Først: Det hele starter i Hovedformen, «TForm1», alle menyfunksjoner gjør det, og så jumper programmet i de fleste tilfelle til en funksjon i «DocPage» klassen. Det eneste som gjøres her er å opprette en adressepeker til neste funksjon:

// --------------------- Display Image Properties ---------------

	void __fastcall TForm1::menu_PROPERTIES_Click(TObject *Sender)         // 19
{
	 TTabItem   *myTabItemPtr;

	 // Get a pointer to active tab
	 myTabItemPtr = TabControl1->ActiveTab;

	 // Type cast to class DocPage and
	 // let DocPage do the job
	 ((DocPage *) myTabItemPtr)->ImageProperties();
}

De meste av info finnes i bitmap’en, «TBitmap», og hvordan du henter opp denne er egentlig forklart i dokumentasjonen fra Embarcadero.

// --------------------------------------------------------------------------
//  				Image Properties
// --------------------------------------------------------------------------
void __fastcall DocPage::ImageProperties()
{
	try
	{
		TForm6 *dlgProperties =  new TForm6(Application);

		dlgProperties->Image1->Bitmap = Image1->Bitmap;
		dlgProperties->Caption = _T("Image Properties");

		// Pixelformat
		TPixelFormat myPixelformat = Image1->Bitmap->PixelFormat;
		UnicodeString strPixelformat(PixelFormatToString(myPixelformat));
		dlgProperties->Edit1->Text = strPixelformat;

		// Bitmap Scale
		float BitmapScale = Image1->Bitmap->BitmapScale;
		UnicodeString strBitmapScale(BitmapScale);
		dlgProperties->Edit2->Text = strBitmapScale;

		// Bytes per line
		int BytesPerLine = Image1->Bitmap->BytesPerLine;
		UnicodeString strBytesPerLine(BytesPerLine);
		dlgProperties->Edit3->Text = strBytesPerLine;

		// Bytes per pixel
		int BytesPerPixel = Image1->Bitmap->BytesPerPixel;
		UnicodeString strBytesPerPixel(BytesPerPixel);
		dlgProperties->Edit4->Text = strBytesPerPixel;

		// Bitmap Height
		int Height = Image1->Bitmap->Height;
		UnicodeString strHeight(Height);
		dlgProperties->Edit5->Text = strHeight;

		// Bitmap Width
		int Width = Image1->Bitmap->Width;
		UnicodeString strWidth(Width);
		dlgProperties->Edit6->Text = strWidth;
		// -----------------------------------------------------------------
		// DisplayCount
		iDisplayCount = Screen->DisplayCount;
		UnicodeString strDisplayCount(iDisplayCount);
		dlgProperties->Edit7->Text = strDisplayCount;

		// Desktop Width i pixels (might be for instance dual screen)
		iDesktopWidthInPixels = Screen->DesktopWidth;
		UnicodeString strDesktopWidth(iDesktopWidthInPixels);
		dlgProperties->Edit8->Text = strDesktopWidth;

		// Desktop Height i pixels
		iDesktopHeightInPixels = Screen->DesktopHeight;
		UnicodeString strDesktopHeight(iDesktopHeightInPixels);
		dlgProperties->Edit9->Text = strDesktopHeight;

		// Screen Width in pixels
		iScreenWidthInPixels = Screen->Width;
		UnicodeString strScreenWidth(iScreenWidthInPixels);
		dlgProperties->Edit10->Text = strScreenWidth;

		// Screen Height in pixels
		iScreenHeightInPixels = Screen->Height;
		UnicodeString strScreenHeight(iScreenHeightInPixels);
		dlgProperties->Edit11->Text = strScreenHeight;

		// Work area
		iWorkAreaWidthInPixels = Screen->WorkAreaWidth;
		UnicodeString strWorkAreaWidth(iWorkAreaWidthInPixels);
		dlgProperties->Edit12->Text = strWorkAreaWidth;

		iWorkAreaHeightInPixels = Screen->WorkAreaHeight;
		UnicodeString strWorkAreaHeight(iWorkAreaHeightInPixels);
		dlgProperties->Edit13->Text = strWorkAreaHeight;

		// Junior school math: a**2 + b**2 = c**2
		iScreenSizeInPixels = sqrt(iScreenWidthInPixels*iScreenWidthInPixels + iScreenHeightInPixels*iScreenHeightInPixels);
		UnicodeString strpixsize(iScreenSizeInPixels);
		dlgProperties->Edit14->Text = strpixsize;

        // Guessing 27" monitor as a starter
		iScreenPPI = iScreenSizeInPixels / 27;
		dlgProperties->Edit15->Text = iScreenPPI;

		//UnicodeString strii(17);

		dlgProperties->ComboBox1->Items->Add( 15);
		dlgProperties->ComboBox1->Items->Add( 17);
		dlgProperties->ComboBox1->Items->Add( 19);
		dlgProperties->ComboBox1->Items->Add( 20);
		dlgProperties->ComboBox1->Items->Add( 22);
		dlgProperties->ComboBox1->Items->Add( 24);
		dlgProperties->ComboBox1->Items->Add( 27);
		dlgProperties->ComboBox1->Items->Add( 28);
		dlgProperties->ComboBox1->Items->Add( 32);
		dlgProperties->ComboBox1->Items->Add( 34);
		dlgProperties->ComboBox1->Items->Add( 35);
		dlgProperties->ComboBox1->Items->Add( 43);
		dlgProperties->ComboBox1->Items->Add( 49);

		dlgProperties->ComboBox1->ItemIndex = 6;

		dlgProperties->ShowModal();
		if( dlgProperties -> iretState == 1 ) {

			//
		}

		dlgProperties->DisposeOf();
	}
	catch(...)
	{
		ShowMessage("Image properties did not succeed");
	}

}

Det som ligger av kode i selve dialogboksen, er å foreta en beregning hver gang du endrer skjermstørrelse. Da beregnes verdien av pixels/inch.

//---------------------------------------------------------------------------

void __fastcall TForm6::OnComboBoxChange(TObject *Sender)
{

	UnicodeString strSelected = ComboBox1->Selected->Text;
	int isize = strSelected.ToInt();
	UnicodeString scrSize = Edit14->Text;
	int iscrSize = scrSize.ToInt();
	int iPixPerInch = round(iscrSize / isize);

	Edit15->Text = iPixPerInch;
}