Image.Save Metodo

Origine:

Image.cs

Origine:

Image.cs

Origine:

Image.cs

public:
 void Save(System::String ^ filename, System::Drawing::Imaging::ImageCodecInfo ^ encoder, System::Drawing::Imaging::EncoderParameters ^ encoderParams);

public void Save (string filename, System.Drawing.Imaging.ImageCodecInfo encoder, System.Drawing.Imaging.EncoderParameters encoderParams);

public void Save (string filename, System.Drawing.Imaging.ImageCodecInfo encoder, System.Drawing.Imaging.EncoderParameters? encoderParams);

member this.Save : string * System.Drawing.Imaging.ImageCodecInfo * System.Drawing.Imaging.EncoderParameters -> unit

Public Sub Save (filename As String, encoder As ImageCodecInfo, encoderParams As EncoderParameters)

Parametri

Eccezioni

Esempio

Nell'esempio seguente viene creato un Bitmap oggetto da un file BMP. Il codice salva la bitmap in tre file JPEG, ognuno con un livello di qualità diverso.

#using <System.Drawing.dll>

using namespace System;
using namespace System::Drawing;
using namespace System::Drawing::Imaging;
static ImageCodecInfo^ GetEncoderInfo( ImageFormat^ format );
int main()
{
   Bitmap^ myBitmap;
   ImageCodecInfo^ myImageCodecInfo;
   Encoder^ myEncoder;
   EncoderParameter^ myEncoderParameter;
   EncoderParameters^ myEncoderParameters;
   
   // Create a Bitmap object based on a BMP file.
   myBitmap = gcnew Bitmap( "Shapes.bmp" );
   
   // Get an ImageCodecInfo object that represents the JPEG codec.
   myImageCodecInfo = GetEncoderInfo( ImageFormat->Jpeg );
   
   // Create an Encoder object based on the GUID
   // for the Quality parameter category.
   myEncoder = Encoder::Quality;
   
   // Create an EncoderParameters object.
   // An EncoderParameters object has an array of EncoderParameter
   // objects. In this case, there is only one
   // EncoderParameter object in the array.
   myEncoderParameters = gcnew EncoderParameters( 1 );
   
   // Save the bitmap as a JPEG file with quality level 25.
   myEncoderParameter = gcnew EncoderParameter( myEncoder,__int64(25) );
   myEncoderParameters->Param[ 0 ] = myEncoderParameter;
   myBitmap->Save( "Shapes025.jpg", myImageCodecInfo, myEncoderParameters );
   
   // Save the bitmap as a JPEG file with quality level 50.
   myEncoderParameter = gcnew EncoderParameter( myEncoder,__int64(50) );
   myEncoderParameters->Param[ 0 ] = myEncoderParameter;
   myBitmap->Save( "Shapes050.jpg", myImageCodecInfo, myEncoderParameters );
   
   // Save the bitmap as a JPEG file with quality level 75.
   myEncoderParameter = gcnew EncoderParameter( myEncoder,__int64(75) );
   myEncoderParameters->Param[ 0 ] = myEncoderParameter;
   myBitmap->Save( "Shapes075.jpg", myImageCodecInfo, myEncoderParameters );
}

static ImageCodecInfo^ GetEncoderInfo( ImageFormat^ format )
{
   int j;
   array<ImageCodecInfo^>^encoders;
   encoders = ImageCodecInfo::GetImageEncoders();
   for ( j = 0; j < encoders->Length; ++j )
   {
      if ( encoders[ j ]->FormatID == format->Guid)
            return encoders[ j ];

   }
   return nullptr;
}

using System;
using System.Drawing;
using System.Drawing.Imaging;
class Example_SetJPEGQuality
{
    public static void Main()
    {
        Bitmap myBitmap;
        ImageCodecInfo myImageCodecInfo;
        Encoder myEncoder;
        EncoderParameter myEncoderParameter;
        EncoderParameters myEncoderParameters;
                     
        // Create a Bitmap object based on a BMP file.
        myBitmap = new Bitmap("Shapes.bmp");
                     
        // Get an ImageCodecInfo object that represents the JPEG codec.
        myImageCodecInfo = GetEncoderInfo("image/jpeg");
                     
        // Create an Encoder object based on the GUID
                     
        // for the Quality parameter category.
        myEncoder = Encoder.Quality;
                     
        // Create an EncoderParameters object.
                     
        // An EncoderParameters object has an array of EncoderParameter
                     
        // objects. In this case, there is only one
                     
        // EncoderParameter object in the array.
        myEncoderParameters = new EncoderParameters(1);
                     
        // Save the bitmap as a JPEG file with quality level 25.
        myEncoderParameter = new EncoderParameter(myEncoder, 25L);
        myEncoderParameters.Param[0] = myEncoderParameter;
        myBitmap.Save("Shapes025.jpg", myImageCodecInfo, myEncoderParameters);
                     
        // Save the bitmap as a JPEG file with quality level 50.
        myEncoderParameter = new EncoderParameter(myEncoder, 50L);
        myEncoderParameters.Param[0] = myEncoderParameter;
        myBitmap.Save("Shapes050.jpg", myImageCodecInfo, myEncoderParameters);
                     
        // Save the bitmap as a JPEG file with quality level 75.
        myEncoderParameter = new EncoderParameter(myEncoder, 75L);
        myEncoderParameters.Param[0] = myEncoderParameter;
        myBitmap.Save("Shapes075.jpg", myImageCodecInfo, myEncoderParameters);
    }
    private static ImageCodecInfo GetEncoderInfo(String mimeType)
    {
        int j;
        ImageCodecInfo[] encoders;
        encoders = ImageCodecInfo.GetImageEncoders();
        for(j = 0; j < encoders.Length; ++j)
        {
            if(encoders[j].MimeType == mimeType)
                return encoders[j];
        }
        return null;
    }
}

Imports System.Drawing
Imports System.Drawing.Imaging


Class Example_SetJPEGQuality

    Public Shared Sub Main()
        Dim myBitmap As Bitmap
        Dim myImageCodecInfo As ImageCodecInfo
        Dim myEncoder As Encoder
        Dim myEncoderParameter As EncoderParameter
        Dim myEncoderParameters As EncoderParameters

        ' Create a Bitmap object based on a BMP file.
        myBitmap = New Bitmap("Shapes.bmp")

        ' Get an ImageCodecInfo object that represents the JPEG codec.
        myImageCodecInfo = GetEncoderInfo(ImageFormat.Jpeg)

        ' Create an Encoder object based on the GUID
        ' for the Quality parameter category.
        myEncoder = Encoder.Quality

        ' Create an EncoderParameters object.
        ' An EncoderParameters object has an array of EncoderParameter
        ' objects. In this case, there is only one
        ' EncoderParameter object in the array.
        myEncoderParameters = New EncoderParameters(1)

        ' Save the bitmap as a JPEG file with quality level 25.
        myEncoderParameter = New EncoderParameter(myEncoder, CType(25L, Int32))
        myEncoderParameters.Param(0) = myEncoderParameter
        myBitmap.Save("Shapes025.jpg", myImageCodecInfo, myEncoderParameters)

        ' Save the bitmap as a JPEG file with quality level 50.
        myEncoderParameter = New EncoderParameter(myEncoder, CType(50L, Int32))
        myEncoderParameters.Param(0) = myEncoderParameter
        myBitmap.Save("Shapes050.jpg", myImageCodecInfo, myEncoderParameters)

        ' Save the bitmap as a JPEG file with quality level 75.
        myEncoderParameter = New EncoderParameter(myEncoder, CType(75L, Int32))
        myEncoderParameters.Param(0) = myEncoderParameter
        myBitmap.Save("Shapes075.jpg", myImageCodecInfo, myEncoderParameters)

    End Sub

    Private Shared Function GetEncoderInfo(ByVal format As ImageFormat) As ImageCodecInfo
        Dim j As Integer
        Dim encoders() As ImageCodecInfo
        encoders = ImageCodecInfo.GetImageEncoders()

        j = 0
        While j < encoders.Length
            If encoders(j).FormatID = format.Guid Then
                Return encoders(j)
            End If
            j += 1
        End While
        Return Nothing

    End Function 'GetEncoderInfo
End Class

Commenti

Il salvataggio dell'immagine nello stesso file creato da non è consentito e genera un'eccezione.

Vedi anche

• Procedura: Impostare il livello di compressione JPEG

Origine:

Image.cs

Origine:

Image.cs

Origine:

Image.cs

public:
 void Save(System::IO::Stream ^ stream, System::Drawing::Imaging::ImageCodecInfo ^ encoder, System::Drawing::Imaging::EncoderParameters ^ encoderParams);

public void Save (System.IO.Stream stream, System.Drawing.Imaging.ImageCodecInfo encoder, System.Drawing.Imaging.EncoderParameters encoderParams);

public void Save (System.IO.Stream stream, System.Drawing.Imaging.ImageCodecInfo encoder, System.Drawing.Imaging.EncoderParameters? encoderParams);

member this.Save : System.IO.Stream * System.Drawing.Imaging.ImageCodecInfo * System.Drawing.Imaging.EncoderParameters -> unit

Public Sub Save (stream As Stream, encoder As ImageCodecInfo, encoderParams As EncoderParameters)

Parametri

Eccezioni

Commenti

Non salvare un'immagine nello stesso flusso usato per costruire l'immagine. In questo modo potrebbe danneggiare il flusso.

L'immagine deve essere salvata nel flusso in corrispondenza di un offset pari a zero. Se tutti i dati aggiuntivi sono stati scritti nel flusso prima di salvare l'immagine, i dati dell'immagine nel flusso verranno danneggiati.

Origine:

Image.cs

Origine:

Image.cs

Origine:

Image.cs

public:
 void Save(System::String ^ filename, System::Drawing::Imaging::ImageFormat ^ format);

public void Save (string filename, System.Drawing.Imaging.ImageFormat format);

member this.Save : string * System.Drawing.Imaging.ImageFormat -> unit

Public Sub Save (filename As String, format As ImageFormat)

Parametri

Eccezioni

Esempio

Nell'esempio di codice seguente viene illustrato come costruire una bitmap da un tipo e come usare il Save metodo . Per eseguire questo esempio, incollare il codice in un Windows Form. Gestire l'evento del Paint modulo e chiamare il ConstructFromResourceSaveAsGif metodo, passando e come PaintEventArgs

private:
    void ConstructFromResourceSaveAsGif(PaintEventArgs^ e)
    {
        // Construct a bitmap from the button image resource.
        Bitmap^ bmp1 = gcnew Bitmap(Button::typeid, "Button.bmp");
        String^ savePath =  
            Environment::GetEnvironmentVariable("TEMP") + "\\Button.bmp";

        try
        {
            // Save the image as a GIF.
            bmp1->Save(savePath, System::Drawing::Imaging::ImageFormat::Gif);
        }
        catch (IOException^)
        {
            // Carry on regardless
        }

        // Construct a new image from the GIF file.
        Bitmap^ bmp2 = nullptr;
        if (File::Exists(savePath))
        {
            bmp2 = gcnew Bitmap(savePath);
        }

        // Draw the two images.
        e->Graphics->DrawImage(bmp1, Point(10, 10));

        // If bmp1 did not save to disk, bmp2 may be null
        if (bmp2 != nullptr)
        {
            e->Graphics->DrawImage(bmp2, Point(10, 40));
        }

        // Dispose of the image files.
        delete bmp1;
        if (bmp2 != nullptr)
        {
            delete bmp2;
        }
    }

private void ConstructFromResourceSaveAsGif(PaintEventArgs e)
{

    // Construct a bitmap from the button image resource.
    Bitmap bmp1 = new Bitmap(typeof(Button), "Button.bmp");

    // Save the image as a GIF.
    bmp1.Save("c:\\button.gif", System.Drawing.Imaging.ImageFormat.Gif);

    // Construct a new image from the GIF file.
    Bitmap bmp2 = new Bitmap("c:\\button.gif");

    // Draw the two images.
    e.Graphics.DrawImage(bmp1, new Point(10, 10));
    e.Graphics.DrawImage(bmp2, new Point(10, 40));

    // Dispose of the image files.
    bmp1.Dispose();
    bmp2.Dispose();
}

Private Sub ConstructFromResourceSaveAsGif(ByVal e As PaintEventArgs)

    ' Construct a bitmap from the button image resource.
    Dim bmp1 As New Bitmap(GetType(Button), "Button.bmp")

    ' Save the image as a GIF.
    bmp1.Save("c:\button.gif", System.Drawing.Imaging.ImageFormat.Gif)

    ' Construct a new image from the GIF file.
    Dim bmp2 As New Bitmap("c:\button.gif")

    ' Draw the two images.
    e.Graphics.DrawImage(bmp1, New Point(10, 10))
    e.Graphics.DrawImage(bmp2, New Point(10, 40))

    ' Dispose of the image files.
    bmp1.Dispose()
    bmp2.Dispose()
End Sub

Origine:

Image.cs

Origine:

Image.cs

Origine:

Image.cs

public:
 void Save(System::IO::Stream ^ stream, System::Drawing::Imaging::ImageFormat ^ format);

public void Save (System.IO.Stream stream, System.Drawing.Imaging.ImageFormat format);

member this.Save : System.IO.Stream * System.Drawing.Imaging.ImageFormat -> unit

Public Sub Save (stream As Stream, format As ImageFormat)

Parametri

Eccezioni

Commenti

È consigliabile evitare di salvare un'immagine nello stesso flusso usato per crearlo. In questo modo potrebbe danneggiare il flusso.

L'immagine deve essere salvata nel flusso in corrispondenza di un offset pari a zero. Se tutti i dati aggiuntivi sono stati scritti nel flusso prima di salvare l'immagine, i dati dell'immagine nel flusso verranno danneggiati.

Origine:

Image.cs

Origine:

Image.cs

Origine:

Image.cs

public:
 void Save(System::String ^ filename);

public void Save (string filename);

member this.Save : string -> unit

Public Sub Save (filename As String)

Parametri

Eccezioni

Esempio

Nell'esempio di codice seguente viene illustrato come chiamare il Save metodo . Questo esempio è progettato per essere usato con Windows Forms. Create un modulo contenente un pulsante denominato Button5. Incollare il codice nel modulo e associare il metodo all'evento del Click pulsante.

private:
   void Button5_Click( System::Object^ /*sender*/, System::EventArgs^ /*e*/ )
   {
      try
      {
         if ( image1 != nullptr )
         {
            image1->Save( "c:\\myBitmap.bmp" );
            Button5->Text = "Saved file.";
         }
      }
      catch ( Exception^ ) 
      {
         MessageBox::Show( "There was a problem saving the file."
         "Check the file permissions." );
      }
   }

private void Button5_Click(System.Object sender, System.EventArgs e)
{
    try
    {
        if (image1 != null)
        {
            image1.Save("c:\\myBitmap.bmp");
            Button5.Text = "Saved file.";
        }
    }
    catch(Exception)
    {
        MessageBox.Show("There was a problem saving the file." +
            "Check the file permissions.");
    }
}

Private Sub Button5_Click(ByVal sender As System.Object, _
    ByVal e As System.EventArgs) Handles Button5.Click
    Try
        If (image1 IsNot Nothing) Then
            image1.Save("c:\myBitmap.bmp")
            Button5.Text = "Saved file."
        End If
    Catch ex As Exception
        MessageBox.Show("There was a problem saving the file." _
        & "Check the file permissions.")
    End Try

End Sub

Commenti

Se non esiste alcun codificatore per il formato di file dell'immagine, viene usato il codificatore PNG (Portable Network Graphics). Quando si usa il Save metodo per salvare un'immagine grafica come file WMF (Windows Metafile Format) o Enhanced Metafile Format (EMF), il file risultante viene salvato come file PNG (Portable Network Graphics). Questo comportamento si verifica perché il componente GDI+ di .NET Framework non dispone di un codificatore che è possibile usare per salvare i file come file wmf o .emf.

Il salvataggio dell'immagine nello stesso file creato da non è consentito e genera un'eccezione.