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Image.PropertyItems Propiedad

Definición

Obtiene todos los elementos de propiedad (fragmentos de metadatos) almacenados en 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()

Valor de propiedad

Matriz de objetos PropertyItem, uno para cada elemento de propiedad almacenado en la imagen.

Atributos

Ejemplos

En el ejemplo de código siguiente se muestra cómo leer y mostrar los metadatos en un archivo de imagen mediante la System.Drawing.Imaging.PropertyItem clase y la PropertyItems propiedad .

Este ejemplo está diseñado para usar un formulario Windows Forms que importa el System.Drawing.Imaging espacio de nombres. Pegue el código en el formulario y cambie la ruta de acceso para fakePhoto.jpg que apunte a un archivo de imagen en el sistema. Llame al ExtractMetaData método al controlar el evento del Paint formulario, pasando e como 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

Comentarios

Si la imagen no tiene elementos de propiedad o si el formato de imagen no admite elementos de propiedad, PropertyItems devuelve una matriz vacía (es decir, una matriz de longitud cero).

Se aplica a

Consulte también