BitmapData Class

 
System_CAPS_noteNote

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Specifies the attributes of a bitmap image. The BitmapData class is used by the LockBits and UnlockBits methods of the Bitmap class. Not inheritable.

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

System::Object
  System.Drawing.Imaging::BitmapData

public ref class BitmapData sealed 

NameDescription
System_CAPS_pubmethodBitmapData()

Initializes a new instance of the BitmapData class.

NameDescription
System_CAPS_pubpropertyHeight

Gets or sets the pixel height of the Bitmap object. Also sometimes referred to as the number of scan lines.

System_CAPS_pubpropertyPixelFormat

Gets or sets the format of the pixel information in the Bitmap object that returned this BitmapData object.

System_CAPS_pubpropertyReserved

Reserved. Do not use.

System_CAPS_pubpropertyScan0

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.

System_CAPS_pubpropertyStride

Gets or sets the stride width (also called scan width) of the Bitmap object.

System_CAPS_pubpropertyWidth

Gets or sets the pixel width of the Bitmap object. This can also be thought of as the number of pixels in one scan line.

NameDescription
System_CAPS_pubmethodEquals(Object^)

Determines whether the specified object is equal to the current object.(Inherited from Object.)

System_CAPS_pubmethodGetHashCode()

Serves as the default hash function. (Inherited from Object.)

System_CAPS_pubmethodGetType()

Gets the Type of the current instance.(Inherited from Object.)

System_CAPS_pubmethodToString()

Returns a string that represents the current object.(Inherited from Object.)

The following code example demonstrates how to use the BitmapData class with the LockBits and UnlockBits methods. 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.

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

Any public static ( Shared in Visual Basic) members of this type are thread safe. Any instance members are not guaranteed to be thread safe.

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