一、根點是一個對象

.                                    +====================+.                                    |  MemberExPRession  |.                                    +====================+#                                      |                |#                          .Expression |                |#                                      v                v.                    +------------------+              +------------+.                    | MemberExpression |              | MemberInfo |.                    +------------------+              +------------+#                      |              |                 .Name = "Text"#          .Expression |              | .Member         .MemberType = Property#                      v              v.   +--------------------+          +------------+.   | ConstantExpression |          | MemberInfo |.   +--------------------+          +------------+#    .Value = this                   .Name = "textBox"#    .Type  = typeof(Form)           .MemberType = Field二、根點是一個靜態類
.                                    +====================+.                                    |  MemberExpression  |.                                    +====================+#                                      |                |#                          .Expression |                |#                                      v                v.                    +------------------+              +------------+.                    | MemberExpression |              | MemberInfo |.                    +------------------+              +------------+#                      |              |                 .Name = "Text"#          .Expression |              | .Member         .MemberType = Property#                      v              v.                     null          +------------+.                                   | MemberInfo |.                                   +------------+#                                   .Name = "textBox"#                                   .MemberType = Field#                                   .DeclaringType = typeof(Form)