发个封装好的类,提高bitmap.GetPixel和bitmap.SetPixel速度

[zj_zwl]

我写的这个类很简单,只封装了两个常用方法,根据实际需求,可自行改造它!

Imports System.Drawing.Imaging

Public Class FastBitmap

    Private bmpData As BitmapData
    Private ptr As IntPtr = IntPtr.Zero
    Private rgbValues() As Byte = Nothing
    Private bytes As Integer
    Private mWidth As Integer
    Private id As Integer

    ''' <summary>
    ''' 
    ''' </summary>
    ''' <param name="image">设置读写的图片对象</param>
    ''' <remarks></remarks>
    Public Sub New(ByVal image As Bitmap)
        MyClass.Image = image
    End Sub

    Public Sub New()
        '
    End Sub

    ''' <summary>
    ''' 开始读写操作
    ''' </summary>
    ''' <remarks></remarks>
    Public Sub BeginReadWrite()
        If Image Is Nothing Then Throw New Exception("调用BeginReadWrite方法,前必须先设置Image属性!")
        Dim rect As New Rectangle(0, 0, Image.Width, Image.Height)
        bmpData = Image.LockBits(rect, ImageLockMode.ReadWrite, Image.PixelFormat)
        ptr = bmpData.Scan0
        bytes = Math.Abs(bmpData.Stride) * Image.Height
        ReDim rgbValues(bytes - 1)
        System.Runtime.InteropServices.Marshal.Copy(ptr, rgbValues, 0, bytes)
        mWidth = Image.Width
    End Sub

    ''' <summary>
    ''' 获取指定位置的点颜色
    ''' </summary>
    ''' <param name="x"></param>
    ''' <param name="y"></param>
    ''' <returns></returns>
    ''' <remarks></remarks>
    Public Function GetPixel(ByVal x As Integer, ByVal y As Integer) As Color
        If ptr = IntPtr.Zero Then Throw New Exception("读写操作前必须先调用BeginReadWrite方法!")
        id = mWidth * 4 * y + x * 4 '每个点在这变成4个字节(按顺序代表b\g\r\a)
        Return Color.FromArgb(rgbValues(id + 3), _
                              rgbValues(id + 2), _
                              rgbValues(id + 1), _
                              rgbValues(id))
    End Function

    ''' <summary>
    ''' 设置指定位置的点颜色
    ''' </summary>
    ''' <param name="x"></param>
    ''' <param name="y"></param>
    ''' <param name="color"></param>
    ''' <remarks></remarks>
    Public Sub SetPixel(ByVal x As Integer, ByVal y As Integer, ByVal color As Color)
        If ptr = IntPtr.Zero Then Throw New Exception("读写操作前必须先调用BeginReadWrite方法!")
        id = mWidth * 4 * y + x * 4
        rgbValues(id) = color.B
        rgbValues(id + 1) = color.G
        rgbValues(id + 2) = color.R
        rgbValues(id + 3) = color.A
    End Sub

    ''' <summary>
    ''' 结束读取操作
    ''' </summary>
    ''' <remarks></remarks>
    Public Sub EndReadWrite()
        If ptr = IntPtr.Zero Then Return
        System.Runtime.InteropServices.Marshal.Copy(rgbValues, 0, ptr, bytes)
        Image.UnlockBits(bmpData)
        ptr = IntPtr.Zero
        rgbValues = Nothing
    End Sub

    ''' <summary>
    ''' 获取或设置读写的图片对象
    ''' </summary>
    ''' <value></value>
    ''' <returns></returns>
    ''' <remarks></remarks>
    Public Property Image As Bitmap = Nothing

End Class

调用方法很简单,不多啰嗦了

[天下如山]

谢谢分享。

[zj_zwl]

欢迎大家来完善补漏

[fengye89]

多谢分享....