BitmapData Class

Definition

Namespace:

System.Drawing.Imaging

Assembly:

System.Drawing.Common.dll

Source:

BitmapData.cs

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

C#

public sealed class BitmapData

Inheritance

Object

BitmapData

Examples

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.

C#

private void LockUnlockBitsExample(PaintEventArgs e)
    {

        // Create a new bitmap.
        Bitmap bmp = new Bitmap("c:\\fakePhoto.jpg");

        // Lock the bitmap's bits.  
        Rectangle rect = new 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.
        int bytes  = Math.Abs(bmpData.Stride) * bmp.Height;
        byte[] rgbValues = new byte[bytes];

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

        // Set every third value to 255. A 24bpp bitmap will look red.  
        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);
    }

Constructors

BitmapData()

Initializes a new instance of the BitmapData class.

Properties

Height	Gets or sets the pixel height of the Bitmap object. Also sometimes referred to as the number of scan lines.
PixelFormat	Gets or sets the format of the pixel information in the Bitmap object that returned this BitmapData object.
Reserved	Reserved. Do not use.
Scan0	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.
Stride	Gets or sets the stride width (also called scan width) of the Bitmap object.
Width	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.

Applies to