Question

你好，我想实现在picturebox里面画线保存，但是画完线不能保存，因为画完之后不是image格式，我看见你说过

在picturebox里可以把线画在bitmap里然后可以把bitmap保存成图片格式对吗？？这个过程我想在vb.net2008中实现，看您能不能给我点提示呢？？？谢谢？？？

Answer 1

Private Sub PictureBox1_MouseClick(ByVal sender As Object, ByVal e As System.Windows.Forms.MouseEventArgs) Handles PictureBox1.MouseClick
Dim myBitmap As New Bitmap(640, 480)
Dim myGraphic As Graphics = Graphics.FromImage(myBitmap)
Dim mypen As New Pen(Color.Red, 1)
myGraphic.DrawEllipse(mypen, e.X, e.Y, 8, 8)
myGraphic.DrawLine(mypen, New Point(10, 10), New Point(100, 100))
PictureBox1.Image = myBitmap
mypen.Dispose()
myGraphic.Dispose()
End Sub

Private Sub Button1_Click(sender As System.Object, e As System.EventArgs) Handles Button1.Click
PictureBox1.Image.Save("c:\1.jpg", System.Drawing.Imaging.ImageFormat.Jpeg)
End Sub

追问

您的这个过程我大概明白，可是我画曲线，是在运行代码之后，通过鼠标移动事件来实现，得到曲线之后，我想把它保存成图片格式可以吗？？？

追答

可以啊，注意这两句：
Dim myBitmap As New Bitmap(640, 480)
Dim myGraphic As Graphics = Graphics.FromImage(myBitmap)
以后的绘画都在myGraphic里面完成，这样就可以保存了

追问

可是您看看我的代码！！就是无法实现保存到图片，只能看到 点 在picturebox 里？？无法保存，真的，您要是有条件的话，帮我看看，试试我的代码？？？我都纠结好久了，真的，太感谢了！

追答

可以了：
Public Class Form1
Dim preX As Single
Dim preY As Single
Private pStart, pEnd As Point
Dim ep As New Pen(Color.Red, 1)
Public image As Bitmap = Nothing
Dim g As Graphics
Private Sub Picturebox1_MouseDown(ByVal sender As Object, ByVal e As System.Windows.Forms.MouseEventArgs) Handles PictureBox1.MouseDown
Me.PictureBox1.Controls.Clear()
image = New Bitmap(Me.PictureBox1.Width, Me.PictureBox1.Height)
g = Graphics.FromImage(image)
g.Clear(Color.White)
'Me.PictureBox1.Image = DirectCast(image.Clone(), Bitmap)
If e.Button = Windows.Forms.MouseButtons.Left Then
pStart.X = e.X
pStart.Y = e.Y
End If

End Sub
Private Sub PictureBox1_MouseMove(ByVal sender As Object, ByVal e As System.Windows.Forms.MouseEventArgs) Handles PictureBox1.MouseMove
If e.Button = Windows.Forms.MouseButtons.Left Then
pEnd.X = e.X
pEnd.Y = e.Y
g.DrawLine(ep, pStart, pEnd)
ListBox1.Items.Add(pStart.X & " " & pStart.Y)
pStart = pEnd
End If
PictureBox1.Image = image

End Sub
Private Sub Button1_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button1.Click
PictureBox1.Image.Save("C:\123.jpeg")
End Sub
End Class