Document view Structure Analysis

Document view Structure Analysis

Theapp is a unique global variable. Its main function is to start the program by calling the encapsulated winmain main function. Shows the relationship between the main objects of an MFC application based on the document view framework. 1In the main framework (Cframewnd) To access the view (Cview) Getactiveview () Function: return the cview object of the activity. Prototype: cview * getactiveview () const; Note: The commonly used view is a cview derived class. before using the function in the derived class, you need to perform a type conversion, for example (cxxxview *) getactiveview ()-> myfunction (); This problem is caused by the parent class pointer and subclass pointer. 2In the View (Cview) To access the main framework (Cframewnd) Getparentframe () Function: return the cview object of the activity. Prototype: cframewnd * getparentframe () const; Note: the easiest way to obtain the main framework in a view is this. 3In the View (Cview) To access the Document Object (Cdocumet) Getdocument () Function: obtains the document pointer of a view. Prototype: cw.net * getdocument () const; Note: If you use Wizard to generate a document view structure, VC will automatically generate code similar to the following based on the project: # Ifndef _ debug Inline cxxxdoc * cxxxview: getdomainnet () {Return (cxxxdoc *) m_pdocument ;} # Endif 4In the document (Cdocument).View (Cview) Updateallviews (null) Function: notifies all views that the document object has been modified. Prototype: void updateallviews ( Cview * psender, // view pointer to be updated. If all views are updated, the value is set to null. Lparam lhint = 0l, // contains the notification for changing the message Cobject * phint = NULL) Note: Generally, updateallviews (null) is used to call the onupdate () virtual function of all views associated with the current document object. Cdocument: addview Function: Creates a connection between a view object and a Document Object (adds the view to a linked list and points the document pointer of the view to the document ). Cdocument: getfirstviewposition () cdocument: getnextview (POS) Function: Used to traverse view objects. 5Document Template object Create Document Object Csingledoctemplate () cmultidoctemplate () Function: the framework uses constructors to generate document objects and connects documents, frameworks, and views. 6Document Object Access Document Template object Getdoctemplate () getfirstdocposition () getnextdoc (POS) Function: in SDI, only one document object can be created for a document template. The two correspond One to One. Therefore, you can use getdoctemplate () to obtain a pointer to the document template. In MDI, A document template can create multiple document objects. Each document template instance maintains a Document Object List to store the associated document objects. getfirstdocposition () getnextdoc (POS) traverse all documents. 7Use less 8Document Template object Create Frame window object Csingledoctemplate () cmultidoctemplate () Function: the framework uses constructors to generate document objects and connects documents, frameworks, and views. 9Application Object PassCdocmanagerManagement Document Template object 10Application Object InInitinstance ()Create Document Template object