How to save pictureBox to a file ?

[user]

Hello
I tried:
pictureBox1.Ima ge.Save("file.s av");

compiled, but when i run i receive errors:
Additional information: Object reference not set to an instance of an
object.

Why ?

Thanx
Michal

[Scatropolis]

What you want to do is instead of drawing on the pictureBox you want to create
an Image, draw invisibly on that, then put the Image on the pictureBox.
pictureBox1.Ima ge = new Bitmap(pictureB ox1.Width, pictureBox1.Hei ght);
Image bmp = pictureBox1.Ima ge;
Graphics g = Graphics.FromIm age(bmp);

//Edit bmp...any drawing goes here using 'g'
g.FillRectangle (new SolidBrush(Colo r.White), 0, 0, pictureBox1.Wid th,
pictureBox1.Hei ght);
for(int I=0; I < pictureBox1.Wid th; I+)
g.DrawLine(new Pen(Color.Black ), pictureBox1.Wid th - I, 0, 0, I);

//Display bmp
pictureBox1.Ima ge = bmp;

then to save you could save the pictureBox.Imag e or you could make bmp public
and save that directly either would work, the second probably would be better.

Hope that answers your question.
On 15/04/2004 us**@domain.inv alid wrote:

Hello
I tried:
pictureBox1.Im age.Save("file. sav");

compiled, but when i run i receive errors:
Additional information: Object reference not set to an instance of an
object.

Why ?

Thanx
Michal

[ivan]

This piece of code works fine for me either:

// Code:
private void buttonSave_Clic k(object sender, System.EventArg s e)
{
SaveFileDialog save = new SaveFileDialog( );
save.Filter = "Bitmap files (*.bmp)|*.bmp|J PG files (*.jpg)|*.jpg|G IF
files (*.gif)|*.gif|A ll files (*.*)|*.*";
save.FilterInde x = 4;
save.RestoreDir ectory = true;

if(save.ShowDia log() == DialogResult.OK )
{
myPictureBox.Im age.Save(save.F ileName);
}
}

[user]

Hello

That's strange, i have identical code and still the same error:

SaveFileDialog save = new SaveFileDialog( );
save.Filter = "Bitmap files (*.bmp)|*.bmp|J PG files (*.jpg)|*.jpg|G IF
files (*.gif)|*.gif|A ll files (*.*)|*.*";
save.FilterInde x = 4;
save.RestoreDir ectory = true;
if(save.ShowDia log() == DialogResult.OK )
{/*LINE 100: HERE IS THE PROBLEM*/
pictureBox1.Ima ge.Save(save.Fi leName);
}

when i check in line 100 i receive that pictureBox1.Ima ge==null,
but how is it possible ?? Durring saving i see my paintings
on that pictureBox.

Thanx
Michal

[user]

i found that only the second method described by Scatropolis works for
me fine. I wonder why...

[Scatropolis]

hmm for some reason it didn't paste correctly.....

On 15/04/2004 "Scatropoli s" <ch*****@frayed .net> wrote:

What you want to do is instead of drawing on the pictureBox you want to createan Image, draw invisibly on that, then put the Image on the pictureBox.
pictureBox1.Im age = new Bitmap(pictureB ox1.Width, pictureBox1.Hei ght);
Image bmp ictureBox1.Imag e;
Graphics g raphics.FromIma ge(bmp);

//Edit bmp...any drawing goes here using 'g'
g.FillRectangl e(new SolidBrush(Colo r.White), 0, 0, pictureBox1.Wid th,
pictureBox1.He ight);
for(int I I < pictureBox1.Wid th; I+)
g.DrawLine(new Pen(Color.Black ), pictureBox1.Wid th - I, 0, 0, I);

//Display bmp
pictureBox1.Im age mp;

this line should be

picturebox1.Ima ge = bmp;

[Scatropolis]

Ack it seems when I pasted it letters got deleted. trying to change everything

pictureBox1.Ima ge = new Bitmap(pictureB ox1.Width, pictureBox1.Hei ght);
Image bmp = PictureBox1.Ima ge;
Graphics g = Graphics.FromIm age(bmp);

//Edit bmp...any drawing goes here using 'g'
g.FillRectangle (new SolidBrush(Colo r.White), 0, 0, pictureBox1.Wid th,
pictureBox1.Hei ght);
for(int I I < pictureBox1.Wid th; I+)
g.DrawLine(new Pen(Color.Black ), pictureBox1.Wid th - I, 0, 0, I);

//Display bmp
pictureBox1.Ima ge = bmp;

there....that's kinda weird, sorry

[Scatropolis]

When you draw on a pictureBox it is not saved into the image. I don't think
it's even saved anywhere. Which is why when it gets minimized or covered over
it's erased.

On 15/04/2004 us**@domain.inv alid wrote:

i found that only the second method described by Scatropolis works for
me fine. I wonder why...