picturebox image clearing

Question

i created a drawing apllication in my solution by this code.by this i can draw images in a picturebox and can to save. when i click the clearbutton the image on the picturebox is cleared but the problem is after clearing the image i can't draw any thing in the picturebox without the form's reload

dim mousepath as new system.drawing.drawing2d.graphicspath()

in pageload 
picturebox1.image=new bitmap(picturebox1.clientsize.height,picturebox1.clientsize.width)

picturebox1_paint(...)
myusercolor=(sysytem.drawing.color.black)
myalpha=100
using g as graphics=graphics.fromimage(picturebox1.image)
g.clear(color.white)
dim currentpen as pen=new pen(color.fromargb(myalpha,myusercolor),mypenwidth) g.drawpath(currentpen,mousepath) 

in mousedown
if e.button=mousebutton.left then
mousepath.startfigure()
end if

in mousemove
if e.button=mousebutton.left then
mousepath.addline(e.x,e.y,e.x,e.y)
end if
picturebox1.invalidate

clearbutton_click
picturebox1.image.dispose()
picturebox1.image=nothing

PROBLEM: if anyone knows the solution for this problem please help me.it's very important for me.thank you

Answer 1

when you clear, you set picturebox1.image=nothing, but then your Graphics object comes from that image. That's why it won't work. You have to set a new Bitmap when you clear like the first time :

picturebox1.image=new bitmap(picturebox1.clientsize.height,picturebox1.clientsize.width)
mousepath.Reset();