I have created a PictureBox in a panel. I drew some graphics on PictureBox.
I want to get those graphics on button clicking. How can I do that?
Check this link. In particular the 46.9 How do I programmatically load, modify and save a bitmap? section of that page.
You'll get the idea even though the code sample is in VB.
Good luck!
I think what you want is You have some graphics drawn over a PictureBox and you want a Image of those graphics on the click of a Button,isn't it.I am not sure if this'll work but try it;
private void ButtonGetImage_Click(object sender, EventArgs e)
{
if (SourcePictureBox.Image != null)//Just to make sure it's not empty.
{
Bitmap graphic = new Bitmap(SourcePictureBox.Image);
{
//Add some logic to modify Image if you want.
graphic.Save(#"F:\Image.bmp");//An appropriate path to save the file.
graphic.Dispose();
}
}
}
Related
I know there are many questions on this, but I just can't get it to work. I have this event:
private void pictureBox1_Paint(object sender, System.Windows.Forms.PaintEventArgs e)
{
e.Graphics.DrawRectangle(new Pen(selectionBrush, 1), selectionRectangle);
}
It works as it should. Draws a colored rectangle over the image I put inside picture box. But after I draw that rectangle, I want to erase it. I basically use it as selection area for cropping the image. Is there a way that I can erase the rectangle that I have drawn? Thanks.
Here is where I want to erase the rectangle:
private void button1_Click(object sender, EventArgs e)
{
//here are some examples of what I have tried
pictureBox1.Invalidate();
Invalidate();
}
Your Paint routine has a call to DrawRectangle. Then you invalidate the rectangle. At that point, your paint routine will get called again, and, if your code to draw the rectangle is still there, it will get redrawn. You need to make it so the DrawRectangle call no longer gets called once you don't need it any more (with an if statement or something).
You also probably want to inflate the size of the invalidation rectangle by one pixel all around to make sure you don't leave any bread crumbs behind
I want to make a graph paper grid and set the drawing to the image of a picture box. Now I might even be using the wrong thing for drawing a graph paper grid but I have asked around and some people said that the DrawGrid method would work. None of the code below is returning any errors, but when I run the button1_Click method, it doesn't display anything to the picturebox.
private void button1_Click(object sender, EventArgs e)
{
button2.Visible = true;
Bitmap bmp = new Bitmap(pictureBox1.ClientSize.Width, pictureBox1.ClientSize.Height);
Size yourGridspacing = new Size((int)numericUpDown1.Value, (int)numericUpDown2.Value);
using (Graphics G = Graphics.FromImage(bmp))
{
ControlPaint.DrawGrid(G, new Rectangle(Point.Empty, bmp.Size), yourGridspacing , Color.Black);
}
pictureBox1.Image = bmp;
}
Any idea what the problem might be?
Your PictureBox probably has a White Background.. If so, please tell the ControlPaint.DrawGrid method so..:
ControlPaint.DrawGrid(G, new Rectangle(Point.Empty, bmp.Size),
yourGridspacing , Color.White);
The param doesn't control the color of the dots; it is supposed to help find a Color that will contrast. So maybe the best way to write it will be:
ControlPaint.DrawGrid(G, new Rectangle(Point.Empty, bmp.Size),
yourGridspacing, pictureBox1.BackColor);
This will work for all colors except Color.Transparent.. (in which case the Color of the control below will decide if the dots are visible..)
You may wonder, why such a roundabout way is chosen? Well, the method DrawGrid is not really meant as a normal drawing method, like the ones in Graphics. It is one of several methods that are meant to construct a robust display of Windows controls like Button or CheckBox.. Now, the Background over which the Grid is drawn need not have only one Color; it could be an Image or a Gradient and it could change..
You are supposed to pick a typical color to represent that background. The system will then choose a Color with good contrast for the dots.
For a way to control the grid's color see the last option in my other answer!
I would like to be able to fill any given area of an image with a given color, much like you can use paint to fill a rectangle, circle or any other shape delimited by a color.
To make this simpler I already have made the picture box source image to have the same size as the picture box itself, which should make things a bit easier.
How can I do this given that I have a picture box with an image and an already defined color and the user only has to click over the picture box to fill in any area with such color.
void pictureBox1_MouseClick(object sender, MouseEventArgs e)
{
// The color to be used
Color color = Color.Red;
// Image has same dimensions as picturebox to make things easier
Image img = pictureBox1.Image;
// Where it was clicked.
Point clickCoords = new Point(e.X, e.Y);
// Coloring that area clicked much like Paint does. How?
...
// After coloring show the result in the picture box again
pictureBox1.Image = img;
}
Thanks.
EDIT: Example of my desired behavior.
To make my goal obvious, let me add this small example.
You know MS Paint right?
You selected the pencil tool and start doing anything on the canvas, doesn't matter form or shape or even if the points your are doing with the pencil are connected or not.
Now you select the bucket tool and start clicking on the canvas. What will it do? Fill in the selected area according to the color you clicked over and how far she goes without changing with the color you have selected on the color pallet.
This is the behavior I want to emulate on my picture box mouse click event.
What you are looking for is a flood-fill algorithm. This should do the trick just fine.
The algorithm recursively searched for neighboring uncolored pixels, until it hits a wall.
You can use the code from here:
// Load the image (probably from your stream)
Image image = Image.FromFile( imagePath );
using (Graphics g = Graphics.FromImage(image))
{
Color customColor = Color.FromArgb(50, Color.Gray);
SolidBrush shadowBrush = new SolidBrush(customColor);
g.FillRectangles(shadowBrush, new RectangleF[] { rectFToFill });
}
image.Save( imageNewPath );
, but there is a one thing you missed - a rectFToFill, which you should define according your click event. There are a lot of strategies you can use, I suggest you to handle a Drag event or something like that, save the event start point and end point, after that define the rectangular you must fill:
You should examine the event points and after that create the Rectangle(F) structure using some of its constructors.
The Graphics class has a dozen methods you can use to draw some shapes or lines on your Image.
I am building a C# app that shows the trajectory of a cannonball. But when I minimize it the trajectory I have drawn to a picture box are gone when I bring it back up. Is there an easy way to stop this?
I bet your drawing in the mouse event. Use the onpaint event and you should be good to go.
Edit:
Here is a decent drawing tutorial using the onpaint() event:
http://www.geekpedia.com/tutorial50_Drawing-with-Csharp.html
When the window is restored it will need to redraw the form. If you do not have your drawing as part of the paint event, then it will not be redrawn.
This question is very similar to this one
Saving a Graphics content to a file
As the others have already stated the problem is when you draw onto a graphics object, there is nothing retained. It is called persistent graphics. Sometimes you want this behavior, more often than not you don't.
You should do your drawing onto a bitmap, then copy the bitmap to your picturebox.Image. The other option as stated in the other answers, is do your drawing routines in the OnPaint Method.
Read my answer in the above. The title is misleading, he thought he had to save to a file to gain persistence, but we showed him otherwise.
EDIT Here is the important code from the above link
Bitmap buffer;
public Form1()
{
InitializeComponent();
panel1.BorderStyle = BorderStyle.FixedSingle;
buffer = new Bitmap(panel1.Width,panel1.Height);
//Make sure you resize your buffer whenever the panel1 resizes.
}
private void button1_Click(object sender, EventArgs e)
{
using (Graphics g = Graphics.FromImage(buffer))
{
g.DrawRectangle(Pens.Red, 100, 100,100,100);
}
panel1.BackgroundImage = buffer;
}
i was having same problem just used mainp.refresh() after event change
mainp was my panel in which i was drawing my all graphics
I am trying to create this simple application in c#: when the user double clicks on specific location in the form, a little circle will be drawn. By one click, if the current location is marked by a circle - the circle will be removed.
I am trying to do this by simply register the MouseDoubleClick and MouseClick events, and to draw the circle from a .bmp file the following way:
private void MouseDoubleClick (object sender, MouseEventArgs e)
{
Graphics g = this.CreateGraphics();
Bitmap myImage = (Bitmap)Bitmap.FromFile("Circle.bmp");
g.DrawImage(myImage, e.X, e.Y);
}
My problem is that I dont know how to make the circle unvisible when the user clicks its location: I know how to check if the selected location contains a circle (by managing a list of all the locations containig circles...), but I dont know how exactly to delete it.
Another question: should I call the method this.CreateGraphics() everytime the user double-clicks a location, as I wrote in my code snippet, or should I call it once on initialization?
My personal preference is to put my images in instances of the Picturebox class. Reason being, I can simply call each Picturebox's Hide() function (or set 'Visible` to false).
What you're doing is drawing directly onto the window's client area, which technically isn't wrong but normally should be done in the form's Paint handler. If at some point you decide you don't want your circle to be visible anymore, you can call the form's Invalidate() method which triggers the Paint event. There, you explicitly do not draw your circle, and so to the user, the circle disappears.
The nice thing about a Picturebox is that it's persistent - you put your image into it and optionally draw on that image, but you only need to draw once. If you use the Paint handler technique, your drawing code gets called each time the form needs to redraw itself.
Edit:
Here's some code that illustrates my Paint handler information:
private void Form_Paint(object sender, PaintEventArgs e)
{
e.Graphics.Clear(); // clear any and all circles being drawn
if (CircleIsVisible)
{
e.Graphics.DrawEllipse( ... ); // OR, DrawImage( ) as in your example
}
}
private void MouseDoubleClick (object sender, MouseEventArgs e)
{
CircleIsVisible = true;
Invalidate(); // triggers Paint event
}
If you're drawing bitmaps, I would load the bitmap once and store it as a class variable. This way you don't need to hit the hard drive each time you want to draw. Dispose of the bitmap when you dispose of your class (in this case, your window).
I thinks you should clear all of the image you draw before your next double click.
Such as Graphics.Clear().
On the other hand, you should not to create Graphics object or dispose it every time.
If you have simple background color you could use Graphics.DrawEllipse to draw Circles and then just change circle color to the background color. Also you need to have a Collection of all circles you draw so you can access any circle that you've drawn.