Colori graduali sfondo

Dim bmp As New Bitmap(Me.Width, Me.Height, _
System.Drawing.Imaging.PixelFormat.Format32bppPArgb)
Dim g As Graphics

If Dir("rettangolo.jpg") = "" Then
g = Graphics.FromImage(bmp)
Dim rect As New Rectangle(0, 0, Me.Width, Me.Height)

' sfondo sfumato

Dim lgb As New LinearGradientBrush _
(rect, Color.DarkBlue, Color.AliceBlue, LinearGradientMode.ForwardDiagonal)
g.FillRectangle(lgb, rect)

' salvo l'immagine su file JPG

bmp.Save("rettangolo.jpg", System.Drawing.Imaging.ImageFormat.Jpeg)
End If

' visualizzo l'immagine (su Windows Form)

Dim pic As New PictureBox
pic.Image = New Bitmap("rettangolo.jpg")
pic.Dock = DockStyle.Fill
Me.Controls.Add(pic)