Imported Upstream version 4.0.0~alpha1

Former-commit-id: 806294f5ded97629b74c85c09952f2a74fe182d9

external/referencesource/System.Web/UI/WebControls/EmptyStringExpandableObjectConverter.cs

@@ -0,0 +1,30 @@
+//------------------------------------------------------------------------------
+// <copyright file="EmptyStringExpandableObjectConverter.cs" company="Microsoft">
+//     Copyright (c) Microsoft Corporation.  All rights reserved.
+// </copyright>
+//------------------------------------------------------------------------------
+
+namespace System.Web.UI.WebControls {
+
+    using System.ComponentModel;
+    using System.Globalization;
+    using System.Security.Permissions;
+
+
+    /// <devdoc>
+    /// Converts an object to String.Empty so it looks better in the designer property grid.
+    /// </devdoc>
+    internal sealed class EmptyStringExpandableObjectConverter : ExpandableObjectConverter {
+
+        /// <devdoc>
+        /// Returns String.Empty so the object looks better in the designer property grid.
+        /// </devdoc>
+        public override object ConvertTo(ITypeDescriptorContext context, CultureInfo culture, object value, Type destinationType) {
+            if (destinationType == typeof(string)) {
+                return String.Empty;
+            }
+            throw GetConvertToException(value, destinationType);
+        }
+    }
+}
+