GetTemplateParameter method in DynamicParameters

Dapper/DynamicParameters.cs

@@ -329,6 +329,39 @@ public T Get<T>(string name)
             return (T)val;
         }
 
+        /// <summary>
+        /// Param names from templates
+        /// </summary>
+        public IEnumerable<string> TemplateParameterNames => templates.Select(t => t.GetType().GetProperties().Select(p => p.Name)).SelectMany(p => p);
+
+        /// <summary>
+        /// Get the value of a parameter that was created from a template
+        /// </summary>
+        /// <typeparam name="T">The type of a parameter</typeparam>
+        /// <param name="name"></param>
+        /// <returns>The value of the parameter</returns>
+        /// <exception cref="Exception">When templates is null or the param wasn't found</exception>
+        public T GetTemplateParameter<T>(string name)
+        {
+            if (templates == null)
+                throw new Exception("There are no templates");
+
+            foreach (object t in templates)
+            {
+                var property = t.GetType().GetProperties().Where(p => p.Name == name).FirstOrDefault();
+
+                if (property != null)
+                    return (T)property.GetValue(t);
+            }
+
+            throw new Exception($"Parameter name {name} not present in templates");
+        }
+
+        /// <summary>
+        /// Param names from templates and bag
+        /// </summary>
+        public IEnumerable<string> AllParameterNames => ParameterNames.Concat(TemplateParameterNames);
+
         /// <summary>
         /// Allows you to automatically populate a target property/field from output parameters. It actually
         /// creates an InputOutput parameter, so you can still pass data in.

tests/Dapper.Tests/ParameterTests.cs

@@ -1593,5 +1593,29 @@ private static int GetExpectedListExpansionCount(int count, bool enabled)
             if (delta != 0) blocks++;
             return blocks * padFactor;
         }
+
+        [Fact]
+        public void TestGetParameterFromAnonymousType()
+        {
+            // https://github.com/DapperLib/Dapper/issues/343
+            // https://github.com/DapperLib/Dapper/issues/1113
+
+            var parameters = new DynamicParameters(new { par = 1 });
+
+            Assert.Equal(1, parameters.GetTemplateParameter<int>("par"));
+            Assert.Equal("par", parameters.TemplateParameterNames.First());
+        }
+
+        [Fact]
+        public void TestGetAllParemeters()
+        {
+            var parameters = new DynamicParameters(new { par1 = 1 });
+            parameters.Add("par2", 2);
+
+            var paramNames = parameters.AllParameterNames.ToList();
+
+            Assert.Equal("par2", paramNames[0]);
+            Assert.Equal("par1", paramNames[1]);
+        }
     }
 }