一个VB.NET写的简单图片缩放处理组件源代码,支持添加半透明效果小图标

  1<comclass(dimage.classid, dimage.eventsid)="" dimage.interfaceid,=""> _   
  2Public Class dImage 
  3
  4#Region "COM GUIDs"   
  5' 这些 GUID 提供该类的 COM 标识及其 COM 接口。   
  6' 如果您更改它们，现有的客户端将再也无法   
  7' 访问该类。   
  8Public Const ClassId As String = "29641F37-8FA4-4ED9-9118-9DA8EFA306B9"   
  9Public Const InterfaceId As String = "06E4B037-2461-4F83-96BE-2A5D1CAAB0CE"   
 10Public Const EventsId As String = "802EBB14-2D4D-416E-BA26-E8ADCD480E26"   
 11#End Region 
 12
 13' 可创建的 COM 类必须具有不带参数的   
 14' Public Sub New()，否则，该类将不会注册到 COM 注册表中，   
 15' 而且不能通过 CreateObject   
 16' 来创建。   
 17Private myImage As Drawing.Bitmap   
 18Private syimg As Drawing.Bitmap   
 19Private syok As Boolean = False   
 20Private myok As Boolean = False   
 21Public Sub New()   
 22MyBase.New()   
 23End Sub   
 24Public WriteOnly Property bigImage() As String   
 25Set(ByVal Value As String)   
 26Try   
 27myImage = New Bitmap(Value)   
 28myok = True   
 29Catch e As IO.IOException   
 30myok = False   
 31End Try   
 32End Set   
 33End Property   
 34Public WriteOnly Property LogoImage() As String   
 35Set(ByVal Value As String)   
 36Try   
 37syimg = New Bitmap(Value)   
 38syok = True   
 39Catch ex As Exception   
 40syok = False   
 41End Try   
 42End Set   
 43End Property   
 44Public Function SaveAs(ByVal ToFile As String, ByVal nWidth As Integer, ByVal nHeight As Integer, ByVal nLogo As Boolean) As String   
 45Try   
 46If myok = False Then   
 47Return "err0"   
 48Exit Function   
 49End If   
 50Dim newbmp As Bitmap = New Bitmap(nWidth, nHeight, Imaging.PixelFormat.Format16bppArgb1555)   
 51Dim iX As Integer   
 52Dim iY As Integer   
 53Dim xMax As Integer   
 54Dim yMax As Integer   
 55For iX = 0 To nWidth - 1   
 56For iY = 0 To nHeight - 1   
 57newbmp.SetPixel(iX, iY, Color.White)   
 58Next   
 59Next   
 60If nWidth &lt; myImage.Width Or nHeight &lt; myImage.Height Then   
 61If myImage.Width / myImage.Height &gt; nWidth / nHeight Then   
 62xMax = nWidth   
 63yMax = myImage.Height * nWidth \ myImage.Width   
 64Else   
 65yMax = nHeight   
 66xMax = myImage.Width * nHeight \ myImage.Height   
 67End If   
 68Else   
 69xMax = myImage.Width   
 70yMax = myImage.Height   
 71End If   
 72Dim tembmp As Bitmap = New Bitmap(myImage, xMax, yMax)   
 73xMax = (newbmp.Width - tembmp.Width) \ 2   
 74yMax = (newbmp.Height - tembmp.Height) \ 2   
 75For iX = 0 To tembmp.Width - 1   
 76For iY = 0 To tembmp.Height - 1   
 77newbmp.SetPixel(iX + xMax, iY + yMax, tembmp.GetPixel(iX, iY))   
 78Next   
 79Next   
 80If syok And nLogo Then   
 81Dim cob As Color   
 82Dim coc As Color   
 83xMax = newbmp.Width - syimg.Width - 4   
 84yMax = newbmp.Height - syimg.Height - 3   
 85For iX = 0 To syimg.Width - 1   
 86For iY = 0 To syimg.Height - 1   
 87cob = syimg.GetPixel(iX, iY)   
 88coc = newbmp.GetPixel(iX + xMax, iY + yMax)   
 89newbmp.SetPixel(iX + xMax, iY + yMax, getnewco(cob, coc))   
 90Next   
 91Next   
 92End If   
 93newbmp.Save(ToFile, Imaging.ImageFormat.Jpeg)   
 94newbmp.Dispose()   
 95tembmp.Dispose()   
 96newbmp = Nothing   
 97tembmp = Nothing   
 98Return "OK"   
 99Catch ex As Exception   
100Return ex.ToString   
101End Try   
102End Function 
103
104Public ReadOnly Property Width() As Integer   
105Get   
106Return myImage.Width   
107End Get   
108End Property   
109Public ReadOnly Property Height() As Integer   
110Get   
111Return myImage.Height   
112End Get   
113End Property   
114Public Sub Close()   
115myImage.Dispose()   
116syimg.Dispose()   
117myImage = Nothing   
118syimg = Nothing   
119End Sub   
120Private Function getnewco(ByVal c1 As Color, ByVal c2 As Color) As Color   
121Dim a1 As Integer = c1.A   
122Dim r1 As Integer = c1.R   
123Dim g1 As Integer = c1.G   
124Dim b1 As Integer = c1.B   
125Dim a2 As Integer = c2.A   
126Dim r2 As Integer = c2.R   
127Dim g2 As Integer = c2.G   
128Dim b2 As Integer = c2.B   
129a2 = 255 - a1   
130r1 = CInt((r1 * a1 / 255) + (r2 * a2 / 255))   
131g1 = CInt((g1 * a1 / 255) + (g2 * a2 / 255))   
132b1 = CInt((b1 * a1 / 255) + (b2 * a2 / 255))   
133Return Color.FromArgb(a1, r1, g1, b1)   
134End Function 
135
136End Class</comclass(dimage.classid,>