SDI执行路径
一．DeleteContent：一般在销毁文档之前调用此函数，他是销毁文档中的数据，并不是销毁CDocument对象。另外，它还用来保证在重新加载文档之前该文档为NULL，在关闭一个文档时负责删除数据。单文档应用程序中只存在一个CDocument对象。
二．在单击‘File|New’时
函数调用顺序：
CWinApp::OnFileNew------>CDocManager::OnFileNew---------->CSingleDocmentTemplate::OnPenDocument------------>....
到此，程序执行回分两种情况（根据他的保护成员:lpszPathName是否为null来判断）：如果为空，则直接调用自己重载了的虚函数OnNewDocument。否则先调用OnOpenDocument
MFC源码如下:
1
void
CWinApp::OnFileNew()
2
{
3
if
(m_pDocManager
!=
NULL)
4
m_pDocManager
->
OnFileNew();
5
}
CDocManager::OnFileNew:
代码
void CDocManager::OnFileNew()
{
if (m_templateList.IsEmpty())
{
TRACE0("Error: no document templates registered with CWinApp.\n");
AfxMessageBox(AFX_IDP_FAILED_TO_CREATE_DOC);
return;
}
CDocTemplate* pTemplate = (CDocTemplate*)m_templateList.GetHead();
if (m_templateList.GetCount() > 1)
{
// more than one document template to choose from
// bring up dialog prompting user
CNewTypeDlg dlg(&m_templateList);
int nID = dlg.DoModal();
if (nID == IDOK)
pTemplate = dlg.m_pSelectedTemplate;
else
return; // none - cancel operation
}
ASSERT(pTemplate != NULL);
ASSERT_KINDOF(CDocTemplate, pTemplate);
pTemplate->OpenDocumentFile(NULL);
//事实上,pTemplate指向的是CSingleDocmentTemplate实例
// if returns NULL, the user has already been alerted
}
CSingleDocmentTemplate::OnPenDocument源码如下:
代码
1
CDocument
*
CSingleDocTemplate::OpenDocumentFile(LPCTSTR lpszPathName,
2
BOOL bMakeVisible)
3
//
if lpszPathName == NULL => create new file of this type
4
{
5
CDocument
*
pDocument
=
NULL;
6
CFrameWnd
*
pFrame
=
NULL;
7
BOOL bCreated
=
FALSE;
//
=> doc and frame created
8
BOOL bWasModified
=
FALSE;
9
10
if
(m_pOnlyDoc
!=
NULL)
11
{
12
//
already have a document - reinit it
13
pDocument
=
m_pOnlyDoc;
14
if
(
!
pDocument
->
SaveModified())
15
return
NULL;
//
leave the original one
16
17
pFrame
=
(CFrameWnd
*
)AfxGetMainWnd();
18
ASSERT(pFrame
!=
NULL);
19
ASSERT_KINDOF(CFrameWnd, pFrame);
20
ASSERT_VALID(pFrame);
21
}
22
else
23
{
24
//
create a new document
25
pDocument
=
CreateNewDocument();
26
ASSERT(pFrame
==
NULL);
//
will be created below
27
bCreated
=
TRUE;
28
}
29
30
if
(pDocument
==
NULL)
31
{
32
AfxMessageBox(AFX_IDP_FAILED_TO_CREATE_DOC);
33
return
NULL;
34
}
35
ASSERT(pDocument
==
m_pOnlyDoc);
36
37
if
(pFrame
==
NULL)
38
{
39
ASSERT(bCreated);
40
41
//
create frame - set as main document frame
42
BOOL bAutoDelete
=
pDocument
->
m_bAutoDelete;
43
pDocument
->
m_bAutoDelete
=
FALSE;
44
//
don't destroy if something goes wrong
45
pFrame
=
CreateNewFrame(pDocument, NULL);
46
pDocument
->
m_bAutoDelete
=
bAutoDelete;
47
if
(pFrame
==
NULL)
48
{
49
AfxMessageBox(AFX_IDP_FAILED_TO_CREATE_DOC);
50
delete pDocument;
//
explicit delete on error
51
return
NULL;
52
}
53
}
54
55
if
(lpszPathName
==
NULL)
56
{
57
//
create a new document
58
SetDefaultTitle(pDocument);
59
60
//
avoid creating temporary compound file when starting up invisible
61
if
(
!
bMakeVisible)
62
pDocument
->
m_bEmbedded
=
TRUE;
63
64
if
(
!
pDocument->
OnNewDocument())
65
{
66
//
user has been alerted to what failed in OnNewDocument
67
TRACE0(
"
CDocument::OnNewDocument returned FALSE.\n
"
);
68
if
(bCreated)
69
pFrame
->
DestroyWindow();
//
will destroy document
70
return
NULL;
71
}
72
}
73
else
74
{
75
CWaitCursor wait;
76
77
//
open an existing document
78
bWasModified
=
pDocument
->
IsModified();
79
pDocument
->
SetModifiedFlag(FALSE);
//
not dirty for open
80
81
if
(
!
pDocument
->
OnOpenDocument(lpszPathName))
82
{
83
//
user has been alerted to what failed in OnOpenDocument
84
TRACE0(
"
CDocument::OnOpenDocument returned FALSE.\n
"
);
85
if
(bCreated)
86
{
87
pFrame
->
DestroyWindow();
//
will destroy document
88
}
89
else
if
(
!
pDocument
->
IsModified())
90
{
91
//
original document is untouched
92
pDocument
->
SetModifiedFlag(bWasModified);
93
}
94
else
95
{
96
//
we corrupted the original document
97
SetDefaultTitle(pDocument);
98
99
if
(
!
pDocument->
OnNewDocument())
100
{
101
TRACE0(
"
Error: OnNewDocument failed after trying to open a document - trying to continue.\n
"
);
102
//
assume we can continue
103
}
104
}
105
return
NULL;
//
open failed
106
}
107
pDocument
->
SetPathName(lpszPathName);
108
}
109
110
CWinThread
*
pThread
=
AfxGetThread();
111
if
(bCreated
&&
pThread
->
m_pMainWnd
==
NULL)
112
{
113
//
set as main frame (InitialUpdateFrame will show the window)
114
pThread
->
m_pMainWnd
=
pFrame;
115
}
116
InitialUpdateFrame(pFrame, pDocument, bMakeVisible);
117
118
return
pDocument;
119
}
120
OnOpenDocument源码:
代码
1
BOOL CDocument::OnOpenDocument(LPCTSTR lpszPathName)
2
{
3
if
(IsModified())
4
TRACE0(
"
Warning: OnOpenDocument replaces an unsaved document.\n
"
);
5
6
CFileException fe;
7
CFile
*
pFile
=
GetFile(lpszPathName,
8
CFile::modeRead
|
CFile::shareDenyWrite,
&
fe);
9
if
(pFile
==
NULL)
10
{
11
ReportSaveLoadException(lpszPathName,
&
fe,
12
FALSE, AFX_IDP_FAILED_TO_OPEN_DOC);
13
return
FALSE;
14
}
15
16
DeleteContents();
17
SetModifiedFlag();
//
dirty during de-serialize
18
19
CArchive loadArchive(pFile, CArchive::load
|
CArchive::bNoFlushOnDelete);
20
loadArchive.m_pDocument
=
this
;
21
loadArchive.m_bForceFlat
=
FALSE;
22
TRY
23
{
24
CWaitCursor wait;
25
if
(pFile
->
GetLength()
!=
0
)
26
Serialize(loadArchive);
//
load me用于文档串行化:
27
loadArchive.Close();
28
ReleaseFile(pFile, FALSE);
29
}
30
CATCH_ALL(e)
31
{
32
ReleaseFile(pFile, TRUE);
33
DeleteContents();
//
remove failed contents
34
35
TRY
36
{
37
ReportSaveLoadException(lpszPathName, e,
38
FALSE, AFX_IDP_FAILED_TO_OPEN_DOC);
39
}
40
END_TRY
41
DELETE_EXCEPTION(e);
42
return
FALSE;
43
}
44
END_CATCH_ALL
45
46
SetModifiedFlag(FALSE);
//
start off with unmodified
47
48
return
TRUE;
49
}
50
三.单文档模板类创建了文档对象和框架窗口对象,然后在有框架窗口创建视图对象