Enterprise Management Information System Base On COM

With the rapid development of Networks and Communication, IS especial MIS is widely used. In them, Enterprise Management Information System is becoming an important measure to supervise production, to enhance management and to help decision-making for enterprise. At present, Enterprise Management Information System is usually constructed by 2-tiered C/S framework. There are several disadvantages in 2-tiered C/S framework, such as resource wasted seriously, connection of multiple users and multiple Databases,management of security,upgrade and maintenance of software becoming difficult. So software of Management Information System must be constructed by 3－tiered C/S framework. And the design and achievement of middle layer is key part to construct high efficiency,strong and secure MIS.The COM( Component Object Model, module object model) is a Microsoft to put forward a kind of according to the binary system standard has nothing to do with plait distance language software frame, it can make each software module use a kind of way that unify to proceed to hand over with each other. The COM defined the module procedure an environment for proceeding alternant standard, and also providing module procedure needing. In COM standard, the module procedure is divided into two kinds of: one is a kind of to call the module( in- process component) inside the progress, it is a development conjunction library DLLs generally; the other is a kind of to call the module( out- of- process component) outside the progress, it generally is a can carry out the procedure EXEs. Module procedure design be complicated of applied procedure design the some is small, single module in function mold piece, these modules mold piece can circulate on same pedestal machine or different machines on the even different operate system. Each module procedure cans use the different plait distance language environment to develop, edit and translate, adjust to try alone with test, combining them finally together must to complete applied procedure. When apply the need occurrence of the system the variety, to is module by the influence the mold piece proceed the modification, then integrates to get the new grade creep software afresh, but have no to need to proceed to edit and translate the modification to whole system. The module procedure strengthened consumedly the software replies to use the stability with the safety, making software proceeded to promote to higher grade with support by plug-and-play, lowering the cost, increases the efficiency that software produce.Language irrelevant, progress transparent, position transparent, safety with heavy use the characteristic is a COM basic characteristic. The COM provided the independent progress between transparent different from the correspondence automates, from but made an object as long as knew another the logic position of the object but need not to understand the concrete physics position of that object and then can proceed a correspondence, these objects can come from same machine of progress in network or different machine. The COM asks for help the RPC( Remote Procedure Call) come to realizes the different progress a method for of module object mutually corresponding by letter, passing native agency object with long range sharing an object, passing the row gather with spreading to gather realizes to apply the procedure has no to sew the conjunction, therefore and in the center the code of the layer exsits with heavy the module form of the binary system that use, its construction model. According to the module of COM procedure design makes develop the personnel even pays attention to the logical design in business, not first floor correspondence the details realizes.COM important part is how customer's procedure is hand over with server with each other. The server of COM is any to give the customer the procedure offering service of object. These services all connect the gossip with the COM now of the form appears, customer's procedure can get the needle of the server object connected i...