addixdlg.cpp

一个作的很好的dao数据库开发

// AddIxDlg.cpp : implementation file for dialog that lets user add
// indexes to tabledefs
//
// This is a part of the Microsoft Foundation Classes C++ library.
// Copyright (C) 1992-1998 Microsoft Corporation
// All rights reserved.
//
// This source code is only intended as a supplement to the
// Microsoft Foundation Classes Reference and related
// electronic documentation provided with the library.
// See these sources for detailed information regarding the
// Microsoft Foundation Classes product.

#include "stdafx.h"
#include "DAOTable.h"
#include "listctrl.h"
#include "AddIxDlg.h"
#include "tabledef.h"
#include "index.h"
#include "field.h"

#ifdef _DEBUG
#define new DEBUG_NEW
#undef THIS_FILE
static char THIS_FILE[] = __FILE__;
#endif

/////////////////////////////////////////////////////////////////////////////
// CAddIndexDlg dialog

// default constructor
CAddIndexDlg::CAddIndexDlg(CWnd* pParent /*=NULL*/)
	: CDialog(CAddIndexDlg::IDD, pParent)
{
	// call centralized initialization function
	initializer();
}

// constructor that will generally be used to create
// the dialog--parameters are needed to do any useful
// database operations
//
// IN: pDatabase--pointer to the open database object
// IN: strTableName--name of the tabledef to which to add indexes
// IN: pParent--pointer to parent of this dialog
CAddIndexDlg::CAddIndexDlg(CDaoDatabase *pDatabase,
						   CString strTableName,
						   CWnd* pParent)
	: CDialog(CAddIndexDlg::IDD, pParent)

{
	// call centralized initialization function
	initializer();

	// initiliaze and set members to incoming parameters
	m_pTableDef = NULL;
	m_pDatabase = pDatabase;
	m_strTableName = strTableName;
}

// centralized initialization function
void CAddIndexDlg::initializer()
{
	// initialize the index info struct
	indexInitializer();

	// by default, DDV functions are called in the DoDataExchange
	m_bCheckDDV = TRUE;

	// collection index starts at zero
	m_nIndexIndex = 0;
}

// initialize the index info struct members and equivalent
// class members
void CAddIndexDlg::indexInitializer()
{
	//{{AFX_DATA_INIT(CAddIndexDlg)
	//}}AFX_DATA_INIT

	// index info struct
	m_II.m_strName = _T("");
	m_II.m_bPrimary = FALSE;
	m_II.m_bIgnoreNulls = FALSE;
	m_II.m_bRequired = FALSE;
	m_II.m_bUnique = FALSE;

	// clear out the list of fields in case it is not empty--
	// this is an array of index field info structs that are
	// the fields that make up the index
	if (m_II.m_pFieldInfos != NULL)
	{
		delete [] m_II.m_pFieldInfos;
		m_II.m_pFieldInfos = NULL;
		m_II.m_nFields = 0;
	}
}


void CAddIndexDlg::DoDataExchange(CDataExchange* pDX)
{
	CDialog::DoDataExchange(pDX);
	//{{AFX_DATA_MAP(CAddIndexDlg)
	DDX_Control(pDX, IDC_UNIQUE, m_UniqueControl);
	DDX_Control(pDX, IDC_REQUIRED, m_RequiredControl);
	DDX_Control(pDX, IDC_IGNORE_NULLS, m_IgnoreNullControl);
	DDX_Control(pDX, IDC_PRIMARY, m_PrimaryControl);
	DDX_Text(pDX, IDC_TABLE_NAME, m_strTableName);
	//}}AFX_DATA_MAP

	// these have to be moved outside of the wizard block
	// since they directly map to members of the index info
	// struct
	DDX_Check(pDX, IDC_PRIMARY, m_II.m_bPrimary);
	DDX_Check(pDX, IDC_IGNORE_NULLS, m_II.m_bIgnoreNulls);
	DDX_Check(pDX, IDC_REQUIRED, m_II.m_bRequired);
	DDX_Check(pDX, IDC_UNIQUE, m_II.m_bUnique);

	DDX_Text(pDX, IDC_INDEX_NAME, m_II.m_strName);

	// moved outside of wizard block since DDV is used
	DDX_Control(pDX, IDC_FIELD_LIST, m_FieldListListControl);
	// conditionally check validity of input
	if (m_bCheckDDV)
	{
		// user must select at least one field for the index
		DDV_NoSel(pDX, &m_FieldListListControl);
	}
}


// check if a field selection was made--at least one field must be
// selected.  Selected fields contain a non-null string in their
// first sub-item (i.e. "ascending" or "descending")
void CAddIndexDlg::DDV_NoSel(CDataExchange* pDX, CListCtrl *theControl)
{
	// only process if transferring to member from control.  If
	// no selection has been made, this constitutes an error condition
	if (pDX->m_bSaveAndValidate)
	{
		// check if any items selected--initialize a counter
		int count = 0;

		// for as many items in the list view, keep checking until one is
		// found that has been selected
		for (int i = 0; (count == 0) && (i < theControl->GetItemCount()); i++)
		{
			// the contents of the subitem determines selection state
			if (theControl->GetItemText(i, 1) != _T(""))
			{
				// up the count by one to end the loop
				count += 1;
			}
		}

		// if no selection, then error!
		if (count == 0)
		{
			AfxMessageBox(_T("You must select a field."), MB_ICONEXCLAMATION);
			pDX->m_hWndLastControl = theControl->m_hWnd;
			pDX->Fail();
		}
	}
}

BEGIN_MESSAGE_MAP(CAddIndexDlg, CDialog)
	//{{AFX_MSG_MAP(CAddIndexDlg)
	ON_BN_CLICKED(IDOK, OnDone)
	ON_WM_CLOSE()
	ON_BN_CLICKED(IDC_ADD_INDEX, OnAddIndex)
	ON_BN_CLICKED(IDC_DELETE_INDEX, OnDeleteIndex)
	ON_BN_CLICKED(IDC_NEXT_INDEX, OnNextIndex)
	ON_BN_CLICKED(IDC_PREVIOUS_INDEX, OnPreviousIndex)
	//}}AFX_MSG_MAP
END_MESSAGE_MAP()

/////////////////////////////////////////////////////////////////////////////
// CAddIndexDlg message handlers

BOOL CAddIndexDlg::OnInitDialog()
{
	CDialog::OnInitDialog();

	// do some initialization for the list control
	//
	// set style so that list view will show its selections even when the
	// control loses focus
	LONG style = ::GetWindowLong(m_FieldListListControl.m_hWnd,GWL_STYLE);
	::SetWindowLong(m_FieldListListControl.m_hWnd, GWL_STYLE,style | LVS_SHOWSELALWAYS);

	// get size of control to help set the column widths
	CRect controlRect;
	m_FieldListListControl.GetClientRect(controlRect);
	//
	// get width of control, width of potential scrollbar, width needed for sub-item
	// string
	int controlWidth = controlRect.Width();
	int scrollThumbWidth = ::GetSystemMetrics(SM_CXHTHUMB);
	int strWidth = m_FieldListListControl.GetStringWidth(_T("descending"));
	// factor the border width into the string width
	strWidth += 12 * ::GetSystemMetrics(SM_CXBORDER);
	//
	// set up columns--1st leaves room for second and scroll bar
	m_FieldListListControl.InsertColumn(1, _T("Field"), LVCFMT_LEFT,
							controlWidth - scrollThumbWidth - strWidth, 1);
	m_FieldListListControl.InsertColumn(2, _T("Sort"), LVCFMT_LEFT, strWidth + scrollThumbWidth, 2);

	// open the tabledef if possible
	if(openTableDef(m_pDatabase, &m_pTableDef, m_strTableName))
	{
		// now populate the list of fields list control with fields
		populateFieldList();

		// get the information for the first index in the collection of indexes
		// last parameter specifies no error reporting--run silently since
		// there may be no indexes yet
		if(getIndexInfo(m_pTableDef, &m_II, m_nIndexIndex, FALSE))
		{
			// most properties are readonly once an index is in a collection
			disableControlsForExisting(TRUE);

			// list control should reflect the fields in the index
			setFieldListSelections();

			UpdateData(FALSE);
		}
	}

	// set focus to index name control unless there is some problem (unlikely)
	CEdit *pEdit = (CEdit *)GetDlgItem(IDC_INDEX_NAME);
	if (pEdit != NULL)
	{
		pEdit->SetFocus();
		return FALSE;
	}
	else
		return TRUE;  // return TRUE unless you set the focus to a control
}

// user selected to move to the next index in the collection
void CAddIndexDlg::OnNextIndex()
{
	// get values from control -- no validity checking
	m_bCheckDDV = FALSE;    // turn validity checking off
	UpdateData(TRUE);
	m_bCheckDDV = TRUE;     // turn checking back on--don't forget this!

	// action depends on if this is an existing index or not
	// if this is a new index (based on name) see if user wants to save it
	// or not--if not, then try to move to next index
	if ((m_II.m_strName != _T("")) && (!IsExistentIndex(m_pTableDef, m_II.m_strName)))
		if (IDYES != AfxMessageBox(_T("Current index will be ignored unless added.  Continue anyway?"),
								MB_YESNO))
			return;

	// can only move next if there is a item at the current index in the
	// collection--else you keep indexing into unused parts of the index.
	// So, check for existence of current indexed item and only increment
	// the index if there is an item (no error reporting)
	if (getIndexInfo(m_pTableDef, &m_II, m_nIndexIndex, FALSE))
		// move to next field index
		m_nIndexIndex += 1;

	// get the information for the next index if possible--
	// last parameter indicates no failure reporting
	if (getIndexInfo(m_pTableDef, &m_II, m_nIndexIndex, FALSE))
	{
		// list control should be cleared and then set to new values for this index
		setFieldListSelections(FALSE);

		// most properties are readonly once a field is in a collection
		disableControlsForExisting(TRUE);
	}
	else
	{
		// initialize field property values for new field
		indexInitializer();

		// list box should be cleared
		setFieldListSelections(TRUE);

		// new field have read/write properties
		disableControlsForExisting(FALSE);
	}

	UpdateData(FALSE);

	// set focus to name of field edit box
	CEdit *pEdit = (CEdit *)GetDlgItem(IDC_INDEX_NAME);
	pEdit->SetFocus();
}

// user selected to more to the previous index in the collection
void CAddIndexDlg::OnPreviousIndex()
{
	// can't go previous if at 0th index
	if (m_nIndexIndex >= 1)
	{
		// by default, we will move previous
		int retCode = IDYES;

		// if user has entered an index name, then warn them they will lose
		// it if it is not explicitly added--we don't want to do an auto-add
		// since user may have entered name without meaning to add another index
		//
		// see if there is a index name specified
		CString name;
		CEdit *pEdit = (CEdit *)GetDlgItem(IDC_INDEX_NAME);
		pEdit->GetWindowText(name);
		// if there is a name, then warn the user
		if (name.GetLength() != 0)
		{
			// only an issue if this is not an existing index
			if (!IsExistentIndex(m_pTableDef, name))
				retCode = AfxMessageBox(_T("Current index will be ignored unless added.  Continue anyway?"),
									MB_YESNO);
		}