本文整理汇总了VB.NET中System.Drawing.Bitmap.UnlockBits方法的典型用法代码示例。如果您正苦于以下问题:VB.NET Bitmap.UnlockBits方法的具体用法?VB.NET Bitmap.UnlockBits怎么用?VB.NET Bitmap.UnlockBits使用的例子?那么恭喜您, 这里精选的方法代码示例或许可以为您提供帮助。您也可以进一步了解该方法所在类System.Drawing.Bitmap
的用法示例。
在下文中一共展示了Bitmap.UnlockBits方法的1个代码示例,这些例子默认根据受欢迎程度排序。您可以为喜欢或者感觉有用的代码点赞,您的评价将有助于系统推荐出更棒的VB.NET代码示例。
示例1: LockUnlockBitsExample
Private Sub LockUnlockBitsExample(ByVal e As PaintEventArgs)
' Create a new bitmap.
Dim bmp As New Bitmap("c:\fakePhoto.jpg")
' Lock the bitmap's bits.
Dim rect As New Rectangle(0, 0, bmp.Width, bmp.Height)
Dim bmpData As System.Drawing.Imaging.BitmapData = bmp.LockBits(rect, _
Drawing.Imaging.ImageLockMode.ReadWrite, bmp.PixelFormat)
' Get the address of the first line.
Dim ptr As IntPtr = bmpData.Scan0
' Declare an array to hold the bytes of the bitmap.
' This code is specific to a bitmap with 24 bits per pixels.
Dim bytes As Integer = Math.Abs(bmpData.Stride) * bmp.Height
Dim rgbValues(bytes - 1) As Byte
' Copy the RGB values into the array.
System.Runtime.InteropServices.Marshal.Copy(ptr, rgbValues, 0, bytes)
' Set every third value to 255. A 24bpp image will look red.
For counter As Integer = 2 To rgbValues.Length - 1 Step 3
rgbValues(counter) = 255
Next
' 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)
End Sub