Draw a sequence:
The Document contains a CARET to indicate the cursor position, and the view is displayed from the Document to the specified position after obtaining the CARET position.
To simplify, Application represents the entire application, Singleton mode, you can use Application.instance () to get unique instances; Frame represents window, created by Application, and only one; View is created by frame, there is only one; Document is created by View And only one.
The entrance to the entire program is:
Public class application {???? public static void main (string [] args) {??????? Application App = Application.Instance (); ??????? app.run (); ???} ??? ...}
When the View receives the PAINT message, call the update () method to draw on the screen:
When Document changes the size of the user, call the DOCSIZECHANGED () to notify View, then call Update () update View:
