Image.PropertyItems-Eigenschaft
Ruft alle in diesem Image gespeicherten Eigenschaftenelemente (Metadaten) ab.
Namespace: System.Drawing
Assembly: System.Drawing (in system.drawing.dll)
Syntax
'Declaration
Public ReadOnly Property PropertyItems As PropertyItem()
'Usage
Dim instance As Image
Dim value As PropertyItem()
value = instance.PropertyItems
public PropertyItem[] PropertyItems { get; }
public:
property array<PropertyItem^>^ PropertyItems {
array<PropertyItem^>^ get ();
}
/** @property */
public PropertyItem[] get_PropertyItems ()
public function get PropertyItems () : PropertyItem[]
Eigenschaftenwert
Ein Array von PropertyItem-Objekten, eines für jedes im Bild gespeicherte Eigenschaftenelement.
Hinweise
Wenn keine Eigenschaftenelemente für das Bild vorhanden sind oder das Bildformat keine Eigenschaftenelemente unterstützt, gibt PropertyItems ein leeres Array zurück, d. h. ein Array mit der Länge 0 (null).
Beispiel
Im folgenden Codebeispiel wird veranschaulicht, wie die Metadaten mithilfe der System.Drawing.Imaging.PropertyItem-Klasse und der PropertyItems-Eigenschaft in einer Bilddatei gelesen und angezeigt werden.
Dieses Beispiel ist für die Verwendung in einem Windows Form vorgesehen, das den System.Drawing.Imaging-Namespace importiert. Fügen Sie den Code in das Formular ein, und ändern Sie den Pfad in fakePhoto.jpg, um auf eine Bilddatei im System zu zeigen. Rufen Sie die ExtractMetaData-Methode beim Behandeln des Paint-Ereignisses des Formulars auf, und übergeben Sie dabei e als PaintEventArgs.
Private Sub ExtractMetaData(ByVal e As PaintEventArgs)
Try
'Create an Image object.
Dim theImage As Image = New Bitmap("c:\fakePhoto.jpg")
'Get the PropertyItems property from image.
Dim propItems As PropertyItem() = theImage.PropertyItems
'Set up the display.
Dim font As New font("Arial", 10)
Dim blackBrush As New SolidBrush(Color.Black)
Dim X As Integer = 0
Dim Y As Integer = 0
'For each PropertyItem in the array, display the id, type, and length.
Dim count As Integer = 0
Dim propItem As PropertyItem
For Each propItem In propItems
e.Graphics.DrawString("Property Item " + count.ToString(), _
font, blackBrush, X, Y)
Y += font.Height
e.Graphics.DrawString(" iD: 0x" & propItem.Id.ToString("x"), _
font, blackBrush, X, Y)
Y += font.Height
e.Graphics.DrawString(" type: " & propItem.Type.ToString(), _
font, blackBrush, X, Y)
Y += font.Height
e.Graphics.DrawString(" length: " & propItem.Len.ToString() & _
" bytes", font, blackBrush, X, Y)
Y += font.Height
count += 1
Next propItem
font.Dispose()
Catch ex As ArgumentException
MessageBox.Show("There was an error. Make sure the path to the image file is valid.")
End Try
End Sub
private void ExtractMetaData(PaintEventArgs e)
{
try
{
// Create an Image object.
Image theImage = new Bitmap("c:\\fakePhoto.jpg");
// Get the PropertyItems property from image.
PropertyItem[] propItems = theImage.PropertyItems;
// Set up the display.
Font font1 = new Font("Arial", 10);
SolidBrush blackBrush = new SolidBrush(Color.Black);
int X = 0;
int Y = 0;
// For each PropertyItem in the array, display the id,
// type, and length.
int count = 0;
foreach ( PropertyItem propItem in propItems )
{
e.Graphics.DrawString("Property Item " +
count.ToString(), font1, blackBrush, X, Y);
Y += font1.Height;
e.Graphics.DrawString(" ID: 0x" +
propItem.Id.ToString("x"), font1, blackBrush, X, Y);
Y += font1.Height;
e.Graphics.DrawString(" type: " +
propItem.Type.ToString(), font1, blackBrush, X, Y);
Y += font1.Height;
e.Graphics.DrawString(" length: " +
propItem.Len.ToString() +
" bytes", font1, blackBrush, X, Y);
Y += font1.Height;
count += 1;
}
font1.Dispose();
}
catch(Exception)
{
MessageBox.Show("There was an error." +
"Make sure the path to the image file is valid.");
}
}
private:
void ExtractMetaData( PaintEventArgs^ e )
{
try
{
// Create an Image object.
Image^ theImage = gcnew Bitmap( "c:\\fakePhoto.jpg" );
// Get the PropertyItems property from image.
array<PropertyItem^>^propItems = theImage->PropertyItems;
// Set up the display.
System::Drawing::Font^ font1 = gcnew System::Drawing::Font( "Arial",10 );
SolidBrush^ blackBrush = gcnew SolidBrush( Color::Black );
int X = 0;
int Y = 0;
// For each PropertyItem in the array, display the id,
// type, and length.
int count = 0;
System::Collections::IEnumerator^ myEnum = propItems->GetEnumerator();
while ( myEnum->MoveNext() )
{
PropertyItem^ propItem = safe_cast<PropertyItem^>(myEnum->Current);
e->Graphics->DrawString( String::Format( "Property Item {0}", count ), font1, blackBrush, (float)X, (float)Y );
Y += font1->Height;
e->Graphics->DrawString( String::Format( " ID: 0x{0}", propItem->Id.ToString( "x" ) ), font1, blackBrush, (float)X, (float)Y );
Y += font1->Height;
e->Graphics->DrawString( String::Format( " type: {0}", propItem->Type ), font1, blackBrush, (float)X, (float)Y );
Y += font1->Height;
e->Graphics->DrawString( String::Format( " length: {0} bytes", propItem->Len ), font1, blackBrush, (float)X, (float)Y );
Y += font1->Height;
count += 1;
}
delete font1;
}
catch ( Exception^ )
{
MessageBox::Show( "There was an error."
"Make sure the path to the image file is valid." );
}
}
private void ExtractMetaData(PaintEventArgs e)
{
try {
// Create an Image object.
Image theImage = new Bitmap("c:\\fakePhoto.jpg");
// Get the PropertyItems property from image.
PropertyItem propItems[] = theImage.get_PropertyItems();
// Set up the display.
Font font1 = new Font("Arial", 10);
SolidBrush blackBrush = new SolidBrush(Color.get_Black());
int X = 0;
int Y = 0;
// For each PropertyItem in the array, display the id,
// type, and length.
int count = 0;
//foreach (PropertyItem propItem in propItems)
for (int iCtr = 0; iCtr < propItems.length; iCtr++) {
PropertyItem propItem = propItems[iCtr];
e.get_Graphics().DrawString("Property Item "
+ System.Convert.ToString(count), font1, blackBrush, X, Y);
Y += font1.get_Height();
e.get_Graphics().DrawString(" ID: 0x"
+ ((System.Int32)propItem.get_Id()).ToString("x"), font1,
blackBrush, X, Y);
Y += font1.get_Height();
e.get_Graphics().DrawString(" type: "
+ System.Convert.ToString(propItem.get_Type()), font1,
blackBrush, X, Y);
Y += font1.get_Height();
e.get_Graphics().DrawString(" length: "
+ System.Convert.ToString(propItem.get_Len()) + " bytes",
font1, blackBrush, X, Y);
Y += font1.get_Height();
count += 1;
}
font1.Dispose();
}
catch (System.Exception exp) {
MessageBox.Show(("There was an error."
+ "Make sure the path to the image file is valid."));
}
} //ExtractMetaData
Plattformen
Windows 98, Windows 2000 SP4, Windows CE, Windows Millennium Edition, Windows Mobile für Pocket PC, Windows Mobile für Smartphone, Windows Server 2003, Windows XP Media Center Edition, Windows XP Professional x64 Edition, Windows XP SP2, Windows XP Starter Edition
.NET Framework unterstützt nicht alle Versionen sämtlicher Plattformen. Eine Liste der unterstützten Versionen finden Sie unter Systemanforderungen.
Versionsinformationen
.NET Framework
Unterstützt in: 2.0, 1.1, 1.0
Siehe auch
Referenz
Image-Klasse
Image-Member
System.Drawing-Namespace