Update ColorToStringConverter.shared.cs

src/CommunityToolkit.Maui.UnitTests/Converters/ColorToHexArgbStringConverterTests.cs

@@ -0,0 +1,80 @@
+using CommunityToolkit.Maui.Converters;
+using Xunit;
+
+namespace CommunityToolkit.Maui.UnitTests.Converters;
+public class ColorToHexArgbStringConverterTests : BaseConverterTest<ColorToHexArgbStringConverter>
+{
+	public static readonly IReadOnlyList<object[]> ValidInputData =
+	[
+		[int.MinValue, int.MinValue, int.MinValue, int.MinValue, "#00000000"],
+		[int.MaxValue, int.MinValue, int.MinValue, int.MinValue, "#FF000000"],
+		[int.MinValue, 0, 0, 0, "#00000000"],
+		[-0.5, 0, 0, 0, "#00000000"],
+		[0, 0, 0, 0, "#00000000"],
+		[0.5, 0, 0, 0, "#7F000000"],
+		[1, 0, 0, 0, "#FF000000"],
+		[int.MaxValue, 0, 0, 0, "#FF000000"],
+		[int.MinValue, int.MaxValue, int.MaxValue, int.MaxValue, "#00FFFFFF"],
+		[int.MaxValue, int.MaxValue, int.MaxValue, int.MaxValue, "#FFFFFFFF"],
+		[0, 1, 0, 0, "#00FF0000"],
+		[1, 1, 0, 0, "#FFFF0000"],
+		[0, 1, 1, 0, "#00FFFF00"],
+		[1, 1, 1, 0, "#FFFFFF00"],
+		[0, 0, 1, 0, "#0000FF00"],
+		[1, 0, 1, 0, "#FF00FF00"],
+		[0, 0, 1, 1, "#0000FFFF"],
+		[1, 0, 1, 1, "#FF00FFFF"],
+		[0, 1, 0, 1, "#00FF00FF"],
+		[1, 1, 0, 1, "#FFFF00FF"],
+		[0, 0, 0.5, 1, "#00007FFF"],
+		[0, 0, 0.5, 0, "#00007F00"],
+		[0.5, 0.5, 0.5, 1, "#7F7F7FFF"],
+		[0.5, 0.5, 0.5, 0, "#7F7F7F00"],
+		[0.25, 0.25, 0.25, 1, "#3F3F3FFF"],
+		[0.25, 0.25, 0.25, 0, "#3F3F3F00"],
+		[0.25, 1, 0.25, 1, "#3FFF3FFF"],
+		[0.25, 1, 0.25, 0, "#3FFF3F00"],
+		[0.75, 1, 0.25, 1, "#BFFF3FFF"],
+		[0.75, 1, 0.25, 0, "#BFFF3F00"],
+		[0.75, 0, 1, 1, "#BF00FFFF"],
+		[0.75, 0, 1, 0, "#BF00FF00"]
+	];
+
+	[Theory]
+	[MemberData(nameof(ValidInputData))]
+	public void ColorToHexArgbStringConverterValidInputTest(float alpha, float red, float green, float blue, string expectedResult)
+	{
+		var converter = new ColorToHexArgbStringConverter();
+		var color = new Color(red, green, blue, alpha);
+
+		var resultConvert = ((ICommunityToolkitValueConverter)converter).Convert(color, typeof(string), null, null);
+		var resultConvertFrom = converter.ConvertFrom(color);
+
+		Assert.Equal(expectedResult, resultConvert);
+		Assert.Equal(expectedResult, resultConvertFrom);
+	}
+
+	[Theory]
+	[MemberData(nameof(ValidInputData))]
+	public void ColorToHexArgbStringConverterConvertBackValidInputTest(float alpha, float red, float green, float blue, string expectedResult)
+	{
+		var converter = new ColorToHexArgbStringConverter();
+		var color = new Color(red, green, blue, alpha);
+
+		var resultConvert = ((ICommunityToolkitValueConverter)converter).ConvertBack(expectedResult, typeof(Color), null, null);
+		var resultConvertTo = converter.ConvertBackTo(expectedResult);
+
+		Assert.Equal(color, resultConvert);
+		Assert.Equal(color, resultConvertTo);
+	}
+
+	[Fact]
+	public void ColorToHexArgbStringConverterNullInputTest()
+	{
+#pragma warning disable CS8625 // Cannot convert null literal to non-nullable reference type.
+		Assert.Throws<ArgumentNullException>(() => new ColorToHexArgbStringConverter().ConvertFrom(null));
+		Assert.Throws<ArgumentNullException>(() => ((ICommunityToolkitValueConverter)new ColorToHexArgbStringConverter()).Convert(null, typeof(string), null, null));
+		Assert.Throws<ArgumentNullException>(() => ((ICommunityToolkitValueConverter)new ColorToHexArgbStringConverter()).Convert(new Color(), null, null, null));
+#pragma warning restore CS8625 // Cannot convert null literal to non-nullable reference type.
+	}
+}

src/CommunityToolkit.Maui/Converters/ColorToStringConverter.shared.cs

@@ -116,6 +116,32 @@ public override Color ConvertBackTo(string value, CultureInfo? culture = null)
 	}
 }
 
+/// <summary>
+/// Converts the incoming value from <see cref="Color"/> and returns the object of a type <see cref="string"/> and vice-versa.
+/// </summary>
+public class ColorToHexArgbStringConverter : BaseConverter<Color, string>
+{
+	/// <inheritdoc/>
+	public override string DefaultConvertReturnValue { get; set; } = string.Empty;
+
+	/// <inheritdoc/>
+	public override Color DefaultConvertBackReturnValue { get; set; } = Colors.Transparent;
+
+	/// <inheritdoc/>
+	public override string ConvertFrom(Color value, CultureInfo? culture = null)
+	{
+		ArgumentNullException.ThrowIfNull(value);
+		return value.ToArgbHex(true);
+	}
+
+	/// <inheritdoc/>
+	public override Color ConvertBackTo(string value, CultureInfo? culture = null)
+	{
+		ArgumentNullException.ThrowIfNull(value);
+		return Color.FromArgb(value);
+	}
+}
+
 /// <summary>
 /// Converts the incoming value from <see cref="Color"/> and returns the object of a type <see cref="string"/>.
 /// </summary>
@@ -178,4 +204,4 @@ public override string ConvertFrom(Color value, CultureInfo? culture = null)
 		ArgumentNullException.ThrowIfNull(value);
 		return value.ToHslaString(culture);
 	}
-}
+}