Forms.Core.UnitTests/ColorUnitTests.cs
@@ -225,6 +225,23 @@ namespace Xamarin.Forms.Core.UnitTests
 		}
 
 		[Test]
+		public void TestToHex()
+		{
+			var colorRgb = Color.FromRgb(138, 43, 226);
+			Assert.AreEqual(Color.FromHex(colorRgb.ToHex()), colorRgb);
+			var colorRgba = Color.FromRgba(138, 43, 226,.2);
+			Assert.AreEqual(Color.FromHex(colorRgba.ToHex()), colorRgba);
+			var colorHsl = Color.FromHsla(240, 1, 1);	
+			Assert.AreEqual(Color.FromHex(colorHsl.ToHex()),colorHsl);
+			var colorHsla = Color.FromHsla(240, 1, 1,.1);
+			var hexFromHsla = Color.FromHex(colorHsla.ToHex());
+			Assert.That(hexFromHsla.A, Is.EqualTo(colorHsla.A).Within(0.002));
+			Assert.That(hexFromHsla.R, Is.EqualTo(colorHsla.R).Within(0.001));
+			Assert.That(hexFromHsla.G, Is.EqualTo(colorHsla.G).Within(0.001));
+			Assert.That(hexFromHsla.B, Is.EqualTo(colorHsla.B).Within(0.001));
+		}
+
+		[Test]
 		public void FromRGBDouble ()
 		{
 			var color = Color.FromRgb (0.2, 0.3, 0.4);
diff --git a/Xamarin.Forms.Core/Color.cs b/Xamarin.Forms.Core/Color.cs
index 305d833..c52ae6d 100644
--- a/Xamarin.Forms.Core/Color.cs
+++ b/Xamarin.Forms.Core/Color.cs
@@ -301,6 +301,15 @@ namespace Xamarin.Forms
 			return string.Format(CultureInfo.InvariantCulture, "[Color: A={0}, R={1}, G={2}, B={3}, Hue={4}, Saturation={5}, Luminosity={6}]", A, R, G, B, Hue, Saturation, Luminosity);
 		}
 
+		public string ToHex()
+		{
+			var red = (uint)(R * 255);
+			var green = (uint)(G * 255);
+			var blue = (uint)(B * 255);
+			var alpha = (uint)(A * 255);
+			return $"#{alpha:X2}{red:X2}{green:X2}{blue:X2}";
+		}
+
 		static uint ToHex (char c)
 		{
 			ushort x = (ushort)c;
@@ -311,7 +320,7 @@ namespace Xamarin.Forms
 			if (x >= 'a' && x <= 'f')
 				return (uint)(x - 'a' + 10);
 			return 0;
-		}
+		} 
 
 		static uint ToHexD (char c)
 		{
-- 
2.7.4