BitmapData::Scan0 Property


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Gets or sets the address of the first pixel data in the bitmap. This can also be thought of as the first scan line in the bitmap.

Namespace:   System.Drawing.Imaging
Assembly:  System.Drawing (in System.Drawing.dll)

property IntPtr Scan0 {
	IntPtr get();
	void set(IntPtr value);

Property Value

Type: System::IntPtr

The address of the first pixel data in the bitmap.

The following code example demonstrates how to use the PixelFormat, Height, Width, and Scan0 properties; the LockBits and UnlockBits methods; and the ImageLockMode enumeration. This example is designed to be used with Windows Forms. To run this example, paste it into a form and handle the form's Paint event by calling the LockUnlockBitsExample method, passing e as PaintEventArgs.


The following example code was created for use with an image with the Format24bppRgb format.

void LockUnlockBitsExample( PaintEventArgs^ e )
   // Create a new bitmap.
   Bitmap^ bmp = gcnew Bitmap( "c:\\fakePhoto.jpg" );

   // Lock the bitmap's bits.  
   Rectangle rect = Rectangle(0,0,bmp->Width,bmp->Height);
   System::Drawing::Imaging::BitmapData^ bmpData = bmp->LockBits( rect, System::Drawing::Imaging::ImageLockMode::ReadWrite, bmp->PixelFormat );

   // Get the address of the first line.
   IntPtr ptr = bmpData->Scan0;

   // Declare an array to hold the bytes of the bitmap.
   // This code is specific to a bitmap with 24 bits per pixels.
   int bytes = Math::Abs(bmpData->Stride) * bmp->Height;
   array<Byte>^rgbValues = gcnew array<Byte>(bytes);

   // Copy the RGB values into the array.
   System::Runtime::InteropServices::Marshal::Copy( ptr, rgbValues, 0, bytes );

   // Set every third value to 255.  
   for ( int counter = 2; counter < rgbValues->Length; counter += 3 )
      rgbValues[ counter ] = 255;

   // Copy the RGB values back to the bitmap
   System::Runtime::InteropServices::Marshal::Copy( rgbValues, 0, ptr, bytes );

   // Unlock the bits.
   bmp->UnlockBits( bmpData );

   // Draw the modified image.
   e->Graphics->DrawImage( bmp, 0, 150 );

.NET Framework
Available since 1.1
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