How to Implement code refactoring?

How to Implement code refactoring?

In the past few days, I have taken over the code of a colleague, and the pile of if related to interface development seems so painful. This problem is also easy for many new users, so I wrote this refactoring specially.

Let's take a look at the problem with this Code. The code block logic in if else is hard to modify, making it reusable 0 and hard to read. Of course, if there are only one or two or three if, this is not a problem.

However, if there is more code, it will make maintenance difficult.

If (strMsgType = "text ")

{

TextContentClient = rootElement. SelectSingleNode ("Content"). InnerText;

StrResult = SetMsgType_Text (strClientName, textContentClient, db, strServerName, Identity );

System. Diagnostics. Trace. WriteLine (strResult );

Return Content (strResult );

}

Else if (strMsgType = "event ")

{

String eventType = rootElement. SelectSingleNode ("Event"). InnerText. ToLower ();

If (eventType = "subscribe ")

{

String keyCode = "";

If (rootElement. SelectSingleNode ("EventKey ")! = Null)

KeyCode = rootElement. SelectSingleNode ("EventKey"). InnerText. ToLower ();

StrResult = FormatEventSubscribe (keyCode );

RecordReplyMessage ();

Return Content (strResult );

}

Else if (eventType = "scan ")

{

String keyCode = rootElement. SelectSingleNode ("EventKey"). InnerText. ToLower ();

Var outLetName = "welcome ";

Var outletDB = ShoppingContext. CreateInstance (Identity );

Var outLetModel = outletDB. Outlets. FirstOrDefault (o => o. SceneId = Int32.Parse (keyCode ));

If (outLetModel! = Null)

OutLetName + = outLetModel. Name;

Return Content (GetTextTemp (strClientName, strServerName, outLetName ));

}

Else if (eventType = "click ")

{

String keyCode = rootElement. SelectSingleNode ("EventKey"). InnerText. ToLower ();

StrResult = FomatMenuMessage (keyCode );

Return Content (strResult );

}

Else if (eventType = "unsubscribe ")

{

Var subIds = db. replyRecords. where (r => r. fromOpenId = this. clientId. toString () & r. EMessType = EEventType. subscribe. toString () & r. keyWord! = Null). Select (o => o. KeyWord). ToArray ();

Var unSubIds = db. replyRecords. where (r => r. fromOpenId = this. clientId. toString () & r. EMessType = EEventType. unsubscribe. toString () & r. keyWord! = Null). Select (o => o. KeyWord). ToArray ();

Var SencesId = "";

Foreach (var k in subIds)

{

If (! UnSubIds. Contains (k ))

{

This. ReplyModel. KeyWord = k;

Break;

}

}

This. ReplyModel. EMessType = EEventType. Unsubscribe. ToString ();

RecordReplyMessage ();

}

}

Else if (strMsgType. ToLower () = "location ")

{

String strLocation_X = rootElement. SelectSingleNode ("Location_X"). InnerText;

String strLocation_Y = rootElement. SelectSingleNode ("Location_Y"). InnerText;

StrResult = FormatOutLetLBS (double. Parse (strLocation_X), double. Parse (strLocation_Y), 10 );

// StrResult = FormatTextMessage (strLocation_X + "|" + strLocation_Y );

Return Content (strResult );

}

Else if (strMsgType. ToLower () = "image ")

{

String strImgUrl = rootElement. SelectSingleNode ("PicUrl"). InnerText;

}

A better solution is to extract the code in the statement block and write it as a function, as shown below:

Public class MessageProcesser

{

Public ReplyMessage Process (string xml)

{

Var msg = PostMessage. FromXml (xml );

Switch (msg. MsgType)

{

Case Models. PostMessageType. Event:

Var eventType = (EventMessage) msg). Event;

Switch (eventType)

{

Case EventType. Click:

Return ProcessClickEvent (ClickEvent) msg );

Case EventType. Location:

Return ProcessLocationEvent (LocationEvent) msg );

Case EventType. Scan:

Return ProcessScanEvent (ScanEvent) msg );

Case EventType. Subscribe:

Return ProcessSubscribeEvent (SubscribeEvent) msg );

Case EventType. Unsubscribe:

Return ProcessUnsubscribeEvent (UnsubscribeEvent) msg );

}

Break;

Case Models. PostMessageType. Image:

Return ProcessImageMessage (ImageMessage) msg );

Case Models. PostMessageType. Link:

Return ProcessLinkMessage (LinkMessage) msg );

Case Models. PostMessageType. Location:

Return ProcessLocationMessage (LocationMessage) msg );

Case Models. PostMessageType. Text:

Return ProcessTextMessage (TextMessage) msg );

Case Models. PostMessageType. Video:

Return ProcessVideoMessage (VideoMessage) msg );

Case Models. PostMessageType. Voice:

Return ProcessVoiceMessage (VoiceMessage) msg );

}

Return null;

}

Protected virtual ReplyMessage ProcessClickEvent (ClickEvent msg)

{

Return DefaultProcess (msg );

}

Protected virtual ReplyMessage ProcessLocationEvent (LocationEvent msg)

{

Return DefaultProcess (msg );

}

Protected virtual ReplyMessage ProcessScanEvent (ScanEvent msg)

{

Return DefaultProcess (msg );

}

Protected virtual ReplyMessage ProcessSubscribeEvent (SubscribeEvent msg)

{

Return DefaultProcess (msg );

}

Protected virtual ReplyMessage ProcessUnsubscribeEvent (UnsubscribeEvent msg)

{

Return DefaultProcess (msg );

}

Protected virtual ReplyMessage ProcessImageMessage (ImageMessage msg)

{

Return DefaultProcess (msg );

}

Protected virtual ReplyMessage ProcessLinkMessage (LinkMessage msg)

{

Return DefaultProcess (msg );

}

Protected virtual ReplyMessage ProcessLocationMessage (LocationMessage msg)

{

Return DefaultProcess (msg );

}

Protected virtual ReplyMessage ProcessTextMessage (TextMessage msg)

{

Return DefaultProcess (msg );

}

Protected virtual ReplyMessage ProcessVideoMessage (VideoMessage msg)

{

Return DefaultProcess (msg );

}

Protected virtual ReplyMessage ProcessVoiceMessage (VoiceMessage msg)

{

Return DefaultProcess (msg );

}

Protected virtual ReplyMessage DefaultProcess (PostMessage msg)

{

Var reply = new TextReply (msg );

If (msg. MsgType = PostMessageType. Event)

{

Reply. Content = string. Format ("{0} event is not processed.", (EventMessage) msg). Event );

}

Else

{

Reply. Content = string. Format ("{0} message is not processed.", msg. MsgType );

}

Return reply;

}

}