如何在图片框上绘制而不丢失最小化后的内容，vb.net？

Public Class DoubleBufferedPictureBox
    Inherits PictureBox

    Public Sub New()
        Me.DoubleBuffered = True
    End Sub

End Class

Dim picturebox As New DoubleBufferedPictureBox()
picturebox.SizeMode = PictureBoxSizeMode.Zoom
' 设置其他属性和位置
Me.Controls.Add(picturebox)

Private Sub Form1_Paint(sender As Object, e As PaintEventArgs) Handles MyBase.Paint
    ' 创建一个Bitmap对象
    Dim bmp As New Bitmap(picturebox.Width, picturebox.Height)
    ' 绘制需要绘制的内容到Bitmap对象上

    Using g As Graphics = Graphics.FromImage(bmp)
        ' 绘制内容到Bitmap对象上
        ' 例如，可以绘制一个矩形
        Dim rect As New Rectangle(10, 10, 100, 100)
        g.FillRectangle(Brushes.Red, rect)
    End Using

    ' 将Bitmap对象绘制到DoubleBufferedPictureBox上
    picturebox.Image = bmp
End Sub