I have a pictureBox1 with image inside and when i click on it its drawing points.
Now i added a reset button i called it when i click on it its should clear all the drawings i did on the pictureBox and leavethe image inside without the drawings on it.
I did:
private void button4_Click(object sender, EventArgs e)
{
Graphics graphics;
graphics = pictureBox1.CreateGraphics();
graphics.DrawImage(pictureBox1.Image, 0, 0);
}
So i draw a lot of points on pictureBox1 then click the button and all points are gone but then once i click on the picturebox1 again i see also the new points but also the old points i did before the clearing.
How can i clear the old drawings so it wont show up on the next clicks ?
This is the paint event: Moved the paint event to a new class:
public static void Paint(List<PointF> pb1points, GraphicsPath pb1gp, Point movingPoint, PictureBox pictureBox1, Graphics e)
{
e.Clear(Color.White);
e.DrawImage(pictureBox1.Image, movingPoint);
Pen p;
p = new Pen(Brushes.Green);
foreach (PointF pt in pb1points)
{
e.FillEllipse(Brushes.Red, pt.X, pt.Y, 3f, 3f);
}
using (Pen pp = new Pen(Color.Green, 2f))
{
pp.StartCap = pp.EndCap = LineCap.Round;
pp.LineJoin = LineJoin.Round;
e.DrawPath(pp, pb1gp);
}
}
You can try using Graphics.Clear().
Reference: http://msdn.microsoft.com/en-us/library/system.drawing.graphics.clear(v=vs.110).aspx
setting the Image property to null should work.
picBox.Image = null;
Ii it's not worked ,you might be used the InitialImage property to display your image.
pictBox.InitialImage = null;
Please refer the link:
Clear image on picturebox
This is working:
private void button4_Click(object sender, EventArgs e)
{
Graphics graphics;
graphics = pictureBox1.CreateGraphics();
graphics.DrawImage(pictureBox1.Image, 0, 0);
pb1points = new List<PointF>();
}
Related
I am trying to draw circles using Bitmap.
Each time I click the mouse, the circle I previously drew is moved to the new position.
What I want to happen is: Each time I click the mouse, a new circle is created/drawn at the position I clicked and all previously drawn circles remain without moving.
I am working with the following code:
using System;
using System.Drawing;
using System.Windows.Forms;
namespace multirectangle
{
public partial class Form1 : Form
{
public Form1()
{
InitializeComponent();
SetStyle(ControlStyles.OptimizedDoubleBuffer, true);
SetStyle(ControlStyles.AllPaintingInWmPaint, true);
}
Bitmap background;
Graphics scG;
Rectangle rectangleObj;
private Point clickCurrent = Point.Empty;
private Point clickPrev = Point.Empty;
private void Form1_Load(object sender, EventArgs e)
{
background = new Bitmap(Width, Height);
rectangleObj = new Rectangle(10, 10, 30, 30);
scG = Graphics.FromImage(background);
}
private void Form1_MouseDown(object sender, MouseEventArgs e)
{
clickCurrent = PointToClient(Cursor.Position);
clickPrev = clickCurrent;
if (clickPrev == Point.Empty) return;
rectangleObj.X = clickPrev.X - rectangleObj.Height / 2;// +radius;
rectangleObj.Y = clickPrev.Y - rectangleObj.Width / 2;
Refresh();
}
protected override void OnPaint(PaintEventArgs pe)
{
pe.Graphics.DrawImage(Draw(), 0, 0);
}
public Bitmap Draw()
{
Graphics scG = Graphics.FromImage(background);
Pen myPen = new Pen(System.Drawing.Color.Red, 3);
scG.Clear(SystemColors.Control);
scG.DrawEllipse(myPen, rectangleObj);
return background;
}
}
}
Your English was a little confusing. If I'm understanding your problem correctly, right now the only thing that's being drawn is the new circle where the click was, and you want all the old ones to persist as well? In which case, there are two options:
Don't clear the bitmap before you draw. scG.Clear(SystemColors.Control); will clear the bitmap you just drew. If you remove that line and don't clear the bitmap, then the next time you click, it will then draw the new ellipse right on top of the last bitmap.
If you want a fresh drawing/bitmap everytime, you would need a list of your rectangleObj . Each time you click, you add that point to your rectangleObj collection. Then in your draw method, you would iterate through the collection and draw all of them.
I notice a few things. First, in Form1_MouseDown(), you have this:
clickCurrent = PointToClient(Cursor.Position);
clickPrev = clickCurrent;
You are overwriting the old position (clickPrev) before you even save it. If you want to keep both positions, you should put them in a simple structure, like a List. When you get a new point, just Add() it to the list. Then, in your Draw() routine, loop over all the elements in the list and draw them all.
If you just want two positions--and only two--just swap your statements like this:
clickPrev = clickCurrent;
clickCurrent = PointToClient(Cursor.Position);
And you'll have to allocate another rectangle object for the drawing, although it would make more sense to take care of this in the Draw() routine.
Swap the position of the following statements
clickCurrent = PointToClient(Cursor.Position);
clickPrev = clickCurrent;
I think you are assigning the clickCurrent to clickPrevious after you initialize clickCurrent. It needs to be the other way.
Please try this
Rectangle rectangleObj;
Bitmap background;
Graphics scG;
Pen myPen;
private void Form1_Load(object sender, EventArgs e)
{
rectangleObj = new Rectangle(10, 10, 30, 30);
background = new Bitmap(Width, Height);
scG = Graphics.FromImage(background);
myPen = new Pen(Color.Red, 3);
BackgroundImage = background;
}
private void Form1_MouseDown(object sender, MouseEventArgs e)
{
var point = PointToClient(Cursor.Position);
rectangleObj.X = point.X - rectangleObj.Height / 2;
rectangleObj.Y = point.Y - rectangleObj.Width / 2;
scG.DrawEllipse(myPen, rectangleObj);
Refresh();
}
OnPaint and Draw methods removed. As well as clickCurrent and clickPrev fields.
When you change the form size (for example, maximize it), Bitmap and Graphics remain the same, so you get this effect. To avoid this, you need to add the event handler
private void Form1_SizeChanged(object sender, EventArgs e)
{
background = new Bitmap(Width, Height);
scG = Graphics.FromImage(background);
BackgroundImage = background;
}
Note that each time you resize the form, all previously drawn is erased. If this is undesirable, a different approach is needed for drawing. Let me know, I will give another example.
How to draw image on tabPage overlapping buttons
Black circles(DrawImage on tabPage8_Paint) should be above the buttons:
http://rghost.ru/6sVBl8mkh/image.png
It must be so:
http://rghost.ru/6BgDM77pq/image.png
My code
public SibModem() {
InitializeComponent();
tabPage8.Paint += new PaintEventHandler(tabPage8_Paint);
gettime();
this.SizeChanged += new EventHandler(this.SibModem_Resize);
}
protected void tabPage8_Paint(object sender, PaintEventArgs e) {
GraphicsUnit units = GraphicsUnit.Pixel;
base.OnPaint(e);
Graphics g = e.Graphics;
g.DrawImage(bg, 0, 0);
Rectangle srcRect = new Rectangle(offsetant, 0, w, h);
g.DrawImage(anten, x, y, srcRect, units);
Rectangle ussdwaitRect = new Rectangle(offsetussd, 0, 64, 64);
g.DrawImage(ussdwait, usx, usy, ussdwaitRect, units);
}
You can't draw above nested controls, so you need to draw parts of the image onto those Buttons.
So combine drawing onto the tabpage and drawing onto the buttons you need to adorn!
Here is a simple example using only one image:
A few class level variables:
Point iLoc = Point.Empty;
Image img = null;
List<Button> overlaidButtons = new List<Button>();
Prepare the image, its position and a list of possibly overlaid buttons:
public Form1()
{
InitializeComponent();
string imgN = #"d:\scrape\gears\gear_12x4hand.png";
img = Image.FromFile(imgN);
iLoc = new Point(100, 100);
overlaidButtons.AddRange(new []{button10,button11,button12,button13 });
// each button calls the same paint event
foreach (Button btn in overlaidButtons) btn.Paint += btn_Paint;
}
The common Paint event. We calculate the relative position of the image..
void btn_Paint(object sender, PaintEventArgs e)
{
Button btn = sender as Button;
e.Graphics.DrawImage(img, new Point(iLoc.X - btn.Left, iLoc.Y - btn.Top));
}
Note that if the Buttons are nested deeper you need to adapt the calculation to include all levels of nesting!
The TabPage Paint event:
private void tabPage5_Paint(object sender, PaintEventArgs e)
{
e.Graphics.DrawImage(img, iLoc);
}
Try BringToFront method, it brings the control to the front of the z-order.
See this reference on MSDN: https://msdn.microsoft.com/en-us/library/system.windows.forms.control.bringtofront(v=vs.110).aspx
I have a small app that looks pretty much like old Paint from Windows. I implemented all the Graphic using picture box Paint event. The only problem is that when I click this button a Color Dialog box should appear and let me change the color of my pen. But whenever I click the button the box never appears and my program gets stuck in the Paint event, most precisely at the line where I do the following:
pictureBox1.Image = bmp;
What I am doing wrong? Please, I would appreciate any help!
I hope the following code snippet is enough.
This is my picturebox Paint event:
private void pictureBox1_Paint(object sender, PaintEventArgs e)
{
using(Graphics g = Graphics.FromImage(bmp))
{
if (lineButton && mouseIsUp)
{
g.DrawLine(myPen, mAnchorPoint, mFinalPoint);
mAnchorPoint = Point.Empty;
mFinalPoint = Point.Empty;
}
pictureBox1.Image = bmp;
}
}
And this is the button event that fires up when I wish to change my pen color:
private void ColorButton_Click(object sender, EventArgs e)
{
ColorDialog cd = new ColorDialog();
if (cd.ShowDialog() == DialogResult.OK)
{
myPen.Color = cd.Color;
}
}
Don't use pictureBox1.Image = bmp; inside pictureBox1_Paint. Instead:
private void pictureBox1_Paint(object sender, PaintEventArgs e)
{
using(Graphics g = Graphics.FromImage(bmp))
{
if (lineButton && mouseIsUp)
{
g.DrawLine(myPen, mAnchorPoint, mFinalPoint);
mAnchorPoint = Point.Empty;
mFinalPoint = Point.Empty;
}
//pictureBox1.Image = bmp;
}
e.Graphics.DrawImage(bmp, 0, 0);
}
Or, a better approach, set pictureBox1.Image = bmp; once, do all your drawings on bmp(not in pictureBox1_Paint) and final call pictureBox1.Invalidate();. You don't need to write code in pictureBox1_Paint().
I'm working on a winforms project that involves cropping an image. My goal is to do this by using a fixed-size draggable picturebox control, allowing the user to select the area they want to preserve.
My problem is when I crop the image; it "works", but the crop area offsets a little. Here's the result I get:
To clarify, I'm not talking about the zooming, that's per design. Notice the orange box is mostly focusing on the eye of the storm, but the cropped image is not.
This is my code for the crop operation:
private void tsbRecortar_Click(object sender, EventArgs e)
{
Rectangle recorte = new Rectangle(pbxSeleccion.Location.X, pbxSeleccion.Location.Y, pbxSeleccion.Width, pbxSeleccion.Height);
foto = recortarImagen(foto, recorte);
pbxImagen.Image = foto;
}
private Image recortarImagen(Image imagen, Rectangle recuadro)
{
try
{
Bitmap bitmap = new Bitmap(imagen);
Bitmap cropedBitmap = bitmap.Clone(recuadro, bitmap.PixelFormat);
return (Image)(cropedBitmap);
}
catch (Exception ex)
{
MessageBox.Show(ex.Message, "Error");
return null;
}
}
pbxSeleccion is the draggable orange rectangle; its parent is pbxImage (I re-parent it on form's load).
As you can see, I'm using the coordinates of pbxSeleccion to define the starting point of the crop area, but is not working as expected... sometimes, I even get an "Out of Memory" exception.
I think this has to do with how the image loads in the parent picturebox, something about how the margin is handled "under the hood", but nothing I tried fixes it... just changes the magnitude of the offset.
Searching the web and SO has helped me a lot, but for this particular issue, I can't seem to find an answer... please, feel free to point out improvements to my code, I haven't been coding for long and I'm new to C# and .NET
Any help is highly appreciated. Cheers!
Suppose your original image is displayed in a PictureBox. You passed in the wrong location of the orange cropping window. Here is the corrected code for you:
private void tsbRecortar_Click(object sender, EventArgs e){
Point p = yourPictureBox.PointToClient(pbxSelection.PointToScreen(Point.Empty));
Rectangle recorte = new Rectangle(p.X, p.Y, pbxSeleccion.Width, pbxSeleccion.Height);
foto = recortarImagen(foto, recorte);
pbxImagen.Image = foto;
}
I use PointToClient and PointToScreen here because I think it's the best way to do. You can then change the container of your pictureBox safely without having to modify the code. If you use the code like the following, it's not dynamically enough when you want to place your pictureBox in another container:
Rectangle recorte = new Rectangle(pbxSeleccion.X + yourPictureBox.Left,
pbxSeleccion.Y + yourPictureBox.Top,
pbxSeleccion.Width, pbxSeleccion.Height);
NOTE: you can also use RectangleToClient and RectangleToScreen like this:
private void tsbRecortar_Click(object sender, EventArgs e){
Rectangle recorte = yourPictureBox.RectangleToClient(pbxSeleccion.RectangleToScreen(pbxSeleccion.ClientRectangle));
foto = recortarImagen(foto, recorte);
pbxImagen.Image = foto;
}
Try This Code for Cropping the Image in picturebox
public static Image Fit2PictureBox(this Image image, PictureBox picBox)
{
Bitmap bmp = null;
Graphics g;
// Scale:
double scaleY = (double)image.Width / picBox.Width;
double scaleX = (double)image.Height / picBox.Height;
double scale = scaleY < scaleX ? scaleX : scaleY;
// Create new bitmap:
bmp = new Bitmap(
(int)((double)image.Width / scale),
(int)((double)image.Height / scale));
// Set resolution of the new image:
bmp.SetResolution(
image.HorizontalResolution,
image.VerticalResolution);
// Create graphics:
g = Graphics.FromImage(bmp);
// Set interpolation mode:
g.InterpolationMode = InterpolationMode.HighQualityBicubic;
// Draw the new image:
g.DrawImage(
image,
new Rectangle( // Ziel
0, 0,
bmp.Width, bmp.Height),
new Rectangle( // Quelle
0, 0,
image.Width, image.Height),
GraphicsUnit.Pixel);
// Release the resources of the graphics:
g.Dispose();
// Release the resources of the origin image:
image.Dispose();
return bmp;
}
public static Image Crop(this Image image, Rectangle selection)
{
Bitmap bmp = image as Bitmap;
// Check if it is a bitmap:
if (bmp == null)
throw new ArgumentException("Kein gültiges Bild (Bitmap)");
// Crop the image:
Bitmap cropBmp = bmp.Clone(selection, bmp.PixelFormat);
// Release the resources:
image.Dispose();
return cropBmp;
}
Write The Following Code For Mouse Event on PictureBox
private void pictureBox1_MouseDown(object sender, MouseEventArgs e)
{
if (e.Button == MouseButtons.Left)
{
_selecting = true;
_selection = new Rectangle(new Point(e.X, e.Y), new Size());
}
}
private void pictureBox1_MouseUp(object sender, MouseEventArgs e)
{
if (e.Button == MouseButtons.Left && _selecting)
{
// Create cropped image:
try
{
Image img = pictureBox1.Image.Crop(_selection);
// Fit image to the picturebox:
pictureBox1.Image = img.Fit2PictureBox(pictureBox1);
}
catch { }
_selecting = false;
}
}
private void pictureBox1_MouseMove(object sender, MouseEventArgs e)
{
// Update the actual size of the selection:
if (_selecting)
{
_selection.Width = e.X - _selection.X;
_selection.Height = e.Y - _selection.Y;
// Redraw the picturebox:
pictureBox1.Refresh();
}
}
private void pictureBox1_Paint(object sender, PaintEventArgs e)
{
if (_selecting)
{
// Draw a rectangle displaying the current selection
Pen pen = Pens.LightSkyBlue;
e.Graphics.DrawRectangle(pen, _selection);
}
}
Output Screen
Before Cropping
After Cropping
I have a Panel called panel1 and I am trying to draw a line on my panel1 using this code:
var g = panel1.CreateGraphics();
var p = new Pen(Color.Black, 3);
var point1 = new Point(234,118);
var point2 = new Point(293,228);
g.DrawLine(p, point1, point2);
But nothing is showing up. Any ideas? This is in a windows form.
Handle the Panel's Paint event and put it in there. What's happening is that it's being drawn once in the constructor but then being drawn over in the Paint event everytime it's called.
private void panel1_Paint(object sender, PaintEventArgs e)
{
base.OnPaint(e);
using(Graphics g = e.Graphics)
{
var p = new Pen(Color.Black, 3);
var point1 = new Point(234,118);
var point2 = new Point(293,228);
g.DrawLine(p, point1, point2);
}
}
Put it in some event after the form has been created and shown on the screen and it should work fine.
It's best to put it in the Paint event, as keyboardP stated, but it will not show up if called before the form is shown on the screen.
To test this you can add a button and add the code to the click event:
private void button1_Click(object sender, EventArgs e)
{
using (Graphics g = panel1.CreateGraphics())
{
g.DrawLine(new Pen(Color.Back, 3), new Point(234,118), new Point(293,228));
}
}
To see your drawing - you can simply make a button with a Click Event and draw when the button is clicked. For example:
private void btnDraw_Click(object sender, EventArgs e)
{
Graphics dc = drawingArea.CreateGraphics();
Pen BlackPen = new Pen(Color.Black, 2);
dc.DrawLine(BlackPen, 0, 0, 200, 200);
BlackPen.Dispose();
dc.Dispose();
}
Oh, and by the way "drawingArea" is the (Name) of either a PictureBox or Panel you have added to your form (to draw in it).
If you follow the other answers and still your drawings are not showing up try removing all controls from the control that is being drawn to. The other controls may be covering whatever you are trying to draw.
private void button2_Click(object sender, EventArgs e)
{
panel1.Paint += new PaintEventHandler(
(object sender1, PaintEventArgs e1) => {
var p = new Pen(Color.Black, 3);
var point1 = new Point(234, 118);
var point2 = new Point(293, 228);
e1.Graphics.DrawLine(p, point1, point2);
}
);
panel1.Invalidate();
}