Question

我有一个图片框，它的输出与此类似：

e = New PrintPageEventArgs(PictureBox1.CreateGraphics, New Rectangle(New Point(25, 25), New Size(New Point(825, 1075))), e.PageBounds, e.PageSettings)

'Draw box
e.Graphics.DrawRectangle(Pens.Gray, 20, 30, e.PageBounds.Width - 100, e.PageBounds.Height - 130)

DrawnImage = PictureBox1.Image

我需要在Paint事件中对其进行更新：

Private Sub PictureBox1_Paint(sender As Object, e As PaintEventArgs) Handles PictureBox1.Paint

    PictureBox1.Image = DrawnImage 

End Sub

问题是DrawingImage为NULL。如何捕获图像？

Answer 1

我需要使用位图而不是从图片框创建图形对象。

有关完整的说明，请在此处查看：How do I repaint my picturebox when the picture disappears?

Dim b As New Bitmap(PictureBox1.Width, PictureBox1.Height)

e = New PrintPageEventArgs(Graphics.GraphicsFromImage(b), New Rectangle(New Point(25, 25), New Size(New Point(825, 1075))), e.PageBounds, e.PageSettings)

'Draw box
e.Graphics.DrawRectangle(Pens.Gray, 20, 30, e.PageBounds.Width - 100, e.PageBounds.Height - 130)

PictureBox1.Image = b

如何用绘制的内容重新粉刷图片框？

1 个答案: