我試圖從.aspx頁面返回一個透明的GIF在網頁中顯示。我試圖讓圖像具有透明度,但我只是不斷讓黑色成爲圖像應該透明的地方。如何使用System.Drawing繪製透明圖像?
有誰知道我在做什麼錯?
Protected Sub Page_Load(ByVal sender As Object, ByVal e As System.EventArgs) _
Handles Me.Load
'' Change the response headers to output a GIF image.
Response.Clear()
Response.ContentType = "image/gif"
Dim width = 110
Dim height = width
'' Create a new 32-bit bitmap image
Dim b = New Bitmap(width, height)
'' Create Grahpics object for drawing
Dim g = Graphics.FromImage(b)
Dim rect = New Rectangle(0, 0, width - 1, height - 1)
'' Fill in with Transparent
Dim tbrush = New System.Drawing.SolidBrush(Color.Transparent)
g.FillRectangle(tbrush, rect)
'' Draw Circle Border
Dim bPen = Pens.Red
g.DrawPie(bPen, rect, 0, 365)
'' Fill in Circle
Dim cbrush = New SolidBrush(Color.LightBlue)
g.FillPie(cbrush, rect, 0, 365)
'' Clean up
g.Flush()
g.Dispose()
'' Make Transparent
b.MakeTransparent()
b.Save(Response.OutputStream, Imaging.ImageFormat.Gif)
Response.Flush()
Response.End()
End Sub
我刪除了我的帖子,所以它不會混亂這個了。 – mattlant 2008-10-09 23:34:23