Loading and Saving Annotations Using Databases (C++ 5.0 and later)

To start a project and add code that demonstrates adding annotation objects to or deleting annotation objects from the BLOB field of a database file:

First create a database file (in this case, named D:\TEMP\DB1.MDB) with one table named Images and with the fields listed below:

Field Name	Type
Image	Binary
Size	Number

Start a new project as follows:

Run Microsoft Visual Studio, select the File New Project, and do the following:
1. Expand Visual C++ tree, if it is not already expanded.
2. Select MFC from the sub tree.
3. Select MFC Application from the right window.
4. In the Project name text box, specify AnnBlob.
5. In the Location text box, specify the path of the project.
6. Click the OK button.
In the overview window Just click Next.
In the Application Type step dialog box, do the following:
1. Select Dialog based.
2. Use MFC in a shared DLL.
3. Click the Next button.
In the Step 2 of 4 dialog box, do the following:
1. Ensure that About Box is selected.
2. Ensure that System Menu is selected.
3. Click the Next button.
In the Step 3 of 4 dialog box, just click Finish:
Add #include statements to your program so you can access the LEAD C++ Class Library constants and classes:
1. In the Project Workspace, click the Solution Explorer tab.
2. Double-click the AnnBlob Project folder to open it.
3. Double-click the Header Files folder to open it.
4. Double-click the StdAfx.h file to edit it.
Add the following lines to the end of the file (keep in mind, you may have to change the path to where the header files reside):
```
#include "..\..\..\..\..\include\ClassLib\ltWrappr.h" 
```
Add a Button control to the main window as follows:
1. In the Project Workspace, click the ResourceView tab.
2. Double-click the AnnBlob.rc folder to open it.
3. Double-click the Dialog folder to open it.
4. Double-click IDD_IMAGEBLOB_DIALOG to design the form.
5. Select the TODO... text control; then press the Delete key to delete it.
6. Click the Static Text control icon, add a control to the dialog, then size and position the control as you want it to appear at run time.
Add #import statements to your program so you can access the Microsoft ActiveX Data Object 2.6 Library:
1. In the Project Workspace, click the Solution Explorer tab.
2. Double-click the AnnBlob folder to open it.
3. Double-click the Header Files folder to open it.
4. Double-click the StdAfx.h file to edit it.
Add the following lines to the end of the file (keep in mind, you may have to change the path to where the .tlb files reside):
```
#import <C:\\Windows\\system32\\msado26.tlb> rename("EOF", "ADOEOF")   
using namespace ADODB; 
```

Click the Resource View tab. On the View menu, select ToolBox, and then add six command buttons to your form and name them as follows:

ID	Caption
IDC_CONNECT	&Connect To Database
IDC_DISCONNECT	&Disconnect From Database
IDC_ADDRECORD	&Add Record
IDC_DELETERECORD	D&elete Record
IDC_MOVENEXT	Move &Next
IDC_MOVEPREVIOUS	Move &Previous

Save the resource file.

Do the following to add m_btnAddRecord to the CAnnBlobDlg class and link the variable to the CButton control using dynamic data exchange:
1. Open AnnBlob.rc and Double-click on IDD_IMAGEBLOB_DIALOG.
2. Right-click on the Add Record button, and choose Add Variable.
3. Specify m_btnAddRecord as the variable name, and Control as the category.
4. Click Finish to close the dialog box.

Repeat step 11 for the other buttons, using the following variable names:

ID	Member Variable Name
IDC_MOVEPREVIOUS	m_btnMovePrevious
IDC_MOVENEXT	m_btnMoveNext
IDC_DISCONNECT	m_btnDisconnect
IDC_DELETERECORD	m_btnDeleteRecord
IDC_CONNECT	m_btnConnect

Add the following Member Variables to the CAnnBlobDlg class:

Type Member

_ConnectionPtr m_pConnection

_RecordsetPtr m_pRecordset

LAnnotationWindow m_LAnnoWnd
Go to the OnInitDialog() function as follows:
1. From view menu, select Class view.
2. In the Project Workspace, click the ClassView tab.
3. Double-click the AnnBlob folder to open it.
4. Click on the CAnnBlobDlg class.
5. Double-click the OnInitDialog()function in the lower window to edit it.

Type	Member
_ConnectionPtr	m_pConnection
_RecordsetPtr	m_pRecordset
LAnnotationWindow	m_LAnnoWnd

Edit the OnInitDialog() function to add the following code after the line that says //TODO: Add extra initialization here:

LBase::LoadLibraries(LT_KRN); 
LBase::LoadLibraries(LT_DIS); 
LBase::LoadLibraries(LT_FIL); 
LBase::LoadLibraries(LT_ANN); 
L_TCHAR * pszLicenseFile = L"Replace this with the path to the LEADTOOLS license file"; 
L_TCHAR * pszDeveloperKey = L"Replace this with your developer key"; 
LSettings::SetLicenseFile(pszLicenseFile, pszDeveloperKey); 
RECT rc; 
 
GetDlgItem(IDC_STATIC)->GetWindowRect(&rc); 
ScreenToClient(&rc); 
HWND hWnd = m_LAnnoWnd.CreateWnd(this->GetSafeHwnd(),0, WS_VISIBLE|L_BS_CENTER| L_BS_PROCESSKEYBOARD, rc.left, rc.top, rc.right, rc.bottom); 
 
if (!m_LAnnoWnd.GetToolBar().IsCreated()) 
   m_LAnnoWnd.GetToolBar().Create(hWnd, NULL, ANNTOOLALIGN_RIGHT | ANNTOOLALIGN_TOP, TRUE, NULL, NULL); 
 
m_LAnnoWnd.EnableAutoScroll(TRUE); 
m_LAnnoWnd.SetFileName (MAKE_IMAGE_PATH(TEXT("image1.cmp"))); 
int nRet = m_LAnnoWnd.Load (0,ORDER_BGR, 1); 
HRESULT hr; 
CoInitialize(NULL); 
hr = m_pConnection.CreateInstance(__uuidof( Connection)); 
m_pRecordset.CreateInstance(__uuidof(Recordset)); 
m_btnMoveNext.EnableWindow(FALSE); 
m_btnMovePrevious.EnableWindow(FALSE); 
m_btnAddRecord.EnableWindow(FALSE); 
m_btnDeleteRecord.EnableWindow(FALSE);

Do the following to add an event handler to the Connect To Database button:

Open AnnBlob.rc and Double-click on IDD_IMAGEBLOB_DIALOG.
Right-click on the Connect To Database button, and choose Add Event Handler.
From the Message Type List, choose BN_CLICKED.