Fixed DataGrid DoesNotContains filter throws No coercion operator is defined between types ‘System.String’ and ‘System.Boolean’

Author: enchev

Radzen.Blazor.Tests/ExpressionSerializerTests.cs

@@ -312,5 +312,12 @@ public void Serializes_ComplexExpressionWithProperties()
             Expression<Func<TestEntity, bool>> expr = e => e.Age > 18 && e.Tags.Contains("Member") || e.Address.City == "London";
             Assert.Equal("e => (((e.Age > 18) && e.Tags.Contains(\"Member\")) || (e.Address.City == \"London\"))", _serializer.Serialize(expr));
         }
+
+        [Fact]
+        public void Serializes_NotContains()
+        {
+            Expression<Func<TestEntity, bool>> expr = e => !e.Tags.Contains("Member");
+            Assert.Equal("e => (!(e.Tags.Contains(\"Member\")))", _serializer.Serialize(expr));
+        }
     }
 }

Radzen.Blazor/ExpressionSerializer.cs

@@ -138,9 +138,9 @@ protected override Expression VisitUnary(UnaryExpression node)
     {
         if (node.NodeType == ExpressionType.Not)
         {
-            _sb.Append("(!");
+            _sb.Append("(!(");
             Visit(node.Operand);
-            _sb.Append(")");
+            _sb.Append("))");
         }
         else if (node.NodeType == ExpressionType.Convert) 
         {