ערוך

שתף באמצעות

Graphics.FromImage(Image) Method

  • Reference

Definition

Namespace:
System.Drawing
Assembly:
System.Drawing.Common.dll
Assembly:
System.Drawing.dll
Package:
System.Drawing.Common v8.0.10
Package:
System.Drawing.Common v9.0.0-rc.2.24474.1
Source:
Graphics.cs
Source:
Graphics.cs
Source:
Graphics.cs
Source:
Graphics.cs
Source:
Graphics.cs

Creates a new Graphics from the specified Image.

public:
 static System::Drawing::Graphics ^ FromImage(System::Drawing::Image ^ image);
public static System.Drawing.Graphics FromImage (System.Drawing.Image image);
static member FromImage : System.Drawing.Image -> System.Drawing.Graphics
Public Shared Function FromImage (image As Image) As Graphics

Parameters

image
Image

Image from which to create the new Graphics.

Returns

Graphics

This method returns a new Graphics for the specified Image.

Exceptions

ArgumentNullException

image is null.

Exception

image has an indexed pixel format or its format is undefined.

Examples

The following code example is designed for use with Windows Forms, and it requires PaintEventArgs e, which is a parameter of the Paint event handler. The code performs the following action:

  • Creates an Image from a graphics file SampImag.jpg in the example folder.

  • Creates a Graphics from the Image.

  • Alters the image by filling a rectangle within it.

  • Draws the Image to the screen.

  • Releases the created Graphics.

public:
   void FromImageImage( PaintEventArgs^ e )
   {
      // Create image.
      Image^ imageFile = Image::FromFile( "SampImag.jpg" );

      // Create graphics object for alteration.
      Graphics^ newGraphics = Graphics::FromImage( imageFile );

      // Alter image.
      newGraphics->FillRectangle( gcnew SolidBrush( Color::Black ), 100, 50, 100, 100 );

      // Draw image to screen.
      e->Graphics->DrawImage( imageFile, PointF(0.0F,0.0F) );

      // Dispose of graphics object.
      delete newGraphics;
   }

private void FromImageImage(PaintEventArgs e)
{

    // Create image.
    Image imageFile = Image.FromFile("SampImag.jpg");

    // Create graphics object for alteration.
    Graphics newGraphics = Graphics.FromImage(imageFile);

    // Alter image.
    newGraphics.FillRectangle(new SolidBrush(Color.Black), 100, 50, 100, 100);

    // Draw image to screen.
    e.Graphics.DrawImage(imageFile, new PointF(0.0F, 0.0F));

    // Dispose of graphics object.
    newGraphics.Dispose();
}

Private Sub FromImageImage2(ByVal e As PaintEventArgs)

    ' Create image.
    Dim imageFile As Image = Image.FromFile("SampImag.jpg")

    ' Create graphics object for alteration.
    Dim newGraphics As Graphics = Graphics.FromImage(imageFile)

    ' Alter image.
    newGraphics.FillRectangle(New SolidBrush(Color.Black), _
    100, 50, 100, 100)

    ' Draw image to screen.
    e.Graphics.DrawImage(imageFile, New PointF(0.0F, 0.0F))

    ' Dispose of graphics object.
    newGraphics.Dispose()
End Sub

Remarks

If the image has an indexed pixel format, this method throws an exception with the message, "A Graphics object cannot be created from an image that has an indexed pixel format." The indexed pixel formats are shown in the following list.

You can save the indexed image as another format by using the Save(String, ImageFormat) method and then retrieve a Graphics object for the new image.

This method also throws an exception if the image has any of the following pixel formats.

You should always call the Dispose method to release the Graphics and related resources created by the FromImage method.

Applies to

See also