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Printing out Panel in C#

Again, I am asking a question about a USB Printer. This time however, the issue is more on the programming end of the spectrum.
I have a windows forms application in which I generate a receipt, which is then supposed to be sent to the printer. The Following things work: Generating the receipt, Sending the data to the printer.
The data however is only an empty strip of paper. I have the feeling that the Software is ignoring the Panel contents and just sends the empty panel to the printer.
The Sourcecode is as follows:
namespace MakeyMakey
{
public partial class Form1 : Form
{
public void Gridsettings()
{
GVReceipt.ScrollBars = ScrollBars.None;
GVReceipt.RowHeadersVisible = false;
GVReceipt.ColumnCount = 3;
GVReceipt.Columns[2].DefaultCellStyle.Alignment = DataGridViewContentAlignment.MiddleRight;
GVReceipt.CellBorderStyle = DataGridViewCellBorderStyle.None;
}
public Form1()
{
InitializeComponent();
pCompanyImage.SizeMode = PictureBoxSizeMode.StretchImage;
Bitmap Logo = new Bitmap(Bitmap.FromFile(#"C:/Users/manue/source/repos/MakeyMakey/MakeyMakey/logo.png"));
pCompanyImage.Image = MakeBW(Logo);
QRCodeGenerator qrGenerator = new QRCodeGenerator();
QRCodeData qrCodeData = qrGenerator.CreateQrCode("Hier kann so gut wie alles stehen", QRCodeGenerator.ECCLevel.Q);
QRCode qrCode = new QRCode(qrCodeData);
Bitmap qrCodeImage = qrCode.GetGraphic(20);
pQRCode.Image = qrCodeImage;
panel1.Height = GVProduct.Height + 220;
GVReceipt.Columns.Add("Name", "Name");
GVReceipt.Columns.Add("QTY", "QTY");
GVReceipt.Columns.Add("Price", "Price");
GVReceipt.Columns[0].Width = 50;
GVReceipt.Columns[1].Width = 15;
GVReceipt.Columns[2].Width = 50;
}
private void Form1_Load(object sender, EventArgs e)
{
}
private void label4_Click(object sender, EventArgs e)
{
}
private void textBox4_TextChanged(object sender, EventArgs e)
{
}
private void button1_Click(object sender, EventArgs e)
{
string[] row = new string[] {txtName.Text, txtQty.Text, txtPrice.Text };
GVReceipt.Rows.Add(row);
GVProduct.Rows.Add(row);
Gridsettings();
Calc();
txtName.Clear();
txtQty.Clear();
txtPrice.Clear();
txtName.Focus();
}
private void GVResize()
{
//MessageBox.Show(GVReceipt.Height.ToString());
GVReceipt.Height = GVReceipt.ColumnHeadersHeight + GVReceipt.RowCount * GVReceipt.Rows[0].Height;
//MessageBox.Show(GVReceipt.Height.ToString());
panel1.Height += GVReceipt.Rows[0].Height;
//MessageBox.Show(panel1.Height.ToString());
GVReceipt.ClearSelection();
Refresh();
}
private void GVReceipt_RowsAdded(object sender, DataGridViewRowsAddedEventArgs e)
{
}
private void GVReceipt_RowsRemoved(object sender, DataGridViewRowsRemovedEventArgs e)
{
panel1.Height = 389;
}
private void panel1_Paint(object sender, PaintEventArgs e)
{
}
public Bitmap MakeBW(Bitmap Map)
{
Bitmap newbmp = new Bitmap(Map.Width, Map.Height); // New image
for (int row = 0; row < Map.Width; row++) // Indicates row number
{
for (int column = 0; column < Map.Height; column++) // Indicate column number
{
var colorValue = Map.GetPixel(row, column); // Get the color pixel
var averageValue = ((int)colorValue.R + (int)colorValue.B + (int)colorValue.G) / 3; // get the average for black and white
newbmp.SetPixel(row, column, Color.FromArgb(averageValue, averageValue, averageValue)); // Set the value to new pixel
}
}
return newbmp;
}
public void Calc()
{
decimal total = 0;
for(int i = 0; i < GVReceipt.RowCount-1; i++)
{
total += Convert.ToDecimal(GVReceipt.Rows[i].Cells[2].Value) * Convert.ToDecimal(GVReceipt.Rows[i].Cells[1].Value);
}
//Console.WriteLine("HELLO");
//MessageBox.Show(total.ToString());
lbltotal.Text = total.ToString() + "€";
Refresh();
GVResize();
}
private void printDocument1_PrintPage(object sender, System.Drawing.Printing.PrintPageEventArgs e)
{
Print(panel1);
}
Bitmap MemoryImage;
PrintDocument printdoc1 = new PrintDocument();
PrintPreviewDialog previewdlg = new PrintPreviewDialog();
public void GetPrintArea(Panel pnl)
{
MemoryImage = new Bitmap(pnl.Width, pnl.Height);
Rectangle rect = new Rectangle(0, 0, pnl.Width, pnl.Height);
pnl.DrawToBitmap(MemoryImage, new Rectangle(0, 0, pnl.Width, pnl.Height));
}
public void printdoc1_PrintPage(object sender, PrintPageEventArgs e)
{
e.Graphics.DrawImage(MemoryImage, 0, 0);
}
public void Print(Panel pnl)
{
GetPrintArea(pnl);
printdoc1.PrinterSettings.PrinterName = "Generico";
printdoc1.DefaultPageSettings.PaperSize = new PaperSize("Custom", panel1.Width, panel1.Height);
previewdlg.Document = printdoc1;
previewdlg.ShowDialog();
printdoc1.Print();
}
private void btnPrinter_Click(object sender, EventArgs e)
{
printDocument1.Print();
GVProduct.Rows.Clear();
GVReceipt.Rows.Clear();
Calc();
}
private void GVReceipt_RowsAdded_1(object sender, DataGridViewRowsAddedEventArgs e)
{
//GVResize();
}
}
I have also included two images, one shows what the receipt looks like, the other what the print preview generated.
I'd highy appreciate any help on that topic.

Saving bitmap in a paint program

I am working on a MS paint like program that is programmed entirely in c#. It's very basic, but I have stumbled upon a problem. So I saw another SO post regarding MS paint mock ups. It was about how to save the end result as a .bmp file. I tried using the solutions and answers provided and it worked.
The file saved. However when it saved, it only saved the blank panel ( im making a forms app) . I have only seen one SO post that deals with this issue but I couldn't incorporate to allow the user to interact. The following is my code:
using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using System.Windows.Forms;
namespace Paint
{
public partial class Form1 : Form
{
Graphics g;
Pen p = new Pen(Color.Black, 1);
Point sp = new Point(0, 0);
Point ep = new Point(0, 0);
int k = 0;
public Form1()
{
InitializeComponent();
}
private void pictureBox2_Click(object sender, EventArgs e)
{
p.Color = red.BackColor;
default1.BackColor = red.BackColor;
}
private void blue_Click(object sender, EventArgs e)
{
p.Color = blue.BackColor;
default1.BackColor = blue.BackColor;
}
private void green_Click(object sender, EventArgs e)
{
p.Color = green.BackColor;
default1.BackColor = green.BackColor;
}
private void panel2_MouseDown(object sender, MouseEventArgs e)
{
sp = e.Location;
if (e.Button == MouseButtons.Left)
k = 1;
}
private void panel2_MouseUp(object sender, MouseEventArgs e)
{
k = 0;
}
private void panel2_MouseMove(object sender, MouseEventArgs e)
{
if (k == 1)
{
ep = e.Location;
g = panel2.CreateGraphics();
g.DrawLine(p, sp, ep);
}
sp = ep;
}
private void panel2_MouseLeave(object sender, EventArgs e)
{
k = 0; }
private void panel2_Paint(object sender, PaintEventArgs e)
{
}
private void button1_Click(object sender, EventArgs e)
{
SaveFileDialog dialog = new SaveFileDialog();
if (dialog.ShowDialog() == DialogResult.OK)
{
int width = Convert.ToInt32(panel2.Width);
int height = Convert.ToInt32(panel2.Height);
Bitmap bmp = new Bitmap(width, height);
panel2.DrawToBitmap(bmp, new Rectangle(0, 0, width, height));
bmp.Save(dialog.FileName, System.Drawing.Imaging.ImageFormat.Bmp);
}
}
}
}
So my question is... How do I Succesfully save a .bmp image in my c# forms app , as in how do i not make it save blank. Thanks in advance :)
edit
So I have tried the first answer and also im trying the ideas suggested by the individual in the comments and some how, instead of just saving a blank canvas. the application literally just saves a black image. Here is the code I ended up with. Where did I go wrong?
using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using System.Windows.Forms;
namespace Paint
{
public partial class Form1 : Form
{
Graphics g;
Graphics h;
Pen p = new Pen(Color.Black, 1);
Point sp = new Point(0, 0);
Point ep = new Point(0, 0);
int k = 0;
Bitmap bmp =null;
public Form1()
{
InitializeComponent();
}
private void pictureBox2_Click(object sender, EventArgs e)
{
p.Color = red.BackColor;
default1.BackColor = red.BackColor;
}
private void blue_Click(object sender, EventArgs e)
{
p.Color = blue.BackColor;
default1.BackColor = blue.BackColor;
}
private void green_Click(object sender, EventArgs e)
{
p.Color = green.BackColor;
default1.BackColor = green.BackColor;
}
private void panel2_MouseDown(object sender, MouseEventArgs e)
{
sp = e.Location;
if (e.Button == MouseButtons.Left)
k = 1;
}
private void panel2_MouseUp(object sender, MouseEventArgs e)
{
k = 0;
}
private void panel2_MouseMove(object sender, MouseEventArgs e)
{
if (k == 1)
{
ep = e.Location;
int width = Convert.ToInt32(panel2.Width);
int height = Convert.ToInt32(panel2.Height);
Bitmap bmp = new Bitmap(width, height);
g = Graphics.FromImage(bmp);
g.DrawLine(p, sp, ep);
h = panel2.CreateGraphics();
h.DrawLine(p, sp, ep);
}
sp = ep;
}
private void panel2_MouseLeave(object sender, EventArgs e)
{
k = 0; }
private void panel2_Paint(object sender, PaintEventArgs e)
{
}
private void button1_Click(object sender, EventArgs e)
{
SaveFileDialog dialog = new SaveFileDialog();
if (dialog.ShowDialog() == DialogResult.OK)
{
/*
Bitmap bmp = Bitmap.FromHbitmap(panel2.CreateGraphics().GetHdc());
panel2.DrawToBitmap(bmp, new Rectangle(0, 0, width, height));*/
int width = panel2.Width;
int height = Convert.ToInt32(panel2.Height);
if (bmp == null)
bmp = new Bitmap(width, height);
bmp.Save(dialog.FileName, System.Drawing.Imaging.ImageFormat.Jpeg);
}
}
}
}

Here is a revised version, pretty much what I told you in the comments..:
public partial class Form2 : Form
{
Graphics g;
Graphics h;
Pen p = new Pen(Color.Black, 1);
Point sp = new Point(0, 0);
Point ep = new Point(0, 0);
int k = 0;
Bitmap bmp =null;
public Form2()
{
InitializeComponent();
bmp = new Bitmap(panel2.ClientSize.Width, panel2.ClientSize.Height);
g = Graphics.FromImage(bmp);
g.Clear(panel2.BackColor);
}
private void pictureBox2_Click(object sender, EventArgs e)
{
p.Color = red.BackColor;
default1.BackColor = red.BackColor;
}
private void color_Click(object sender, EventArgs e)
{
Control ctl = sender as Control;
p.Color = ctl.BackColor;
default1.BackColor = ctl.BackColor;
}
private void panel2_MouseMove(object sender, MouseEventArgs e)
{
if (e.Button == MouseButtons.Left)
{
ep = e.Location;
g.DrawLine(p, sp, ep);
h = panel2.CreateGraphics();
h.DrawLine(p, sp, ep);
}
sp = ep;
}
private void panel2_MouseDown(object sender, MouseEventArgs e)
{
sp = e.Location;
}
private void button1_Click(object sender, EventArgs e)
{
SaveFileDialog dialog = new SaveFileDialog();
if (dialog.ShowDialog() == DialogResult.OK)
{
bmp.Save(dialog.FileName, System.Drawing.Imaging.ImageFormat.Jpeg);
}
}
}
A few notes:
I mapped all the clicks of the palette control into one.
I have eliminated the flag k by doing the button test in the move.
I have kept the cached Graphics g; this is usually not recommended, but as we keep drawing into one and the same bitmap is is ok.
I have remove all duplicate declaration of the bitmap bmp.
I don't know what the picturebox does, so I didn't touch the code.
Drawbacks of the soution:
Since you don''t keep track of all the moves you can't do a good undo.
Since all lines are drawn separately you can't get good results with broader and/or semi-transparent Pens because the overlapping endpoints will look bad.
For a better solution of simple doodeling see here and after you have studied it you can tackle the even better solution, which will allow you to use all sort of drawing tools here..

Use Graphics.GetHdc Method and save it like this:
Bitmap bitMap = Bitmap.FromHbitmap(g.GetHdc());
bitMap.Save(dialog.FileName, System.Drawing.Imaging.ImageFormat.Bmp);

How to connect pictureboxes with connecting line

first sorry for my English. I am programming application in windows forms. It is something like Packet Tracer. I have four buttons. When I click on them, they dynamicaly create pictureboxes with picture of Router or Switch,.... Each time I click on the button, new picture box(Switch or Router,...), is created. I can also move with this pictureboxes by mouse.
I need to create a button, which connects selected pictureboxes with line(Cable). This pictureboxes should be selected by click on them. It sholud be able to move with this objects(movable line).
Here is my code:
using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Linq;
using System.Text;
using System.Threading;
using System.Threading.Tasks;
using System.Windows.Forms;
namespace WindowsFormsApplication1
{
public partial class Form1 : Form
{
int a = 0;
int b = 0;
int c = 0;
int d = 0;
PictureBox[] picturebox = new PictureBox[100];
public Form1()
{
InitializeComponent();
}
private void router_Click(object sender, EventArgs e)
{
++a;
picturebox[a] = new PictureBox();
picturebox[a].Name = "picturebox" + a;
picturebox[a].Location = new Point(0 + (a-1) *100,100);
picturebox[a].Size = new Size(70, 70);
picturebox[a].BorderStyle = BorderStyle.None;
picturebox[a].SizeMode = PictureBoxSizeMode.StretchImage;
this.Controls.Add(picturebox[a]);
picturebox[a].Image = Image.FromFile(#"D:\\router.jpg");
picturebox[a].Refresh();
picturebox[a].MouseDown += new MouseEventHandler(picMouseDown);
picturebox[a].MouseMove += new MouseEventHandler(picMouseMove);
picturebox[a].MouseUp += new MouseEventHandler(picMouseUp);
}
private void Form1_Load(object sender, EventArgs e)
{
}
int x = 0;
int y = 0;
bool drag = false;
private void picMouseDown(object sender, MouseEventArgs e)
{
// Get original position of cursor on mousedown
x = e.X;
y = e.Y;
drag = true;
}
private void picMouseMove(object sender, MouseEventArgs e)
{
if (drag)
{
PictureBox pb = (PictureBox)sender;
// Get new position of picture
pb.Top += e.Y - y;
pb.Left += e.X - x;
pb.BringToFront();
}
}
private void picMouseUp(object sender, MouseEventArgs e)
{
drag = false;
}
private void switch1_Click(object sender, EventArgs e)
{
++b;
picturebox[b] = new PictureBox();
picturebox[b].Name = "picturebox" + b;
picturebox[b].Location = new Point(0 + (b - 1) * 100, 180);
picturebox[b].Size = new Size(70, 70);
picturebox[b].BorderStyle = BorderStyle.None;
picturebox[b].SizeMode = PictureBoxSizeMode.StretchImage;
this.Controls.Add(picturebox[b]);
picturebox[b].Image = Image.FromFile(#"D:\HP ProBook 450\Desktop\Grafika\switch1.png");
picturebox[b].Refresh();
picturebox[b].MouseDown += new MouseEventHandler(picMouseDown);
picturebox[b].MouseMove += new MouseEventHandler(picMouseMove);
picturebox[b].MouseUp += new MouseEventHandler(picMouseUp);
}
private void panel1_Paint(object sender, PaintEventArgs e)
{
}
private void pc_Click(object sender, EventArgs e)
{
++c;
picturebox[c] = new PictureBox();
picturebox[c].Name = "picturebox" + c;
picturebox[c].Location = new Point(0 + (c - 1) * 100, 260);
picturebox[c].Size = new Size(70, 70);
picturebox[c].BorderStyle = BorderStyle.None;
picturebox[c].SizeMode = PictureBoxSizeMode.StretchImage;
this.Controls.Add(picturebox[c]);
picturebox[c].Image = Image.FromFile(#"D:\HP ProBook 450\Desktop\pc.jpg");
picturebox[c].Refresh();
picturebox[c].MouseDown += new MouseEventHandler(picMouseDown);
picturebox[c].MouseMove += new MouseEventHandler(picMouseMove);
picturebox[c].MouseUp += new MouseEventHandler(picMouseUp);
}
private void server_Click(object sender, EventArgs e)
{
++d;
picturebox[d] = new PictureBox();
picturebox[d].Name = "picturebox" + d;
picturebox[d].Location = new Point(0 + (d - 1) * 100, 340);
picturebox[d].Size = new Size(70, 70);
picturebox[d].BorderStyle = BorderStyle.None;
picturebox[d].SizeMode = PictureBoxSizeMode.StretchImage;
this.Controls.Add(picturebox[d]);
picturebox[d].Image = Image.FromFile(#"D:\HP ProBook 450\Desktop\server.png");
picturebox[d].Refresh();
picturebox[d].MouseDown += new MouseEventHandler(picMouseDown);
picturebox[d].MouseMove += new MouseEventHandler(picMouseMove);
picturebox[d].MouseUp += new MouseEventHandler(picMouseUp);
}
}
}
THank you for your help.

You need to invalidate the parent when you add a picturebox or when you move a picturebox:
(picMouseMove and 4 times in the click handlers, it would be better to use 1 function)
Invalidate();
This is an example OnPaint, drawing lines between the pictureboxes as they are located in the Controls collection: (your picturebox array seems very weird, you always add controls at index 1, always overwriting the previous entry?! i'd suggest using a List if you need to keep a reference to them)
protected override void OnPaint(PaintEventArgs e)
{
base.OnPaint(e);
var pictureBoxes = Controls.OfType<PictureBox>().ToArray();
if (pictureBoxes.Length > 1)
{
for (int i = 1; i < pictureBoxes.Length; i++)
{
DrawLineBetween(e.Graphics, pictureBoxes[i - 1], pictureBoxes[i]);
}
}
}
This function can be used to draw a line between 2 of your boxes:
private void DrawLineBetween(Graphics g, PictureBox from, PictureBox to)
{
g.DrawLine(Pens.Black,
new Point(from.Left + from.Width / 2, from.Top + from.Height / 2),
new Point(to.Left + to.Width / 2, to.Top + to.Height / 2));
}
----- full sample below -----
I refactored your full example, and added the code above to start you off with a working example:
using System;
using System.Collections.Generic;
using System.Drawing;
using System.Windows.Forms;
namespace WindowsFormsApplication1
{
public partial class Form1 : Form
{
List<PictureBox> pictureboxes = new List<PictureBox>();
public Form1()
{
InitializeComponent();
}
private void AddPictureBox(string imagePath)
{
var pb = new PictureBox();
pb.Name = "picturebox" + pictureboxes.Count;
pb.Location = new Point(pictureboxes.Count * 100, 100);
pb.Size = new Size(70, 70);
pb.BorderStyle = BorderStyle.None;
pb.SizeMode = PictureBoxSizeMode.StretchImage;
this.Controls.Add(pb);
pb.Image = Image.FromFile(imagePath);
pb.Refresh();
pb.MouseDown += new MouseEventHandler(picMouseDown);
pb.MouseMove += new MouseEventHandler(picMouseMove);
pb.MouseUp += new MouseEventHandler(picMouseUp);
pictureboxes.Add(pb);
Invalidate();
}
private void router_Click(object sender, EventArgs e)
{
AddPictureBox(#"D:\\router.jpg");
}
private void Form1_Load(object sender, EventArgs e)
{
}
int x = 0;
int y = 0;
bool drag = false;
private void picMouseDown(object sender, MouseEventArgs e)
{
// Get original position of cursor on mousedown
x = e.X;
y = e.Y;
drag = true;
}
private void picMouseMove(object sender, MouseEventArgs e)
{
if (drag)
{
PictureBox pb = (PictureBox)sender;
// Get new position of picture
pb.Top += e.Y - y;
pb.Left += e.X - x;
pb.BringToFront();
Invalidate();
}
}
private void picMouseUp(object sender, MouseEventArgs e)
{
drag = false;
}
private void switch1_Click(object sender, EventArgs e)
{
AddPictureBox(#"D:\HP ProBook 450\Desktop\Grafika\switch1.png");
}
private void panel1_Paint(object sender, PaintEventArgs e)
{
}
private void pc_Click(object sender, EventArgs e)
{
AddPictureBox(#"D:\HP ProBook 450\Desktop\pc.jpg");
}
private void server_Click(object sender, EventArgs e)
{
AddPictureBox(#"D:\HP ProBook 450\Desktop\server.png");
}
protected override void OnPaint(PaintEventArgs e)
{
base.OnPaint(e);
if (pictureboxes.Count > 1)
{
var arr = pictureboxes.ToArray();
for (int i = 1; i < arr.Length; i++)
{
DrawLineBetween(e.Graphics, arr[i - 1], arr[i]);
}
}
}
private void DrawLineBetween(Graphics g, PictureBox from, PictureBox to)
{
g.DrawLine(Pens.Black,
new Point(from.Left + from.Width / 2, from.Top + from.Height / 2),
new Point(to.Left + to.Width / 2, to.Top + to.Height / 2));
}
}
}

I have two pictureBoxes in other sizes how can i make that when i click on one pictureBox it will draw a point on the smaller pictureBox?

This is my code but its not working not drawing points at all on pictureBox2.
public partial class Form1 : Form
{
private int counter;
private int pb1mouse_x;
private int pb1mouse_y;
private int pbsize_x;
private int pbsize_y;
public Form1()
{
InitializeComponent();
pbsize_x = pictureBox2.Width / pictureBox1.Width;
pbsize_y = pictureBox2.Height / pictureBox1.Height;
label4.Visible = false;
label5.Visible = false;
label6.Visible = false;
counter = 0;
pictureBox1.Load(#"d:\radar000075.png");
}
private void pictureBox1_MouseMove(object sender, MouseEventArgs e)
{
label4.Visible = true;
label4.Text = String.Format("X: {0}; Y: {1}", e.X, e.Y);
}
private void pictureBox1_MouseClick(object sender, MouseEventArgs e)
{
if (e.Button == MouseButtons.Left)
{
label5.Visible = true;
label5.Text = String.Format("X: {0}; Y: {1}", e.X, e.Y);
counter += 1;
label6.Visible = true;
label6.Text = counter.ToString();
pb1mouse_x = e.X;
pb1mouse_y = e.Y;
pb1mouse_x = pb1mouse_x * pbsize_x;
pb1mouse_y = pb1mouse_y * pbsize_y;
pictureBox2.Invalidate();
}
}
private void pictureBox2_Paint(object sender, PaintEventArgs e)
{
Pen p = new Pen(Color.Red);
var g = e.Graphics;
g.Clear(pictureBox1.BackColor);
g.DrawEllipse(p, new Rectangle(pb1mouse_x, pb1mouse_y, 10, 10));
}
}

You should be able to simply multiply by factors, i.e. smallBox.Width/largeBox.Width and smallBox.Height/largeBox.Height. Multiply the coordinates for the larger box by those factors and it will give you coordinates for the smaller box.
Edit:
This is what my code looks like:
using System;
using System.Collections.Generic;
using System.Drawing;
using System.Windows.Forms;
namespace PBoxes
{
public partial class Form1 : Form
{
private float xFactor, yFactor;
List<PointF> points = new List<PointF>();
public Form1()
{
InitializeComponent();
xFactor = (float)pictureBox2.Width / pictureBox1.Width;
yFactor = (float)pictureBox2.Height / pictureBox1.Height;
}
private void pictureBox1_MouseClick(object sender, MouseEventArgs e)
{
points.Add(new PointF(e.X * xFactor, e.Y * yFactor));
pictureBox2.Invalidate();
}
private void pictureBox2_Paint(object sender, PaintEventArgs e)
{
foreach (PointF pt in points)
{
e.Graphics.FillEllipse(Brushes.Red, pt.X, pt.Y, 3f, 3f);
}
}
private void pictureBox_SizeChanged(object sender, EventArgs e)
{
xFactor = (float)pictureBox2.Width / pictureBox1.Width;
yFactor = (float)pictureBox2.Height / pictureBox1.Height;
}
}
}

Draw on Panel, save as Bitmap

I'm trying to make a simple application where the user can draw on the Panel and save it to their computer as a bitmap. When I proceed to the save part, however, all I get is an empty (white) bitmap.
I've been browsing many other solutions and I am pretty sure I am saving the bitmap the correct way, so I am starting to wonder if my drawing process is incorrect. What exactly is wrong here?
public partial class Form1 : Form
{
SolidBrush brush;
Pen pen;
Point[] points = new Point[3];
Graphics display;
Bitmap bmap;
public Form1()
{
InitializeComponent();
display = panel1.CreateGraphics();
bmap = new Bitmap(panel1.Width, panel1.Height);
}
private void panel1_MouseDown(object sender, MouseEventArgs e)
{
brush = new SolidBrush(Color.Black);
pen = new Pen(Color.Black);
display.FillEllipse(brush, e.X, e.Y, 10, 10);
panel1.DrawToBitmap(bmap, new Rectangle(0, 0, panel1.Width, panel1.Height));
//this.Invalidate();
}
private void clearToolStripMenuItem_Click(object sender, EventArgs e)
{
Graphics display = panel1.CreateGraphics();
display.Clear(panel1.BackColor);
}
private void saveToolStripMenuItem_Click(object sender, EventArgs e)
{
bmap.Save(#"C:\Temp\Test.bmp");
}
}
EDIT
With this revision, I just get a black bmp and I don't even see elipses being created anymore on my screen. Although I did notice that if I put invalidate and Draw to bitmap back in the mousedown event, then the save button will save the last ellipse, while there is still nothing appearing on my screen.
private void panel1_MouseDown(object sender, MouseEventArgs e)
{
mousedown = true;
x = e.X;
y = e.Y;
}
private void panel1_Paint(object sender, PaintEventArgs e)
{
//Graphics g = e.Graphics;
if(mousedown==true)
{
brush = new SolidBrush(Color.Black);
pen = new Pen(Color.Black);
Graphics.FromImage(bmap).FillEllipse(brush, x, y, 10, 10);
panel1.Invalidate();
//panel1.DrawToBitmap(bmap, new Rectangle(0, 0, panel1.Width, panel1.Height));
//panel1.Invalidate();
}
}

As Hans did most of the work in his comment, here is how your code should probably look:
public partial class Form1 : Form {
Bitmap bmap;
public Form1() {
InitializeComponent();
bmap = new Bitmap(panel1.ClientWidth, panel1.ClientHeight);
panel1.MouseDown += panel1_MouseDown;
panel1.Paint += panel1_Paint;
}
void panel1_Paint(object sender, PaintEventArgs e) {
e.Graphics.DrawImage(bmap, Point.Empty);
}
void panel1_MouseDown(object sender, MouseEventArgs e) {
using (Graphics g = Graphics.FromImage(bmap)) {
g.FillEllipse(Brushes.Black, e.X, e.Y, 10, 10);
}
panel1.Invalidate();
}
private void clearToolStripMenuItem_Click(object sender, EventArgs e) {
using (Graphics g = Graphics.FromImage(bmap)) {
g.Clear(Color.White);
}
panel1.Invalidate();
}
private void saveToolStripMenuItem_Click(object sender, EventArgs e) {
bmap.Save(#"c:\temp\bmap.bmp");
}
}
CreateGraphics is just a temporary canvas, so you rarely, if ever, use that for drawing purposes, especially since you are trying to save an image.

This will works fine. I tested it and worked well
using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Drawing.Imaging;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using System.Windows.Forms;
namespace drawing
{
public partial class Form2 : Form
{
Graphics g;
bool startPaint = false;
int? initX = null;
int? initY = null;
bool drawSquare = false;
bool drawRectangle = false;
bool drawCircle = false;
public Form2()
{
InitializeComponent();
bmp = new Bitmap(panel1.ClientSize.Width, panel1.ClientSize.Height);
}
Bitmap bmp;
protected override void OnLoad(EventArgs e)
{
base.OnLoad(e);
}
void panel1_MouseMove(object sender, MouseEventArgs e)
{
if (startPaint)
{
using ( g = Graphics.FromImage(bmp))
{
// g.FillEllipse(Brushes.Black, new Rectangle(e.X, e.Y , 5, 5));
Pen p = new Pen(btn_PenColor.BackColor, float.Parse(cmb_PenSize.Text));
g.DrawLine(p, new Point(initX ?? e.X, initY ?? e.Y), new Point(e.X, e.Y));
initX = e.X;
initY = e.Y;
//g.DrawImage(bmp, new Rectangle(e.X - 4, e.Y - 4, 8, 8));
}
panel1.Invalidate();
}
}
private void pnl_Draw_MouseDown(object sender, MouseEventArgs e)
{
startPaint = true;
if (drawSquare)
{
//Use Solid Brush for filling the graphic shapes
SolidBrush sb = new SolidBrush(btn_PenColor.BackColor);
//setting the width and height same for creating square.
//Getting the width and Heigt value from Textbox(txt_ShapeSize)
g.FillRectangle(sb, e.X, e.Y, int.Parse(txt_ShapeSize.Text), int.Parse(txt_ShapeSize.Text));
//setting startPaint and drawSquare value to false for creating one graphic on one click.
startPaint = false;
drawSquare = false;
}
if (drawRectangle)
{
SolidBrush sb = new SolidBrush(btn_PenColor.BackColor);
//setting the width twice of the height
g.FillRectangle(sb, e.X, e.Y, 2 * int.Parse(txt_ShapeSize.Text), int.Parse(txt_ShapeSize.Text));
startPaint = false;
drawRectangle = false;
}
if (drawCircle)
{
SolidBrush sb = new SolidBrush(btn_PenColor.BackColor);
g.FillEllipse(sb, e.X, e.Y, int.Parse(txt_ShapeSize.Text), int.Parse(txt_ShapeSize.Text));
startPaint = false;
drawCircle = false;
}
}
private void pnl_Draw_MouseUp(object sender, MouseEventArgs e)
{
startPaint = false;
initX = null;
initY = null;
}
void panel1_Paint(object sender, PaintEventArgs e)
{
e.Graphics.DrawImage(bmp, Point.Empty);
}
private void button1_Click(object sender, EventArgs e)
{
bmp.Save("D://filename.jpg", ImageFormat.Png);
}
}
}