From 08273f800c29ba28bbc00c7be30d3eff9fccfd20 Mon Sep 17 00:00:00 2001
From: David Hall <dahall@byu.net>
Date: Mon, 30 Dec 2019 10:25:45 -0700
Subject: [PATCH] Added StringHelper.IsNullOrWhiteSpace to account for missing
 function prior to .NET 4. (#86)

---
 Core/Extensions/StringHelper.cs | 9 +++++++++
 1 file changed, 9 insertions(+)

diff --git a/Core/Extensions/StringHelper.cs b/Core/Extensions/StringHelper.cs
index 545bfeeb..d1273c07 100644
--- a/Core/Extensions/StringHelper.cs
+++ b/Core/Extensions/StringHelper.cs
@@ -1,4 +1,5 @@
 using System;
+using System.Linq;
 using System.Runtime.InteropServices;
 using System.Security;
 using Vanara.InteropServices;
@@ -210,6 +211,14 @@ namespace Vanara.Extensions
 		/// </returns>
 		public static string GetString(IntPtr ptr, int length, CharSet charSet = CharSet.Auto) => GetString(ptr, charSet, length * GetCharSize(charSet));
 
+		/// <summary>Indicates whether a specified string is <see langword="null"/>, empty, or consists only of white-space characters.</summary>
+		/// <param name="value">The string to test.</param>
+		/// <returns>
+		/// <see langword="true"/> if the <paramref name="value"/> parameter is <see langword="null"/> or <see cref="string.Empty"/>, or if
+		/// value consists exclusively of white-space characters.
+		/// </returns>
+		public static bool IsNullOrWhiteSpace(string value) => value is null || value.All(c => char.IsWhiteSpace(c));
+
 		/// <summary>Refreshes the memory block from the unmanaged COM task allocator and copies the contents of a new managed String.</summary>
 		/// <param name="ptr">The address of the first character.</param>
 		/// <param name="charLen">Receives the new character length of the allocated memory block.</param>