Image.PropertyItems Eigenschaft

Definition

Ruft alle in diesem Image gespeicherten Eigenschaftenelemente (Metadaten) ab.Gets all the property items (pieces of metadata) stored in this Image.

public:
 property cli::array <System::Drawing::Imaging::PropertyItem ^> ^ PropertyItems { cli::array <System::Drawing::Imaging::PropertyItem ^> ^ get(); };
[System.ComponentModel.Browsable(false)]
public System.Drawing.Imaging.PropertyItem[] PropertyItems { get; }
[<System.ComponentModel.Browsable(false)>]
member this.PropertyItems : System.Drawing.Imaging.PropertyItem[]
Public ReadOnly Property PropertyItems As PropertyItem()

Eigenschaftswert

PropertyItem[]

Ein Array von PropertyItem-Objekten, eines für jedes im Bild gespeicherte Eigenschaftenelement.An array of PropertyItem objects, one for each property item stored in the image.

Attribute

Beispiele

Im folgenden Codebeispiel wird veranschaulicht, wie die Metadaten in einer Bilddatei mithilfe der System.Drawing.Imaging.PropertyItem -Klasse und der-Eigenschaft gelesen und angezeigt werden PropertyItems .The following code example demonstrates how to read and display the metadata in an image file using the System.Drawing.Imaging.PropertyItem class and the PropertyItems property.

Dieses Beispiel ist so konzipiert, dass ein Windows-Formular verwendet wird, das den- System.Drawing.Imaging Namespace importiert.This example is designed to be used a Windows Form that imports the System.Drawing.Imaging namespace. Fügen Sie den Code in das Formular ein, und ändern Sie den Pfad in, fakePhoto.jpg um auf eine Bilddatei auf Ihrem System zu verweisen.Paste the code into the form and change the path to fakePhoto.jpg to point to an image file on your system. Ruft die ExtractMetaData -Methode auf, wenn das-Ereignis des Formulars behandelt Paint wird, und übergibt e als PaintEventArgs .Call the ExtractMetaData method when handling the form's Paint event, passing e as PaintEventArgs.

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.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 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

Hinweise

Wenn das Bild keine Eigenschaften Elemente aufweist oder wenn das Bildformat keine Eigenschafts Elemente unterstützt, PropertyItems gibt ein leeres Array zurück (d. h. ein Array der Länge 0 (null)).If the image has no property items or if the image format does not support property items, PropertyItems returns an empty array (that is, an array of length zero).

Gilt für: