Building Applications Using VC

8/8/2019 Building Applications Using VC

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Building Applications Using VC++

Overview of OOP

OOP is about trying to represent the Objects that we find in the realworld ( or at least that part of which programs address ) in software.

WHAT IS OBJECT ?

Objects are the elements through which we perceive the world around us,which have recognizable identities and particular behaviors.

These Objects may be of various types, ranging from the physical to themore conceptual.

In OOP there is mainly two kinds of Objects :

Those that directly represent the ideas used to describe the application

Those that are used as programming tools to implement code

Object = (private) data + (public) processes

Objects have a private part of hidden internal detail, and a

public interface which clearly defines the set of possible

behaviors of the object.

Areas of Object technology

The general field of object technology can be seen as falling into four areaof application :

OOP

OOD

OOA

OODBs


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Key Features of OOP

Abstraction / encapsulation

Inheritance

Polymorphism

Abstraction / encapsulation

It the representation of all the essential features of an object, whichmeans its possible states & behaviors.

Encapsulation is the practice of including in an object everything it needs,(both data & processes) hidden from other objects in the system. Theinternal state of an object is not directly accessible from outside, and

cannot be altered by external changes to the application.Changes to the internal implementation details can be made withoutaffecting the external interface.

Inheritance

Inheritance means that one class inherits the characteristics of another classas part of its definition. It appropriate when one class is a kind of otherclass (e.g. A is a kind of B text window is a kind of window). These typesof hierarchies are fundamental to OOP. Some classes may inherit from more

than one other class, (multiple inheritance).

Inheritance has two complementary roles :

1. To allow class to be extended so that its existing functionality can bebuilt on for new applications.

2. To allow similar objects to share their common properties & allowedbehaviors.

3. Polymorphism

4. It means having many forms. The general description of polymorphism is that it allows different objects to respond to the samemessage in different ways, the response specific to the type of object.This is achieved by various types of overloading - allowing asymbol ( operator like +) to have more than one meaning dependingon the context in which it is used.


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5. Polymorphism is particularly important when object oriented programsare dynamically creating & destroying objects in a classificationhierarchy at run time.

MFC Introduction

Microsoft created a group called the AFX group (stands for(A)pplication (F)ramework(X)).

They came up with a class library that presented a very highabstraction from the Windows API.

The AFX group was actually responsible for two things: theMFC library and the IDE's support for MFC (namely, theresource editor and the wizards).

MFC Classes

CObject CException CBrush CListBox

CWinApp CMemoryException CFont CComboBox

CMenu CNotSupportedException

CBitmap CScrollBar

CArchive CArchiveException CPalette

CDumpContext

CFileException CRgn

CRuntimeClass

CResourceException CWnd

CMemoryState

CFile CFrameWnd

CFileStatus CDC CMDIChildWnd

CString CClientDC CMDIFrameWnd


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CTime CWindowDC CDialog

CTimeSpan CPaintDC CModalDialog

CPoint CMetaFileDC CStatic

CRect CGdiObject CButton

CSize CPen CEdit

CObject CException CBrush CListBox

CWinApp CMemoryException CFont CComboBo

x

CMenu CNotSupportedException

CBitmap CScrollBar

CArchive CArchiveException CPalette

CDumpContext

CFileException CRgn

CRuntimeClass

CResourceException CWnd

CMemoryState

CFile CFrameWnd

CFileStatus CDC CMDIChildWnd

CString CClientDC CMDIFrameWnd

CTime CWindowDC CDialog

CTimeSpan CPaintDC CModalDialog

CPoint CMetaFileDC CStatic


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CRect CGdiObject CButton

CSize CPen CEdit

The Visual C++ Development Environment

The Workspace

When you start Visual C++ for the first time, an area on the left side of Developer Studio looks like it is taking up a lot of real estate andproviding little to show for it. This area is known as the workspace, andit is your key to navigating the various pieces and parts of your


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development projects. The workspace allows you to view the parts of your application in three different ways:

Class View allows you to navigate and manipulate your source codeon a C++ class level.

Resource View allows you to find and edit each of the variousresources in your application, including dialog window designs, icons,and menus.

File View allows you to view and navigate all the files that make upyour application.


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The Output Pane

The Output pane might not be visible when you start Visual C++ for

the first time. After you compile your first application, it appears at thebottom of the Developer Studio environment and remains open untilyou choose to close it.

The Output pane is where Developer Studio provides any informationthat it needs to give you; where you see all the compiler progressstatements, warnings, and error messages; and where the Visual C++debugger displays all the variables with their current values as youstep through your code.

After you close the Output pane, it reopens itself when Visual C++ hasany message that it needs to display for you.

Starting Your First Project

Creating the Project Workspace

Every application development project needs its own projectworkspace in Visual C++. The workspace includes thedirectories where the application source code is kept, as wellas the directories where the various build configuration filesare located. You can create a new project workspace byfollowing these steps:

1. Select File | New. This opens the New Wizard

2. On the Projects tab, select MFC AppWizard (exe).

3. Type a name for your project, such as Hello, in theProject Name field.

4. Click OK.

This causes the New Wizard to do two things: create a projectdirectory (specified in the Location field) and then start theAppWizard.


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Using the Application Wizard to Create the Application Shell

The AppWizard asks you a series of questions about what typeof application you are building and what features andfunctionality you need. It uses this information to create ashell of an application that you can immediately compile andrun. This shell provides you with the basic infrastructure thatyou need to build your application around. You will see howthis works as you follow these steps:

In Step 1 of the AppWizard, specify that you want tocreate a Dialog-based application. Click Next at thebottom of the wizard.


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In Step 2 of the AppWizard, the wizard asks you about anumber of features that you can include in your application.

You can uncheck the option for including support for ActiveXcontrols if you will not be using any ActiveX controls in yourapplication.

Because you won't be using any ActiveX controls inapplication, go ahead and uncheck this box.


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The final step of the AppWizard shows you the C++classes that the AppWizard will create for yourapplication.

Click Finish to let AppWizard generate your applicationshell.

Before AppWizard creates your application shell, itpresents you with a list of what it is going to put into the

application shell, based on the options you selected whengoing through the AppWizard.

Click OK and AppWizard generates your application.


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After the AppWizard generates your application shell, you are returnedto the Developer Studio environment.

You will notice that the workspace pane now presents you with a treeview of the classes in your application shell.

You might also be presented with the main dialog window in the editorarea of the Developer Studio area.


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To Build and Execute the project

Select Build | Build Hello.exe to compile your application.

As the Visual C++ compiler builds your application, you seeprogress and other compiler messages scroll by in the Outputpane. After your application is built, the Output pane shoulddisplay a message telling you that there were no errors orwarnings.

The Output pane displays ( if )any compiler errors.

Select Build | Execute Hello.exe to run your application.

Your application presents a dialog with a TODO message and OK and Cancel buttons


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You can click either button to close the application.

Adding Code to Your Application

You can attach code to your dialog through the Visual C++ ClassWizard.

You can use the Class Wizard to build the table of Windows messagesthat the application might receive, including the functions they shouldbe passed to for processing, that the MFC macros use for attaching

functionality to window controls.

You can attach the functionality for this first application by followingthese steps:

To attach some functionality to the Hello button, right-click overthe button and select Class Wizard from the pop-up menu.


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With IDHELLO selected in the Object ID list, select BN_CLICKED inthe list of messages and click Add Function. This opens the AddMember Function dialog

This dialog contains a suggestion for the function name. Click OK to create the function and add it to the message map.

Finishing Touches

Now that your application is functionally complete, you can still add a

few details to finish off the project. Those finishing touches includeCreating the dialog box icon

Adding maximize and minimize buttons

Creating the Dialog Box Icon


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In the tree view of your application resources in the workspace pane,expand the icon branch and select the IDR_MAINFRAME icon.

This brings the application icon into the editor area of the DeveloperStudio.

Using the painting tools provided, repaint the icon to display an imagethat you want to use to represent your application,

Adding Maximize and Minimize Buttons

In the dialog editor, where you design your application window, youcan add the minimize and maximize buttons to the title bar of yourapplication window by following these steps:

Select the dialog window itself as if you were going to resize thewindow.


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Using the pop-up menu (from right-clicking the mouse), selectthe dialog properties.

Select the Styles tab

After you turn on the minimize and maximize boxes, you cancompile and run your application. The minimize and maximizebuttons appear on the title bar


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File Types in Project

dsw :Workspace file

.dsp :Project file

.clw :ClassWizard file

.ncb :No Compile Browser file(Contains details used byClassview & Classwizard Toolbar)

.opt :Options file(Stores cusomized workspace display)

.cpp :C++ source file (Implementation Code)

.h :C++ header file(definition & class declaration code)

.rc :Resource Script file(details of resources)

.rc2 :Resource Script file(used to include resourcesin to otherprojects)


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Understanding the Components of a Dialog-Based Application

Dialog applications are much simpler than SDI and MDIapplications. Create one called FirstDialog , with an About box,no Help, 3D controls, no automation, ActiveX control support,no sockets, source file comments, and MFC as a shared DLL. Inother words, accept all the default options.

Three classes have been created for you for the applicationcalled FirstDialog :

CAboutDlg, a dialog class for the About dialog box

CFirstDialogApp, a CWinApp class for the entire application

CFirstDialogDlg, a dialog class for the entire application.

All the familiar Windows controls are available for dialog boxes

Static text . Not really a control, this is used to label othercontrols such as edit boxes.

Edit box . Single line or multi line, this is a place for users totype strings or numbers as input to the program. Read-onlyedit boxes are used to display text.

Button . Every dialog box starts with OK and Cancel buttons,but you can add as many of your own as you want.

Check box . You use this control to set options on or off; eachoption can be selected or deselected independently.

Radio button . You use this to select only one of a number of related options. Selecting one button deselects the rest.

List box . You use this box type to select one item from a listhard coded into the dialog box or filled in by the program asthe dialog box is created. The user cannot type in the selectionarea.


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Combo box . A combination of an edit box and a list box, thiscontrol enables users to select from a list or type theirresponse, if the one they want isn't on the list.

The data types that go with each control type

Edit box. Usually a string but also can be other data types,including int, float, and long

Check box . int

Radio button . int

List box. String

Combo box. String

Scrollbar . int

Access Values from a Control

To access values from control in VC++ you have to createMember Variable ( It gives bound values connectivity tocontrol )

OR

You have to create Constructer derived from ControlClasses( to access values from control dynamically &unbound )

To create Member Variable (bound) use following the steps :

Select a control & Right Click and select Class Wizard or pressCTRL + W.

Then Select Member Variables Tag


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Then choose its type or category from given options


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Data Validation


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You can give the limitations to the variables

To store the Values in variable

Use UpdateData( ) function to clear or store the values inmember variable.

To clear or restore the previous value use UpdateData( 0 )

To store the value for display in control use

UpdateData( 1 ).

Creating Constructer Variable :


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You have to create reference from base class of the relatedcontrol

CONTROL BASE CLASS

Buttons CButton

List boxes CListBox

Edit controls CEdit

Combo boxes CComboBox

Scroll bars CScrollBar

Static controls CStatic

Way of Creation

CEdit* ed = (CEdit*)GetDlgItem(IDC_EDIT1);

Where GetDlgItem() contains the name of Control;

CEdit is the base class for EDIT BOX control & ed is theconstructer for the control

ed will represent all the properties supported by the EDITBOX

To add the local variable/functions

To create local variable for your project choose following steps

Right click on the dlg class from class view

Select Add Member Variable or Add Member Function option(all the type of variable or function is same as C++)


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File Types in Project

dsw : Workspace file

.dsp :Project file


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.clw :ClassWizard file

.ncb :No Compile Browser file(Contains details used byClassview & Classwizard Toolbar)

.opt :Options file(Stores cusomized workspace display)

.cpp :C++ source file (Implementation Code)

.h :C++ header file(definition & class declaration code)

A Single Document Interface Application

An SDI application has menus that the user uses to open onedocument at a time and work with that document. This sectionpresents the code that is generated when you create an SDIapplication with no database or compound document support,with a toolbar, a status bar, Help, 3D controls, source filecomments, and with the MFC library as a shared DLL in otherwords when you accept all the AppWizard defaults after Step1.

Five classes have been created for you. For the applicationFirstSDI, they are as follows:


CFirstSDIApp, a CWinApp class for the entire application

CFirstSDIDoc, a document class

CFirstSDIView, a view class

CMainFrame, a frame class

In Last Step (6) you can select the base class for your SDIapplication.


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SDI Application Run time view


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Understanding a Multiple Document Interface Application

A multiple document interface application also has menus, andit enables the user to have more than one document open atonce. This section presents the code that is generated whenyou choose an MDI application with no database or compounddocument support, but instead with a toolbar, a status bar,Help, 3D controls, source file comments, and the MFC libraryas a shared DLL. As with the SDI application, these are thedefaults after Step 1. The focus here is on what differs fromthe SDI application in the previous section.Six classes havebeen created for you :


CFirstMDIApp, a CWinApp class for the entire application

CFirstMDIDoc, a document class

CFirstMDIView, a view class


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CMainFrame, a frame class

CChildFrame, a child frame class

MDI Application Design view

MDI Application Run time view


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Database Connectivity

With Simple Dialog Box

Create ODBC DSN from Control Panel for your Table

First include Header file named : afxdb.h in project.

Then create Member Variable with type of CDatabase (db)formain database (eg. *.mdb);

After creating database, create Member Variable with type of

CRecordset(rs)

To Connect Database with DSN created by ODBC

db.OpenEx("DSN= DSN name ;UID= User name ");

Connect the Recordset (rs) with Database


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rs.m_pDatabase=&db;

To Connect the Particular Table

rs.Open(CRecordset::snapshot,"select * from tablename ");

^ Recordset type

To get the field value of the field

rs .GetFieldValue( fieldname ",variable);

To get First Record : rs .MoveFirst();

To get Next Record : rs .MoveNext();

To get Prev Record : rs .MovePrev();

To get Last Record : rs .MoveLast();

To Add the Record :

CString query;

query = insert into tablename +

fieldValue +

db.ExecuteSQL(query);

rs.Requery();

To delete the record

CString query;

query="delete from table name where

field name = "+ field value +"'";


rs.Requery();

To Edit the record :


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CString query;

query="update table name set field name ='"+ field value +";


rs.Requery();

Other functions :

IsEOF, IsBOF etc.


o With SDI Application

While Creating Application :

1. In Step 2 Select Database View without file support option

2. Click on Data Source Button & Select ODBC

1. Give particular DSN

2. Then Select Particular Table from dialog box

In Step 4 Deselect Printing & print preview option

VC++ automatically creates the public variable with databaseutility named : m_pSet

Take Edit Boxes as per your databases field

Create Member Variables for each edit box.

In the Member Variable Name Combo box There isthe list of Field variables per your

database fields

Select appropriate Field variable for each edit box


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e.g. : m_pSet-> m_Fieldname for an edit box

variable

It will display the record value in appropriate edit box. (run

time) You can move the record from toolbar or menu by selectingappropriate option

To Add Record :

m_pSet->AddNew();

UpdateData(1);

m_pSet->Update();


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To Edit Record :

m_pSet->Edit();

UpdateData(1);

m_pSet->Update();

To Delete Record :

m_pSet->Delete();

UpdateData(1);

Other functions :

IsEOF, IsBOF etc.


With OLEDB

In Step 2 Select Database view without file support

Then Click on the DataSource Button

Select OLEDB option & select ODBC provider & give DSN orbuild connection string

Then click OK & select the required table.

It will automatically create the variable named m_pSet

Use all the commands( of ODBC connectivity ) to utilize thedatabase.

With DAO

[Window Title]

Reserved Battery Level


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[Main Instruction]

Plug in or find another power source

[Content]

Your battery power is low (7%). If you don't plug in your computersoon, it will hibernate automatically.

#include #include #include

#include

Create CFile object eg. :

CFile f;

Then use following syntax :

f.Open(filename",CFile::modeCreate|CFile::modeWrite );

To Write the Data into file use following :

CString sz =It the CFile Text;

f.Write(sz, strlen(sz));

f.Close();

CArchive

Archive is associated with a file and permits the bufferedwriting and reading of data to and from storage

You must create a CFile object before you can create aCArchive object.

The archives load/store status is compatible with the filesopen mode. You are limited to one active archive per file.


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When you construct a CArchive object, you attach it to anobject of class CFile (or a derived class) that represents anopen file.

CArchive also supports programming with the MFC WindowsSockets classes CSocket and CSocketFile. The IsBufferEmptymember function supports that usage

Example :

CFile myFile(Note.txt", CFile::modeCreate |CFile::modeWrite);

CArchive ar(&myFile, CArchive::store);

ar.WriteString( This from Archive" );

// Flush all of the data to the file :

ar.Flush();

ar.Close();

Exception Handling

CException CException is the base class for all exceptions.

Some derived classes :

CMemoryException Out-of-memory exception

CNotSupportedException Request for an unsupportedoperation

CArchiveException Archive-specific exception

CFileException File-specific exception

CDBException Database exception (based on ODBC)

CDaoException Data access object exception (that is,exception conditions arising for DAO classes)

CInternetException Internet exception (for Internet classes).


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These exceptions are intended to be used with the

TRY, CATCH, AND_CATCH, and END_CATCH macros

Simple Example

CFile tmpFile;

CFileException ex;

if (! tmpFile.Open("\\Tmp\\temp.txt", CFile::modeRead, &ex))

{

TCHAR tmp[255];

CString str;

ex.GetErrorMessage(tmp, 255);

str = The data file could not be opened because : ";

strr += tmp;

MessageBox(str);

}

else

tmpFile.Close();

TRY

Use this macro to set up a TRY block.

A TRY block identifies a block of code that might throwexceptions.

Those exceptions are handled in the following CATCH andAND_CATCH blocks.

CATCH

Use this macro to define a block of code that catches the firstexception type thrown in the preceding TRY block.


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CATCH ( exception_class , exception_object_pointer_name )

Where

exception_class : Specifies the exception type to test for.

exception_object_pointer_name : Specifies a name for anexception-object pointer that will be created by the macro.

You can use the pointer name to access the exception objectwithin the CATCH block.

Example :

CFile* pFile = NULL;

TRY

{

pFile = new CFile("\\Too\\temp.txt", CFile::modeRead);

}

CATCH (CFileException, Ex)

{

Ex->ReportError(MB_OK,0);

}

END_CATCH

AND_CATCH

AND_CATCH( exception_class, exception_object_pointer_name )

Where :

exception_classSpecifies the exception type to test for.

exception_object_pointer_name


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A name for an exception-object pointer that will be created bythe macro. You can use the pointer name to access theexception object within the AND_CATCH block.

END_CATCH

Marks the end of the last CATCH or AND_CATCH block.

spawnl(var,exe file,arg1,path,NULL);

This function is used to start new process or application

_P_OVERLAY

Overlays calling process with new process,destroying the callingprocess

_P_WAIT

Suspends calling thread until execution of new process iscomplete

_P_NOWAIT

Continues to execute calling process concurrently with newprocess

_P_DETACH

Continues to execute the calling process; new process is run inthe background with no access to the console or keyboard.

For Example to start doc file in MS Word

_spawnl(_P_NOWAIT,C:windows\\notepad.exe,*.doc,C:\\temp.txt,NULL)


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CFileDialog

#include

The CFileDialog class encapsulates the Windows common file dialog box.Common file dialog boxes provide an easy way to implement File Open and


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File Save As dialog boxes (as well as other file-selection dialog boxes) in amanner consistent with Windows standards.

CFileDialog( BOOL bOpenFileDialog , LPCTSTR lpszDefExt = NULL,LPCTSTR lpszFileName = NULL, DWORD dwFlags =

OFN_HIDEREADONLY | OFN_OVERWRITEPROMPT, LPCTSTR lpszFilter =NULL, CWnd* pParentWnd = NULL );

Where :

bOpenFileDialog

Set to TRUE to construct a File Open dialog box or FALSE to construct a FileSave As dialog box.

lpszDefExt

The default filename extension. If the user does not include an extension inthe Filename edit box, the extension specified by lpszDefExt is automaticallyappended to the filename. If this parameter is NULL , no file extension isappended.

lpszFileName

The initial filename that appears in the filename edit box. If NULL , nofilename initially appears.

dwFlags

A combination of one or more flags that allow you to customize the dialogbox.

lpszFilter

A series of string pairs that specify filters you can apply to the file. If youspecify file filters, only selected files will appear in the Files list box. See theRemarks section for more information on how to work with file filters.

pParentWnd

A pointer to the file dialog-box objects parent or owner window.

Example :

CFileDialog FDlg(1,"htm","hello.htm",1,"Html Files (*.htm)|*.htm|All Files |*.*||");


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FDlg.DoModal();

CFontDialog The CFontDialog class allows you to incorporate a font-selection dialog boxinto your application. A CFontDialog object is a dialog box with a list of fonts that are currently installed in the system. The user can select aparticular font from the list, and this selection is then reported back to theapplication.


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Once a CFontDialog object has been constructed, you can use the m_cf structure to initialize the values or states of controls in the dialog box. Them_cf structure is of type CHOOSEFONT.

CFontDialog( LPLOGFONT lplfInitial = NULL, DWORD dwFlags =

CF_EFFECTS | CF_SCREENFONTS, CDC* pdcPrinter = NULL, CWnd* pParentWnd = NULL );

Where :

lplfInitial

A pointer to a LOGFONT data structure that allows you to set some of thefonts characteristics.

dwFlags

Specifies one or more choose-font flags. One or more preset values can becombined using the bitwise OR operator.

pdcPrinter

A pointer to a printer-device context. If supplied, this parameter points to aprinter-device context for the printer on which the fonts are to be selected.

Example :

Show Font Dialog with default settings :CFontDialog dlg;

dlg.DoModal();

Sub Functions :

DoModal Displays the dialog and allows the user to make a selection.

GetCurrentFont Retrieves the name of the currently selected font.

GetFaceName Returns the face name of the selected font.

GetStyleName Returns the style name of the selected font.

GetSize Returns the point size of the selected font.

GetColor Returns the color of the selected font.


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GetWeight Returns the weight of the selected font.

IsStrikeOut Determines whether the font is displayed with strikeout.

IsUnderline Determines whether the font is underlined.

IsBold Determines whether the font is bold.

IsItalic Determines whether the font is italic.

CColorDialog

The CColorDialog class allows you to incorporate a color-selection dialogbox into your application. A CColorDialog object is a dialog box with a list of colors that are defined for the display system. The user can select or createa particular color from the list, which is then reported back to the applicationwhen the dialog box exits.


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Once the dialog box has been constructed, you can set or modify any valuesin the m_cc structure to initialize the values of the dialog boxs controls. Them_cc structure is of type CHOOSECOLOR.

CColorDialog( COLORREF clrInit = 0, DWORD dwFlags = 0, CWnd*

pParentWnd = NULL );

Where :

clrInit

The default color selection. If no value is specified, the default is RGB(0,0,0)(black).

dwFlags

A set of flags that customize the function and appearance of the dialog box.pParentWnd

A pointer to the dialog boxs parent or owner window.

Example :

CColorDialog Coldlg; Color dialog with all the default settings.

Coldlg.DoModal();

Sub Functions :

DoModal Displays a color dialog box and allows the user to make aselection.

GetColor Returns a COLORREF structure containing the values of theselected color.

GetSavedCustomColors Retrieves custom colors created by the user.

SetCurrentColor Forces the current color selection to the specified color.


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CPageSetupDialog

The CPageSetupDialog class encapsulates the services provided by theWindows common OLE Page Setup dialog box with additional support forsetting and modifying print margins. This class is designed to take the placeof the Print Setup dialog box.

To use a CPageSetupDialog object, first create the object using theCPageSetupDialog constructor. Once the dialog box has been constructed,

you can set or modify any values in the m_psd data member to initialize thevalues of the dialog box's controls. The m_psd structure is of typePAGESETUPDLG .

Example :

CPageSetupDialog Psdlg;


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Psdlg.DoModal();

Attributes & Sub Functions :

m_psd A structure used to customize a CPageSetupDialog

object.DoModal Displays the dialog box and allows the user make a selection.

CreatePrinterDC Creates a device context for printing.

GetDeviceName Returns the device name of the printer.

GetDevMode Returns the current DEVMODE of the printer.

GetDriverName Returns the driver used by the printer.

GetMargins Returns the current margin settings of the printer.

GetPortName Returns the output port name.

GetPaperSize Returns the paper size of the printer.


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CPrintDialog

The CPrintDialog class encapsulates the services provided by the Windowscommon dialog box for printing. Common print dialog boxes provide an easyway to implement Print and Print Setup dialog boxes in a manner consistentwith Windows standards.

To use a CPrintDialog object, first create the object using the CPrintDialogconstructor. Once the dialog box has been constructed, you can set ormodify any values in the m_pd structure to initialize the values of the dialogboxs controls. The m_pd structure is of type PRINTDLG.


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Example :

CPrintDialog PrtDlg(0); or PrtDlg(1);

PrtDlg.DoModal();

Sub Functions

CreatePrinterDC Creates a printer device context without displaying thePrint dialog box

DoModal Displays the dialog box and allows the user to make a selection.

GetCopies Retrieves the number of copies requested.

GetDefaults Retrieves device defaults without displaying a dialog box.

GetDeviceName Retrieves the name of the currently selected printerdevice.

GetDevMode Retrieves the DEVMODE structure.

GetDriverName Retrieves the name of the currently selected printer driver.

GetFromPage Retrieves the starting page of the print range.

GetToPage Retrieves the ending page of the print range.

GetPortName Retrieves the name of the currently selected printer port.

GetPrinterDC Retrieves a handle to the printer device context.

PrintAll Determines whether to print all pages of the document.

PrintCollate Determines whether collated copies are requested.

PrintRange Determines whether to print only a specified range of pages.

PrintSelection Determines whether to print only the currently selecteditems.


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CFileFind The MFC class CFileFind performs local file searches and is the base classfor CGopherFileFind and CFtpFileFind , which perform Internet filesearches. CFileFind includes member functions that begin a search, locatea file, and return the title, name, or path of the file. For Internet searches,the member function GetFileURL returns the files URL.

Example :

CFileFind findexe;

BOOL stat = findexe.FindFile("*.exe");

while (stat)

{

stat = findexe.FindNextFile();


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MessageBox(findexe.GetFileName());

}

_chmod, _wchmod ( include , )

Change the file-permission settings.

_chmod( const char *filename , int pmode );

Where :

filename Name of existing file

pmode Permission setting for file

_S_IWRITE Writing permitted

_S_IREAD Reading permitted

_S_IREAD | _S_IWRITE Reading and writing permitted

_access, _waccess ( include , )

Determine file-access permission.

int _access( const char * path , int mode );

Where :

path File or directory path

mode Permission setting

mode ValueChecks File For

00 Existence only

02 Write permission

04 Read permission

06 Read and write permission

To Get or Set the Current Directory


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TCHAR cur[MAX_PATH]; used to get system buffer path

MAX_PATH is system variable to access maximum path

SetCurrentDirectory ("C:\\windows");

GetCurrentDirectory (MAX_PATH,cur);

MessageBox(cur);

To get the SIZE of the file

CFile::GetStatus

CFileStatus st;

CFile::GetStatus("f:\\drk.zip",st);

CString str;

str.Format("%ld",st.m_size);

MessageBox(str);


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Building Applications Using VC