Sub validatecode(ByVal vnum)
Dim img As System.drawing.Bitmap
Dim g As Graphics
Dim r As Random = New Random
Dim gheight As Integer = Int(Len(vnum) * 13)
'gheight为图片宽度, 根据字符长度自动更改图片宽度
img = New Bitmap(gheight, 20)
g = Graphics.FromImage(img)
g.DrawString(vnum, New System.Drawing.Font("Arial", 10), New System.Drawing.SolidBrush(Color.Blue), 3, 3)
'新增，修改、画图片的背景噪音线
For i As Integer = 0 To 10
Dim x1 As Integer
x1 = r.Next(img.Width)
Dim x2 As Integer =r.Next(img.Width)
Dim y1 As Integer =r.Next(img.Height)
Dim y2 As Integer =r.Next(img.Height)
g.DrawLine(New Pen(Color.Silver),x1, y1, x2, y2)
Next i
Dim font As Font
font = New System.Drawing.Font("Arial", 12)
Dim brush As System.Drawing.
Drawing2D.LinearGradientBrush
brush = New System.Drawing.Drawing2D.LinearGradientBrush(New Rectangle(0, 0, img.Width, img.Height), Color.Blue, Color.Blue, 1.2F, True)
g.DrawString(vnum, font, brush, 2, 2)
'VB.NET生成验证码中画图片的前景噪音点()
For ii As Integer = 0 To 100
Dim x As Integer = r.Next(img.Width)
Dim y As Integer = r.Next(img.Height)
img.SetPixel(x, y, Color.FromArgb(r.Next()))
Next
'画图片的边框线()
g.DrawRectangle(New Pen(Color.Silver),0, 0, img.Width - 1,img.Height - 1)
'在矩形内绘制字串(字串, 字体, 画笔颜色, 左上x.左上y)
PictureBox1.Image = img
PictureBox1.Refresh()
g.Dispose()
img.Dispose()
End Sub
在最后那个picturebox1.image=img时报错,去掉这行,则通过.
未处理 System.ArgumentException
Message=参数无效。
Source=System.Drawing
StackTrace:
在 System.Drawing.Image.get_Width()
在 System.Drawing.Image.get_Size()
在 System.Windows.Forms.PictureBox.ImageRectangleFromSizeMode(PictureBoxSizeMode mode)
在 System.Windows.Forms.PictureBox.OnPaint(PaintEventArgs pe)
在 System.Windows.Forms.Control.PaintWithErrorHandling(PaintEventArgs e, Int16 layer)
在 System.Windows.Forms.Control.WmPaint(Message& m)
在 System.Windows.Forms.Control.WndProc(Message& m)
在 System.Windows.Forms.Control.ControlNativeWindow.OnMessage(Message& m)
在 System.Windows.Forms.Control.ControlNativeWindow.WndProc(Message& m)
在 System.Windows.Forms.NativeWindow.DebuggableCallback(IntPtr hWnd, Int32 msg, IntPtr wparam, IntPtr lparam)
在 System.Windows.Forms.UnsafeNativeMethods.DispatchMessageW(MSG& msg)
在 System.Windows.Forms.Application.ComponentManager.System.Windows.Forms.UnsafeNativeMethods.IMsoComponentManager.FPushMessageLoop(IntPtr dwComponentID, Int32 reason, Int32 pvLoopData)
在 System.Windows.Forms.Application.ThreadContext.RunMessageLoopInner(Int32 reason, ApplicationContext context)
在 System.Windows.Forms.Application.ThreadContext.RunMessageLoop(Int32 reason, ApplicationContext context)
在 System.Windows.Forms.Application.Run(ApplicationContext context)
在 Microsoft.VisualBasic.ApplicationServices.WindowsFormsApplicationBase.OnRun()
在 Microsoft.VisualBasic.ApplicationServices.WindowsFormsApplicationBase.DoApplicationModel()
在 Microsoft.VisualBasic.ApplicationServices.WindowsFormsApplicationBase.Run(String[] commandLine)
在 验证码.My.MyApplication.Main(String[] Args) 位置 17d14f5c-a337-4978-8281-53493378c1071.vb:行号 81
在 System.AppDomain._nExecuteAssembly(RuntimeAssembly assembly, String[] args)
在 System.AppDomain.ExecuteAssembly(String assemblyFile, Evidence assemblySecurity, String[] args)
在 Microsoft.VisualStudio.HostingProcess.HostProc.RunUsersAssembly()
在 System.Threading.ThreadHelper.ThreadStart_Context(Object state)
在 System.Threading.ExecutionContext.Run(ExecutionContext executionContext, ContextCallback callback, Object state, Boolean ignoreSyncCtx)
在 System.Threading.ExecutionContext.Run(ExecutionContext executionContext, ContextCallback callback, Object state)
在 System.Threading.ThreadHelper.ThreadStart()
InnerException:
宽度和高度设置的多少，是不是<=0或者太大。 PictureBox1.Image = img
PictureBox1.Refresh()
g.Dispose()
img.Dispose() <---这里都dispose掉了当然报错了.
PictureBox1.Image = img 改成
PictureBox1.Image=New Bitmap(img)