Partial screenshot with rectangle of selection c# - c#

I'm trying to take a partial screenshot of the screen and put it in a picturebox. The user has to draw a rectangle and then i have to get the portion inside the rectangle.
protected override void OnMouseDown(MouseEventArgs e)
{
mRect = new Rectangle(e.X, e.Y, 0, 0);
this.Invalidate();
}
protected override void OnMouseMove(MouseEventArgs e)
{
if( e.Button == MouseButtons.Left)
{
mRect = new Rectangle(mRect.Left, mRect.Top, e.X - mRect.Left, e.Y - mRect.Top);
this.Invalidate();
}
}
protected override void OnPaint(PaintEventArgs e)
{
using(Pen pen = new Pen(Color.Red, 1))
{
e.Graphics.DrawRectangle(pen, mRect);
}
}
With this code i can draw a recangle, but i don't know how to do the screenshot. Maybe with the fonction CopyToScreen?
If someone have an idea?
Thanks!

Here is some code I use - it grabs the whole desktop
public static Bitmap GetScreenAsBmp()
{
int min_x=0, max_x=0, min_y=0, max_y=0;
foreach (Screen s in Screen.AllScreens)
{
min_x = System.Math.Min(min_x, s.Bounds.Left);
max_x = System.Math.Max(max_x, s.Bounds.Right);
min_y = System.Math.Min(min_y, s.Bounds.Top);
max_y = System.Math.Max(max_y, s.Bounds.Bottom);
}
Bitmap bmp = new Bitmap(max_x - min_x, max_y - min_y);
Graphics dst_dc = Graphics.FromImage(bmp);
dst_dc.CopyFromScreen(min_x, min_y, 0, 0, new Size(max_x - min_x, max_y - min_y));
dst_dc.Dispose();
return bmp;
}

This is a complete solution for the problem.
It is triggered by a Button and then:
creates and styles a second Form which
is transparent without borders etc and fills the screen
has all events needed to draw a Rectangle
copies the screen after the rectangle is drawn, i.e. after the MouseUp
and copies the Bitmap into the Image of a PictureBox on the 1st Form.
Finally it closes the 2nd form. During the screencopy process both windows are hidden, so you can grab the screen itself with all its content.
Note that many video overlays can't be captured this way!
Note that this code always captures from the 1st screen!
For best usability the users should somehow be informed that he is expected to draw the frame after the Button is pressed and the window has disappeared!
To use it simply add a Button and a PictureBox to your Form..
public partial class Form1 : Form
{
public Form1()
{
InitializeComponent();
}
Form form2;
Point MD = Point.Empty;
Rectangle rect = Rectangle.Empty;
private void button2_Click(object sender, EventArgs e)
{
Hide();
form2 = new Form();
form2.BackColor = Color.Wheat;
form2.TransparencyKey = form2.BackColor;
form2.ControlBox = false;
form2.MaximizeBox = false;
form2.MinimizeBox = false;
form2.FormBorderStyle = FormBorderStyle.None;
form2.WindowState = FormWindowState.Maximized;
form2.MouseDown += form2_MouseDown;
form2.MouseMove += form2_MouseMove;
form2.Paint += form2_Paint;
form2.MouseUp += form2_MouseUp;
form2.Show();
}
void form2_MouseDown(object sender, MouseEventArgs e)
{
MD = e.Location;
}
void form2_MouseMove(object sender, MouseEventArgs e)
{
if (e.Button !=MouseButtons.Left) return;
Point MM = e.Location;
rect = new Rectangle(Math.Min(MD.X, MM.X), Math.Min(MD.Y, MM.Y),
Math.Abs(MD.X - MM.X), Math.Abs(MD.Y - MM.Y));
form2.Invalidate();
}
void form2_Paint(object sender, PaintEventArgs e)
{
e.Graphics.DrawRectangle(Pens.Red, rect);
}
void form2_MouseUp(object sender, MouseEventArgs e)
{
form2.Hide();
Screen scr = Screen.AllScreens[0];
Bitmap bmp = new Bitmap(rect.Width, rect.Height);
using (Graphics G = Graphics.FromImage(bmp))
{
G.CopyFromScreen(rect.Location, Point.Empty, rect.Size,
CopyPixelOperation.SourceCopy);
pictureBox1.Image = bmp;
}
form2.Close();
Show();
}
}

Related

How to copy from screen 9 different Images using C#?

I'm doing a school project using C# in which I designed a Form in C# that I can draw on and now I need to copy what I draw into a 9 different Images and save them. So far, I tried using the copy from screen function like that:
Size s = this.Size;
Bitmap memoryImage = new Bitmap(s.Width, s.Height, this.CreateGraphics());
Graphics.FromImage(memoryImage).CopyFromScreen(this.Location.X, this.Location.Y, 0, 0, s);
memoryImage.Save(#"C:\Users\omerm\Desktop\projectFinals\ProjectFiles\C-Sharp\Drawing\WinFormsApp1\Digits\1.jpg");
My problem is that the image I get from this code includes parts of my screen that aren't part of my Form. And I also need to copy 9 different images who are fractions of this one instead of just the one and make sure those 9 are around the same shape(squares). does anyone know how to do that?
I'm terrible at explaining this so think that I need to take the original image and cut into 9 like in a tic tac toe board and save each one of them as a different image in the shape of squares instead of the original.
full code:
namespace WinFormsApp1
{
public partial class Form1 : Form
{
Pen Pen = new Pen(Color.Black, 2);
int pX, pY;
Graphics g;
public object MemoryImage { get; private set; }
public Form1()
{
InitializeComponent();
}
private void Form1_Load(object sender, EventArgs e)
{
}
private void pictureBox1_MouseDown(object sender, MouseEventArgs e)
{
pX = e.X;
pY = e.Y;
}
private void pictureBox1_MouseMove(object sender, MouseEventArgs e)
{
if (e.Button == MouseButtons.Left)
{
Graphics g = pictureBox1.CreateGraphics();
g.DrawLine(Pen, pX, pY, e.X, e.Y);
pX = e.X;
pY = e.Y;
}
}
private void button1_Click(object sender, EventArgs e)
{
Size s = this.Size;
Bitmap memoryImage = new Bitmap(s.Width, s.Height, this.CreateGraphics());
Graphics.FromImage(memoryImage).CopyFromScreen(this.Location.X, this.Location.Y, 0, 0, s);
memoryImage.Save(#"C:\Users\omerm\Desktop\projectFinals\ProjectFiles\C-Sharp\Drawing\WinFormsApp1\Digits\1.jpg");
}
private void ChooseColor(object sender, EventArgs e)
{
Pen.Color = ((PictureBox)sender).BackColor;
}
}
}
Tried looking online but what I look for is really specific.
Here's an example of persisting the data in a structure and drawing it in the Paint() event. Additionally, I've demonstrated how to tell the PictureBox to draw itself instead of copying the screen:
public partial class Form1 : Form
{
public Form1()
{
InitializeComponent();
}
private List<Point> curSquiggle;
private List<List<Point>> Squiggles = new List<List<Point>>();
private void pictureBox1_MouseDown(object sender, MouseEventArgs e)
{
if (e.Button == MouseButtons.Left)
{
curSquiggle = new List<Point>();
curSquiggle.Add(e.Location);
Squiggles.Add(curSquiggle);
}
}
private void pictureBox1_MouseMove(object sender, MouseEventArgs e)
{
if (e.Button == MouseButtons.Left)
{
curSquiggle.Add(e.Location);
pictureBox1.Invalidate();
}
}
private void pictureBox1_Paint(object sender, PaintEventArgs e)
{
foreach(List<Point> squiggle in Squiggles)
{
e.Graphics.DrawLines(Pens.Black, squiggle.ToArray());
}
}
private void button1_Click_1(object sender, EventArgs e)
{
Bitmap bmp = new Bitmap(pictureBox1.ClientRectangle.Width, pictureBox1.ClientRectangle.Height);
pictureBox1.DrawToBitmap(bmp, pictureBox1.ClientRectangle);
// Do something with the bmp, like display it in another form:
Form frm = new Form();
frm.AutoSize = true;
PictureBox pb = new PictureBox();
pb.SizeMode = PictureBoxSizeMode.AutoSize;
pb.Image = bmp;
pb.Location = new Point(0, 0);
frm.Controls.Add(pb);
frm.Show();
}
}
Example run:
Here's a different version of the save code which splits the main picture into 9 pieces:
private void button1_Click_1(object sender, EventArgs e)
{
Bitmap bmp = new Bitmap(pictureBox1.ClientRectangle.Width, pictureBox1.ClientRectangle.Height);
pictureBox1.DrawToBitmap(bmp, pictureBox1.ClientRectangle);
int cols = 3;
int rows = 3;
int cellWidth = bmp.Width / cols;
int cellHeight = bmp.Height / rows;
Rectangle destRect = new Rectangle(0, 0, cellWidth, cellHeight);
List<Bitmap> cells = new List<Bitmap>();
for(int r=0; r<rows; r++)
{
for(int c=0; c<cols; c++)
{
Bitmap cell = new Bitmap(cellWidth, cellHeight);
Rectangle srcRect = new Rectangle(c * cellWidth, r * cellHeight, cellWidth, cellHeight);
using (Graphics g = Graphics.FromImage(cell))
{
g.DrawImage(bmp, destRect, srcRect, GraphicsUnit.Pixel);
}
cells.Add(cell);
}
}
foreach(Bitmap cell in cells)
{
Form frm = new Form();
frm.AutoSize = true;
frm.AutoSizeMode = AutoSizeMode.GrowAndShrink;
PictureBox pb = new PictureBox();
pb.SizeMode = PictureBoxSizeMode.AutoSize;
pb.Image = cell;
pb.Location = new Point(0, 0);
frm.Controls.Add(pb);
frm.Show();
}
}
Splitting into nine pieces:

Paint Drawline Image into Picturebox Image

In my Form, I have 2 picturebox controls. I loaded a blue background image on pictureBox1 and left pictureBox2 control alone. With the code below I'm able to draw arrows on top of my picturebox1 image.
Goal: On my pictureBox1_MouseUp event I want to add all the arrows which I drew on pictureBox1 to pictureBox2.
Issue: The problem is on my pictureBox1_MouseUp event when I wrote pictureBox2.Image = pictureBox1.Imageit doesn't add the painted arrow which I drew on pictureBox1. It only adds the pictureBox1 image that I assigned in my form load event.
private bool isMoving = false;
private Point mouseDownPosition = Point.Empty;
private Point mouseMovePosition = Point.Empty;
private List<Tuple<Point, Point>> lines = new List<Tuple<Point, Point>>();
Pen _Pen;
private void pictureBox1_Paint(object sender, PaintEventArgs e)
{
if (isMoving)
{
if (pictureBox1.Image == null) e.Graphics.Clear(Color.White);
// Add this line for high quality drawing:
e.Graphics.SmoothingMode = SmoothingMode.HighQuality;
AdjustableArrowCap bigArrow = new AdjustableArrowCap(5, 5);
_Pen = new Pen(Color.IndianRed, 3);
_Pen.CustomEndCap = bigArrow;
e.Graphics.DrawLine(_Pen, mouseDownPosition, mouseMovePosition);
_Pen.Dispose();
}
}
private void pictureBox1_MouseDown(object sender, MouseEventArgs e)
{
isMoving = true;
mouseDownPosition = e.Location;
}
private void pictureBox1_MouseMove(object sender, MouseEventArgs e)
{
if (isMoving)
{
mouseMovePosition = e.Location;
pictureBox1.Invalidate();
}
}
private void pictureBox1_MouseUp(object sender, MouseEventArgs e)
{
if (isMoving)
{
lines.Add(Tuple.Create(mouseDownPosition, mouseMovePosition));
}
isMoving = false;
pictureBox2.Image = pictureBox1.Image;
}
Test 1: (Changed pictureBox1_Paint code)
With this code, it draws the arrow on pictureBox2, but it looks like it is drawing multiple arrows.
if (isMoving)
{
if (pictureBox1.Image == null) e.Graphics.Clear(Color.White);
// Add this line for high quality drawing:
e.Graphics.SmoothingMode = SmoothingMode.HighQuality;
AdjustableArrowCap bigArrow = new AdjustableArrowCap(5, 5);
_Pen = new Pen(Color.IndianRed, 3);
Bitmap BitImg = (Bitmap)pictureBox1.Image;
_Pen.CustomEndCap = bigArrow;
using (var graphics = Graphics.FromImage(BitImg))
{
graphics.DrawLine(_Pen, mouseDownPosition, mouseMovePosition);
}
pictureBox1.Image = BitImg;
_Pen.Dispose();
}
Test 2: (I took the code from the paint event and pasted it MouseMove Event with some modifications. This uses too much memory and it doesn't draw on pictureBox1 but the arrow is now visible in pictureBox2)
private void pictureBox1_MouseMove(object sender, MouseEventArgs e)
{
if (isMoving)
{
mouseMovePosition = e.Location;
if (isMoving)
{
AdjustableArrowCap bigArrow = new AdjustableArrowCap(5, 5);
_Pen = new Pen(Color.IndianRed, 3);
BitImg = new Bitmap(pictureBox1.Image);
_Pen.CustomEndCap = bigArrow;
using (var graphics = Graphics.FromImage(BitImg))
{
graphics.SmoothingMode = SmoothingMode.HighQuality;
graphics.DrawLine(_Pen, mouseDownPosition, mouseMovePosition);
}
_Pen.Dispose();
}
pictureBox1.Invalidate();
}
}
Draw all lines to pictureBox1:
Draw only last line to pictureBox1:
In pictureBox2 control, add Paint event to pictureBox2_Paint.
I suggest you make pen and cap global varriable:
// Make pen and cap global varriable to boost the perfomane.
// Create and delete them each draw will cost alot of CPU
Pen pen = new Pen(Color.IndianRed, 3);
AdjustableArrowCap bigArrow = new AdjustableArrowCap(5, 5);
In Form1() event, add this line:
pen.CustomEndCap = bigArrow;
and do as following:
public partial class Form1 : Form
{
private bool isMoving = false;
private Point mouseDownPosition = Point.Empty;
private Point mouseMovePosition = Point.Empty;
private List<Tuple<Point, Point>> lines = new List<Tuple<Point, Point>>();
public Form1()
{
InitializeComponent();
pen.CustomEndCap = bigArrow;
}
private void pictureBox1_MouseDown(object sender, MouseEventArgs e)
{
isMoving = true;
mouseDownPosition = e.Location;
}
private void pictureBox1_MouseMove(object sender, MouseEventArgs e)
{
if (isMoving)
{
mouseMovePosition = e.Location;
pictureBox1.Invalidate();
}
}
private void pictureBox1_MouseUp(object sender, MouseEventArgs e)
{
if (isMoving)
{
lines.Add(Tuple.Create(mouseDownPosition, mouseMovePosition));
pictureBox2.Invalidate();
}
isMoving = false;
}
private void pictureBox1_Paint(object sender, PaintEventArgs e)
{
if (isMoving)
{
if ((sender as PictureBox).Image == null) e.Graphics.Clear(Color.White);
// Add this line for high quality drawing:
e.Graphics.SmoothingMode = SmoothingMode.HighQuality;
e.Graphics.DrawLine(pen, mouseDownPosition, mouseMovePosition);
// If you want draw all previous lines here, add bellow code:
//foreach (var line in lines)
//{
// e.Graphics.DrawLine(pen, line.Item1, line.Item2);
//}
}
}
private void pictureBox2_Paint(object sender, PaintEventArgs e)
{
if ((sender as PictureBox).Image == null) e.Graphics.Clear(Color.White);
e.Graphics.SmoothingMode = SmoothingMode.HighQuality;
foreach (var line in lines)
{
e.Graphics.DrawLine(pen, line.Item1, line.Item2);
}
}
}
Above code draw lines to PictureBox control, not to image, this allow you remove some lines or clear all lines you draw to picturebox if you want later.
If you want draw directly to image, things event much easier, you don't need pictureBox2_Paint at all:
private void pictureBox1_MouseUp(object sender, MouseEventArgs e)
{
if (isMoving)
{
// You event don't need this line
//lines.Add(Tuple.Create(mouseDownPosition, mouseMovePosition));
if (pictureBox1.Image != null)
{
using (var g = Graphics.FromImage(pictureBox1.Image))
{
g.SmoothingMode = SmoothingMode.HighQuality;
g.DrawLine(pen, mouseDownPosition, mouseMovePosition);
}
pictureBox2.Image = pictureBox1.Image;
}
}
isMoving = false;
}
private void pictureBox1_Paint(object sender, PaintEventArgs e)
{
if (isMoving)
{
if ((sender as PictureBox).Image == null) e.Graphics.Clear(Color.White);
e.Graphics.SmoothingMode = SmoothingMode.HighQuality;
e.Graphics.DrawLine(pen, mouseDownPosition, mouseMovePosition);
}
}
private void pictureBox2_Paint(object sender, PaintEventArgs e)
{
}
You have two problems here:
You paint on Control rather than an image. The image remains unchanged.
Both pictureBox1 and pictureBox2 refer to the same image. When you change the image, both controls will be affected on the next paint event.
So in pictureBox1_Paint you need create a copy of pictureBox1.Image (try using Bitmap), then paint on it and assign the updated image to pictureBox1.Image. It will be painted automatically.

Keep Picturebox Image While Painting on top of it

In my form, I have a picturebox. I wanted to be able to draw arrows on top of an image. I managed to get halfway there. On the Form load event, I assign an image to the picturebox. I'm able to create arrows with the code below. The problem is every time I create the arrow the picture I assigned on my form load event gets erased. Why does my image get erased? How do I maintain my image that I assigned on form load while drawing arrows on top of it?
private bool isMoving = false;
private Point mouseDownPosition = Point.Empty;
private Point mouseMovePosition = Point.Empty;
private List<Tuple<Point, Point>> lines = new List<Tuple<Point, Point>>();
Pen _Pen;
private void Test_Load(object sender, EventArgs e)
{
pictureBox1.Image = Properties.Resources.background;
}
private void pictureBox1_Paint(object sender, PaintEventArgs e)
{
if (isMoving)
{
if (pictureBox1.Image == null)
{
Bitmap bmp = new Bitmap(pictureBox1.Width, pictureBox1.Height);
using (Graphics g = Graphics.FromImage(bmp))
{
g.Clear(Color.White);
}
pictureBox1.Image = bmp;
}
using (Graphics g = Graphics.FromImage(pictureBox1.Image))
{
g.Clear(pictureBox1.BackColor);
AdjustableArrowCap bigArrow = new AdjustableArrowCap(5, 5);
_Pen = new Pen(Color.IndianRed, 3);
_Pen.CustomEndCap = bigArrow;
g.DrawLine(_Pen, mouseDownPosition, mouseMovePosition);
_Pen.Dispose();
}
}
}
private void pictureBox1_MouseDown(object sender, MouseEventArgs e)
{
isMoving = true;
mouseDownPosition = e.Location;
}
private void pictureBox1_MouseMove(object sender, MouseEventArgs e)
{
if (isMoving)
{
mouseMovePosition = e.Location;
pictureBox1.Invalidate();
}
}
private void pictureBox1_MouseUp(object sender, MouseEventArgs e)
{
if (isMoving)
{
lines.Add(Tuple.Create(mouseDownPosition, mouseMovePosition));
}
isMoving = false;
}
I think the problem is with this line here g.Clear(pictureBox1.BackColor);
Yes, problem is with this line here g.Clear(pictureBox1.BackColor); You erase entire the control area before you draw the line.
You should draw to e.Graphics directly:
private void pictureBox1_Paint(object sender, PaintEventArgs e)
{
if (isMoving)
{
if (pictureBox1.Image == null) e.Graphics.Clear(Color.White);
// Add this line for high quality drawing:
e.Graphics.SmoothingMode = SmoothingMode.HighQuality;
AdjustableArrowCap bigArrow = new AdjustableArrowCap(5, 5);
_Pen = new Pen(Color.IndianRed, 3);
_Pen.CustomEndCap = bigArrow;
e.Graphics.DrawLine(_Pen, mouseDownPosition, mouseMovePosition);
_Pen.Dispose();
}
}

How to select an area on a PictureBox.Image with mouse in C#

i just wanted to put a selection on my picturebox.image but this has just become worse than some little annoying situation. I thought on another picture box over the main picturebox but it seemed so lazy work to me. I need to know if there is a way to create a selection area (which is gonna be half transparent blue area) on a picturebox.image which im gonna draw with mouse and it shouldnt change the image im working on.
sample:
// Start Rectangle
//
private void pictureBox1_MouseDown(object sender, System.Windows.Forms.MouseEventArgs e)
{
// Determine the initial rectangle coordinates...
RectStartPoint = e.Location;
Invalidate();
}
// Draw Rectangle
//
private void pictureBox1_MouseMove(object sender, System.Windows.Forms.MouseEventArgs e)
{
if (e.Button != MouseButtons.Left)
return;
Point tempEndPoint = e.Location;
Rect =
new Rectangle(
Math.Min(RectStartPoint.X, tempEndPoint.X),
Math.Min(RectStartPoint.Y, tempEndPoint.Y),
Math.Abs(RectStartPoint.X - tempEndPoint.X),
Math.Abs(RectStartPoint.Y - tempEndPoint.Y));
Invalidate(Rect);
}
// Draw Area
//
private void pictureBox1_Paint(object sender, System.Windows.Forms.PaintEventArgs e)
{
// Draw the rectangle...
if (pictureBox1.Image != null)
{
Brush brush = new SolidBrush(Color.FromArgb(128, 72, 145, 220));
e.Graphics.FillRectangle(brush, Rect);
}
}
I used your code, you were nearly there. You needed to Invalidate the pictureBox1 instead of the rectangle. I also added a check for the Rect so it doesn't get drawn when it's not initialized or has no size.
Another important change: I created the Rectangle only once and I adjusted its location and size. Less garbage to clean up!
EDIT
I added a mouse right-click handler for the Rectangle.
private Point RectStartPoint;
private Rectangle Rect = new Rectangle();
private Brush selectionBrush = new SolidBrush(Color.FromArgb(128, 72, 145, 220));
// Start Rectangle
//
private void pictureBox1_MouseDown(object sender, System.Windows.Forms.MouseEventArgs e)
{
// Determine the initial rectangle coordinates...
RectStartPoint = e.Location;
Invalidate();
}
// Draw Rectangle
//
private void pictureBox1_MouseMove(object sender, System.Windows.Forms.MouseEventArgs e)
{
if (e.Button != MouseButtons.Left)
return;
Point tempEndPoint = e.Location;
Rect.Location = new Point(
Math.Min(RectStartPoint.X, tempEndPoint.X),
Math.Min(RectStartPoint.Y, tempEndPoint.Y));
Rect.Size = new Size(
Math.Abs(RectStartPoint.X - tempEndPoint.X),
Math.Abs(RectStartPoint.Y - tempEndPoint.Y));
pictureBox1.Invalidate();
}
// Draw Area
//
private void pictureBox1_Paint(object sender, System.Windows.Forms.PaintEventArgs e)
{
// Draw the rectangle...
if (pictureBox1.Image != null)
{
if (Rect != null && Rect.Width > 0 && Rect.Height > 0)
{
e.Graphics.FillRectangle(selectionBrush, Rect);
}
}
}
private void pictureBox1_MouseUp(object sender, MouseEventArgs e)
{
if (e.Button == MouseButtons.Right)
{
if (Rect.Contains(e.Location))
{
Debug.WriteLine("Right click");
}
}
}
private int xUp, yUp, xDown,yDown;
private Rectangle rectCropArea;
private void SrcPicBox_MouseUp(object sender, MouseEventArgs e)
{
//pictureBox1.Image.Clone();
xUp = e.X;
yUp = e.Y;
Rectangle rec = new Rectangle(xDown,yDown,Math.Abs(xUp xDown),Math.Abs(yUp-yDown));
using (Pen pen = new Pen(Color.YellowGreen, 3))
{
SrcPicBox.CreateGraphics().DrawRectangle(pen, rec);
}
rectCropArea = rec;
}
private void SrcPicBox_MouseDown(object sender, MouseEventArgs e)
{
SrcPicBox.Invalidate();
xDown = e.X;
yDown = e.Y;
}
private void btn_upload_Click(object sender, EventArgs e)
{
OpenFileDialog opf = new OpenFileDialog();
// PictureBox SrcPicBox = new PictureBox();
opf.Filter = "ALL images(*.*)|*.*";
if (opf.ShowDialog() == DialogResult.OK)
{
string name = opf.SafeFileName;
string filepath = opf.FileName;
File.Copy(filepath, name, true);
SrcPicBox.Image = Image.FromFile(opf.FileName);
}
private void btn_crop_Click(object sender, EventArgs e)
{
pictureBox3.Refresh();
//Prepare a new Bitmap on which the cropped image will be drawn
Bitmap sourceBitmap = new Bitmap(SrcPicBox.Image, SrcPicBox.Width, SrcPicBox.Height);
Graphics g = pictureBox3.CreateGraphics();
//Draw the image on the Graphics object with the new dimesions
g.DrawImage(sourceBitmap, new Rectangle(0, 0, pictureBox3.Width, pictureBox3.Height), rectCropArea, GraphicsUnit.Pixel);
sourceBitmap.Dispose();
}

erasing parts of the loaded image by mouse

I have loaded an image in my panel.I want to erase the parts of that image by using the mouse(dragging on the panel).Here is my code to load my image:
private void drawP_Paint(object sender, PaintEventArgs e)
{
e.Graphics.DrawImage(myImage, new Point(0, 0));
}
How can I do it?
Thanks in advance.
Updated:
sorry not to say earlier,I have set another image(image2) as background of the panel and I want it to be seen after erasing myImage(image loaded with the code above).
Hi I'm going to assume that you want this feature to work like the eraser on paint.
there are 3 events you are going to need
1.mousedown - to call the first erase and open up the mousemove event method.
2.mouseup - to stop the mousemove event method
3.mousemove - just to call the erase method
Code: //part pseudo as im not in visual studio right now :(
//global vars
bool enable = false;
void erase(Point mousepoint)
{
Point f = (mousepoint.X - yourpanel.left?, mousepoint.Y - yourpanel.top?);
//gets mouse position on accual picture;
yourImageGraphics.fillreactangle( f.X - 10, f.Y+10, 20,20 ,Color.White)
// int X , int Y, width , height, color
}
void mousedown(?)
{
enable=true;
erase(Cursor.Position //but you get this from e?);
}
void mouseup(?);
{
enable=false;
}
void mousemove(?)
{
if (enable)
erase(e.Position?);
}
Also it looks like you are going to have to make a graphics object for your panel :(
I hope this helps because question was a bit vague.
Here I created simple example. Of course it can be done better, but I just wondering how to do it... so sharing my results.
public partial class mainForm : Form
{
private Bitmap image;
private Rectangle imgRect;
public mainForm()
{
InitializeComponent();
BackColor = Color.Chartreuse;
image = new Bitmap(#"C:\image.jpg");
imgRect = new Rectangle(0,0,image.Width, image.Height);
}
private void main_Paint(object sender, PaintEventArgs e)
{
e.Graphics.DrawImage(image, 0, 0);
}
private void main_MouseMove(object sender, MouseEventArgs e)
{
if(e.Button == MouseButtons.Left && e.X < image.Width && e.Y < image.Height)
{
image.SetPixel(e.X, e.Y, Color.Magenta);//change pixel color;
image.MakeTransparent(Color.Magenta);//Make image transparent
Invalidate(imgRect);
}
}
}
...and lets test
Ha! scared that I deleted his eye :)
A TextureBrush on a pen can be used for erasing.
Working example (image1 and image2 are the same size images):
Bitmap bmp1;
TextureBrush tb;
Point _LastPoint;
public Form1()
{
InitializeComponent();
this.DoubleBuffered = true;
bmp1 = new Bitmap(#"c:\image1.png");
tb = new TextureBrush(new Bitmap(#"c:\image2.png"));
}
private void Form1_MouseMove(object sender, MouseEventArgs e) {
if (e.Button == MouseButtons.Left) {
if (!_LastPoint.IsEmpty) {
using (Graphics g = Graphics.FromImage(bmp1))
using (Pen p = new Pen(tb, 15)) {
p.StartCap = LineCap.Round;
p.EndCap = LineCap.Round;
g.DrawLine(p, _LastPoint, e.Location);
}
}
_LastPoint = e.Location;
this.Invalidate();
}
}
private void Form1_MouseUp(object sender, MouseEventArgs e) {
_LastPoint = Point.Empty;
}
private void Form1_Paint(object sender, PaintEventArgs e) {
e.Graphics.DrawImage(bmp1, new Point(0, 0));
}

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