C#•2mo ago

Windows Forms drawing not saving

When im drawing on the picturebox (pageImage) and im saving, the data is not saved

39 Replies

Silme94OP•2mo ago

how i create Graphics instance

g = pageImage.CreateGraphics();

g = pageImage.CreateGraphics();

private bool isDrawing = false;
private Point pos;
private Pen drawingPen;


private void PageImage_MouseDown(object sender, MouseEventArgs e)
{
    if (e.Button == MouseButtons.Left) 
    {
        isDrawing = true;
        pos.X = e.X;
        pos.Y = e.Y;
    }
}

private void PageImage_MouseDrawMove(object sender, MouseEventArgs e)
{
    if (isDrawing)
    {
        g.DrawLine(drawingPen, pos, e.Location);

        pos = e.Location;
    }
}

private void PageImage_MouseUp(object sender, MouseEventArgs e)
{
    if (e.Button == MouseButtons.Left)
    {
        isDrawing = false;


        Bitmap bitmap = new Bitmap(pageImage.Image);
        bitmap.Save(pageImage.ImageLocation);
    }
}

private bool isDrawing = false;
private Point pos;
private Pen drawingPen;


private void PageImage_MouseDown(object sender, MouseEventArgs e)
{
    if (e.Button == MouseButtons.Left) 
    {
        isDrawing = true;
        pos.X = e.X;
        pos.Y = e.Y;
    }
}

private void PageImage_MouseDrawMove(object sender, MouseEventArgs e)
{
    if (isDrawing)
    {
        g.DrawLine(drawingPen, pos, e.Location);

        pos = e.Location;
    }
}

private void PageImage_MouseUp(object sender, MouseEventArgs e)
{
    if (e.Button == MouseButtons.Left)
    {
        isDrawing = false;


        Bitmap bitmap = new Bitmap(pageImage.Image);
        bitmap.Save(pageImage.ImageLocation);
    }
}

look at PageImage_MouseUp event im able to draw on the window, but when it comes to save, it does not work

MonJamp•2mo ago

~~Does isDrawing ever get set to false?~~ nvm Can you clarify "does not work"? Does a bitmap image at least get created?

Silme94OP•2mo ago

the image does not change, it keep original and the drawing does not affect like on the picturebox i see that i drew but when it comes to save it to a file the changes dont applies

MonJamp•2mo ago

When you are drawing, I believe the drawing data gets saved to the g object. When you save, it looks like you're just saving the page but that doesn't contain the data which you drew Maybe I'm wrong?

Silme94OP•2mo ago

i think so, but then how can i save the Graphics too?

MonJamp•2mo ago

Are you able to convert g to a bitmap or image object?

Silme94OP•2mo ago

uh i think

Silme94OP•2mo ago

https://stackoverflow.com/questions/1535730/convert-graphics-object-to-bitmap-object

Stack Overflow

Convert graphics object to bitmap object

How can I convert graphics object to bitmap object using C#?

MonJamp•2mo ago

https://learn.microsoft.com/en-us/dotnet/api/system.drawing.graphics?view=windowsdesktop-7.0

Graphics Class (System.Drawing)

Encapsulates a GDI+ drawing surface. This class cannot be inherited.

MonJamp•2mo ago

Check out the documentation, I'm sure one of the methods will help you out here The second answer in the stackoverflow page sounds promising: Bitmap bmp = new Bitmap(100,100,graphics);

Silme94OP•2mo ago

@MonJamp it just save a blank page Bitmap bitmap = new Bitmap(pageImage.Width, pageImage.Height, g); without the drawing man idk thank you for trying to help

MonJamp•2mo ago

For sure There are many different ways you could go about to implement this, I'm not too familiar with how to use the Graphics object but maybe the best approach would be to save the pixel data in an array as you're drawing - just an idea Good luck

Nasdack•2mo ago

You're saving pageImage not its Graphics created instance called g

MonJamp•2mo ago

Ye that's what we figured out before, the difficulty is saving the Graphics object to a bitmap And combining both the pageImage and g

Silme94OP•2mo ago

then how can i combine these 2 instance to save them in one file?

Nasdack•2mo ago

Try this Create a new Bitmap that has your image new Bitmap(pageImage.Image) Create the Graphics from this bitmap Graphics.FromImage(bitmap) Set pageImage.Image = bitmap Draw as you normally would, but call pageImage.Invalidate() at the end so it can display changes Then on save you want to bitmap.Save(pageImage.ImageLocation, ...)

Silme94OP•2mo ago

@Nasdack "A generic error occurred in GDI+" when the mouseUp event if fired :

drawingBitmap = new Bitmap(pageImage.ImageLocation);
//g = pageImage.CreateGraphics();
g = Graphics.FromImage(drawingBitmap);
pageImage.Image = drawingBitmap;

drawingBitmap = new Bitmap(pageImage.ImageLocation);
//g = pageImage.CreateGraphics();
g = Graphics.FromImage(drawingBitmap);
pageImage.Image = drawingBitmap;

private void PageImage_MouseDown(object sender, MouseEventArgs e)
{
    if (e.Button == MouseButtons.Left) 
    {
        isDrawing = true;
        pos.X = e.X;
        pos.Y = e.Y;
    }
}

private void PageImage_MouseDrawMove(object sender, MouseEventArgs e)
{
    if (isDrawing)
    {
        g.DrawLine(drawingPen, pos, e.Location);

        pos = e.Location;

        pageImage.Invalidate();
    }
}

private void PageImage_MouseUp(object sender, MouseEventArgs e)
{
    if (e.Button == MouseButtons.Left)
    {
        isDrawing = false;

        drawingBitmap.Save(pageImage.ImageLocation);
    }
}

private void PageImage_MouseDown(object sender, MouseEventArgs e)
{
    if (e.Button == MouseButtons.Left) 
    {
        isDrawing = true;
        pos.X = e.X;
        pos.Y = e.Y;
    }
}

private void PageImage_MouseDrawMove(object sender, MouseEventArgs e)
{
    if (isDrawing)
    {
        g.DrawLine(drawingPen, pos, e.Location);

        pos = e.Location;

        pageImage.Invalidate();
    }
}

private void PageImage_MouseUp(object sender, MouseEventArgs e)
{
    if (e.Button == MouseButtons.Left)
    {
        isDrawing = false;

        drawingBitmap.Save(pageImage.ImageLocation);
    }
}

when it tries to save the image

Nasdack•2mo ago

drawingBitmap = new Bitmap(pageImage.ImageLocation); can that be .Image instead

Silme94OP•2mo ago

i dont think so cause im setting the with with ImageLocation

Silme94OP•2mo ago

ive found this idk this ay workshttps://www.youtube.com/watch?v=bp9PzpGZsWA

Elsayed Hamdy

YouTube

Solving : A generic error occurred in GDI+

github https://github.com/ElsayedHamdy/MyWork/tree/master/dot_NET_Problems/GDI_ERROR

Nasdack•2mo ago

this error happens when the file is in use try to save to a different location

Silme94OP•2mo ago

already tried

Nasdack•2mo ago

using g = ... this would dispose it but that's not what we want

Silme94OP•2mo ago

im not using "using" ?

Nasdack•2mo ago

pageImage.Image?.Dispose(); try this before saving

Silme94OP•2mo ago

same error and its not even drawing anything in the two case

Nasdack•2mo ago

if you draw nothing happens?

Silme94OP•2mo ago

when i move the cursor its not drawingbut when i up the mouse it says the error the lines are not drawing but i think its bc of the errors u know

Nasdack•2mo ago

https://learn.microsoft.com/en-us/dotnet/desktop/winforms/advanced/how-to-create-graphics-objects-for-drawing?view=netframeworkdesktop-4.8

How to: Create Graphics Objects for Drawing - Windows Forms .NET Fr...

Learn now to create a Graphic object that you need to draw lines and shapes, render text, or display and manipulate images with GDI+.

Nasdack•2mo ago

I found this and if you follow it through and rewrite your code it should be errorless

Silme94OP•2mo ago

i dont see nothing wrong

Silme94OP•2mo ago

message.txt

Silme94OP•2mo ago

this is full code, read the class constructor and the end of the code @Nasdack do you see anything wrong ?

Nasdack•2mo ago

the error has to do with saving the file nothing else make sure you're saving to another location

Silme94OP•2mo ago

nah not the issue

private void PageImage_MouseUp(object sender, MouseEventArgs e)
{
    if (e.Button == MouseButtons.Left)
    {
        isDrawing = false;

        //MemoryStream ms = new MemoryStream();
        pageImage.Image?.Dispose();
        drawingBitmap.Save("C:\\test.png"); //pageImage.ImageLocation);

        
    }
}

private void PageImage_MouseUp(object sender, MouseEventArgs e)
{
    if (e.Button == MouseButtons.Left)
    {
        isDrawing = false;

        //MemoryStream ms = new MemoryStream();
        pageImage.Image?.Dispose();
        drawingBitmap.Save("C:\\test.png"); //pageImage.ImageLocation);

        
    }
}

Nasdack•2mo ago

what's the issue send a screenshot with details

Silme94OP•2mo ago

@Nasdack

Nasdack•2mo ago

Scrap this codebase It's a mess Just follow the tutorial here

Gaming

Programming

Windows Forms drawing not saving

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