Trying to draw a shape over existing panels for a good while, but by now out of ideas. Could somebody help me out, please? It ends up always behind the panels (and pictureBox /the grey one/). I tried 3 different ways, whithout success. this is my code:
namespace DrawingOnFront
{
public partial class Form1 : Form
{
public Form1()
{
InitializeComponent();
}
private void panel11_MouseClick(object sender, MouseEventArgs e)
{
DrawIt(90, 70);
}
private void DrawIt(int x, int y)
{
Rectangle Circle = new Rectangle(x,y,40,40);
SolidBrush Red = new SolidBrush(Color.Red);
Graphics g = this.CreateGraphics();
g.FillEllipse(Red, Circle);
/*
Bitmap bmp = new Bitmap(pictureBox1.Width, pictureBox1.Height);
Graphics g = Graphics.FromImage(bmp);
int width = pictureBox1.Width /4;
int height = pictureBox1.Height /2;
int diameter = Math.Min(width, height);
g.FillEllipse(Red, x, y, width, height);
pictureBox1.Image = bmp;
*/
}
protected override void OnPaint(PaintEventArgs e)
{
base.OnPaint(e);
using (Graphics g = e.Graphics)
{
Rectangle Circle = ClientRectangle;
Circle.Location = new Point(100, 60);
Circle.Size = new Size(40, 40);
using (SolidBrush Green = new SolidBrush(Color.Green))
{
g.FillEllipse(Green, Circle);
}
}
}
}
}
Sorry for this basic lama question, probably for most of you it is very easy, I am still learning it. Thanks a lot in advance.
My comments above apply. Here is an example of how to draw onto each control and the form separately:
We best have a common drawing routine that we can call from the Paint event of each participating element, in our case a Panel, a PictureBox and the Form.
The trick is for all nested elements to draw the circle shifted by their own location. To do so we pass these things into the drawing routine:
a valid Graphics object. We get it from the Paint events.
and a reference to the control; we use it to offset the drawing on each control (except the form) with Graphics.TranslateTransform..:
Result:
As you can see it looks as if we painted one circle over all elements but actually we drew three circles, each onto one element..:
private void canvasForm_Paint(object sender, PaintEventArgs e)
{
draw(sender as Control, e.Graphics);
}
private void panel1_Paint(object sender, PaintEventArgs e)
{
draw(sender as Control, e.Graphics);
}
private void pictureBox1_Paint(object sender, PaintEventArgs e)
{
draw(sender as Control, e.Graphics);
}
private void draw(Control ctl, Graphics g)
{
Rectangle r = new Rectangle(200, 100, 75, 75);
if (ctl != canvasForm) g.TranslateTransform(-ctl.Left, -ctl.Top);
g.FillEllipse(Brushes.Green, r);
g.ResetTransform();
}
Note that the same result could be created with three calls, one FillRectangle, one DrawImage and one FillEllipse :-)
Related
I am creating a Graphics Form where objects with coordinates x,y are being drawn into the Graphics. It works properly for small x and y, but when I want to draw them in different place (f.e. x = 500, y = 300) they disappear.
public WindowHandler()
{
dc = this.CreateGraphics();
this.Size = new Size(sizeX, sizeY); // 800x600
startSimulation = new Button
{
// button properties
};
this.Controls.Add(startSimulation);
startSimulation.Click += new EventHandler(StartSimulationClick);
}
private void CreationsMethods()
{
creations.PaintAllAnimals(dc);
}
public void PaintAllAnimals(Graphics g)
{
foreach (var animal in ecoStructure.world.animals)
{
animal.PaintAnimal(g);
}
}
public void PaintAnimal(Graphics graphics)
{
Rectangle rectangle = new Rectangle(x, y, 3, 3);
Pen pen = new Pen(colour);
graphics.DrawRectangle(pen, rectangle);
graphics.FillRectangle(colour, rectangle);
}
I want to put all the objects onto the window. Is there any way to make the Graphics "bigger"? Do I need to make another one? Or should I use different tool to draw rectangles?
Thanks to #Chris Dunaway for posting an answer in comment.
So I deleted the CreateCraphics, and instead of that i am now using an OnPaint method. It works slowly, but works. So I will try to make it as fast as i can. For now, I just created this. NextStepClick is how I use the OnPaint to paint the rectangles.
private void CreationsMethods(object sender, PaintEventArgs e)
{
dc = e.Graphics;
base.OnPaint(e);
creations.PaintAllAnimals(dc);
}
private void NextStepClick(object sender, EventArgs e)
{
this.Refresh();
picBox.Paint += new System.Windows.Forms.PaintEventHandler(CreationsMethods);
}
I made an user control and I draw a rectangle directly in the window, like this (this is a simplified version):
private int rec_len = 200;
private void Draw_()
{
Pen pn = new Pen( Color.Black, WIDTH_LINE );
Graphics graph = this.CreateGraphics();
graph.Clear( Color.Transparent );
this.Refresh();
graph.DrawRectangle( pn, 20, 10, rec_len, 40 );
this.Refresh();
graph.Dispose();
}
public void button_Build_Click( object sender, EventArgs e )
{ rec_len += 10; Draw_(); }
The strange thing is that the second refresh actually poses a problem: if I comment it out, the rectangle is visible, if I let it in the code, the rectangle is not visible. In the real code I have to draw more than a rectangle and I want the refresh at the end, otherwise the background is visible between the moment I erase old drawing and the moment the new one is ready.
The surface of a control is not stored: When you paint on a control, the drawing is not saved and need to be redrawn each time the control is repainted (After a refresh for example). To create a persistante graphic, you can create a bitmap, draw on the bitmap and assign this bitmap to the BackgroundImage property.
Bitmap bmp = new Bitmap(WIDTH, HEIGHT);
void Initialize()
{
this.BackgroundImage = bmp;
}
private int rec_len = 200;
private void Draw_()
{
Pen pn = new Pen(Color.Black, WIDTH_LINE);
using (Graphics graph = Graphics.FromImage(bmp))
{
graph.Clear(Color.Transparent);
this.Refresh();
graph.DrawRectangle(pn, 20, 10, rec_len, 40);
this.Refresh();
}
}
public void button_Build_Click(object sender, EventArgs e) { rec_len += 10; Draw_(); }
I am adding one panel to another panel it works but circle which is in inspanel not shown. how can i solved this.
I am using below code. It works but not show circle
public static int xTemp = 0;
public static int yTemp = 0;
private void button1_Click(object sender, EventArgs e)
{
Panel insPanel = new Panel();
Random xRandom = new Random();
xTemp= xRandom.Next(20,100);
Random yRandom = new Random();
yTemp = yRandom.Next(20, 100);
insPanel.Location = new Point(xTemp, yTemp);
insPanel.Width=40;
insPanel.Height = 40;
insPanel.Visible = true;
insPanel.BorderStyle = BorderStyle.FixedSingle;
insPanel.Paint += new PaintEventHandler(insPanel_Paint);
panel1.Controls.Add(insPanel);
}
void insPanel_Paint(object sender, PaintEventArgs e)
{
System.Drawing.SolidBrush myBrush = new System.Drawing.SolidBrush(System.Drawing.Color.Red);
System.Drawing.Graphics formGraphics =this.CreateGraphics();
formGraphics.FillEllipse(myBrush, new Rectangle(xTemp,yTemp, 10, 10));
myBrush.Dispose();
formGraphics.Dispose();
}
Main issue: you're trying to draw your circle at wrong coordinates.
xTemp and yTemp are coordinates of insPanel relative to panel1. But when you drawing your circle, you should use coordinates relative to panel you're drawing at - insPanel.
Another issue: there is no need to create and dispose graphics each time you're drawing something on your panel. You can use e.Graphics from Paint eventhandler arguments.
Based on above, your code could look like:
void insPanel_Paint(object sender, PaintEventArgs e)
{
using (var myBrush = new SolidBrush(Color.Red))
{
e.Graphics.FillEllipse(myBrush, new Rectangle(0, 0, 10, 10));
}
}
Also note - since paint event can occur very frequently, it could be a good idea not to create and dispose brush every time, but use brush cached in your class private field.
Use e.Graphics instead of this.CreateGraphics:
System.Drawing.Graphics formGraphics = e.Graphics;
One more issue is you're getting coordinates in range of 20 - 100 (xRandom.Next(20,100)) and your panel dimensions are just 40, 40.
Im trying to draw a graphic on a form upon form startup. I've tried putting the graphic components inside the form constructer, but i cannot seem to get it working. This is what i've got so far.
public partial class Form3 : Form
{
public Form3()
{
System.Drawing.Graphics graphics = this.CreateGraphics();
System.Drawing.Rectangle rectangle = new System.Drawing.Rectangle(100, 100, 200, 200);
graphics.DrawEllipse(System.Drawing.Pens.Black, rectangle);
graphics.DrawRectangle(System.Drawing.Pens.Red, rectangle);
}
}
Any and all help will be awesome,
Thanks guys
One solution would be to use a Bitmap, e.g.
Bitmap b = new Bitmap(this.Width, this.Height);
Graphics g = Graphics.FromImage(b);
... // Draw
this.BackgroundImage = b;
Otherwise, you'll need to handle the Paint event, whereat you can draw directly to the graphics context each time the form is invalidated. e.g.
this.Paint += Form1_Paint;
...
private void Form1_Paint(object sender, PaintEventArgs e)
{
Graphics g = e.Graphics;
System.Drawing.Rectangle rectangle = new System.Drawing.Rectangle(100, 100, 200, 200);
g.DrawEllipse(System.Drawing.Pens.Black, rectangle);
g.DrawRectangle(System.Drawing.Pens.Red, rectangle);
}
private void Form1_Paint(object sender, PaintEventArgs e)
{
System.Drawing.Rectangle rectangle = new System.Drawing.Rectangle(100, 100, 200, 200);
e.Graphics.DrawEllipse(System.Drawing.Pens.Black, rectangle);
e.Graphics.DrawRectangle(System.Drawing.Pens.Red, rectangle);
}
I have created a small application in C#, in which I draw a rectangle when the mouse is moved.
However, when the form is minimized or maximized, the drawing is erased. Also, when I draw a second time, the drawing of the first rectangle is erased.
How can I solve this problem? Here is the code that I currently have:
int X, Y;
Graphics G;
Rectangle Rec;
int UpX, UpY, DwX, DwY;
public Form1()
{
InitializeComponent();
//G = panel1.CreateGraphics();
//Rec = new Rectangle(X, Y, panel1.Width, panel1.Height);
}
private void pictureBox1_MouseDown(object sender, MouseEventArgs e)
{
UpX = e.X;
UpY = e.Y;
//Rec = new Rectangle(e.X, e.Y, 0, 0);
//this.Invalidate();
}
private void pictureBox1_MouseUp(object sender, MouseEventArgs e)
{
DwX = e.X;
DwY = e.Y;
Rec = new Rectangle(UpX, UpY, DwX - UpX, DwY - UpY);
Graphics G = pictureBox1.CreateGraphics();
using (Pen pen = new Pen(Color.Red, 2))
{
G.DrawRectangle(pen, Rec);
}
}
private void pictureBox1_MouseMove(object sender, MouseEventArgs e)
{
if (e.Button == MouseButtons.Left)
{
// Draws the rectangle as the mouse moves
Rec = new Rectangle(UpX, UpY, e.X - UpX, e.Y - UpY);
Graphics G = pictureBox1.CreateGraphics();
using (Pen pen = new Pen(Color.Red, 2))
{
G.DrawRectangle(pen, Rec);
}
G.Save();
pictureBox1.SuspendLayout();
pictureBox1.Invalidate();
}
}
private void pictureBox1_Paint(object sender, PaintEventArgs e)
{
pictureBox1.Update();
}
The reason why your drawings are getting erased is because you're drawing into a Graphics object you obtained by calling the CreateGraphics method. In particular, this line of your code is incorrect:
Graphics G = pictureBox1.CreateGraphics();
As you've discovered, whenever the form is repainted (which happens when it is maximized, minimized, covered by another object on the screen, or in a number of other possible situations), everything that you've drawn into that temporary Graphics object is lost. The form completely repaints itself with its internal painting logic; it's completely forgotten about what you temporarily drew on top of it.
The correct way to draw persistent images in WinForms is to override the OnPaint method of the control that you want to draw onto (or, you could also handle the Paint event). So, if you wanted to paint onto your form, you would place your drawing code into the following method:
protected override void OnPaint(PaintEventArgs e)
{
// Call the base class first
base.OnPaint(e);
// Then insert your custom drawing code
Rec = new Rectangle(UpX, UpY, DwX - UpX, DwY - UpY);
using (Pen pen = new Pen(Color.Red, 2))
{
e.Graphics.DrawRectangle(pen, Rec);
}
}
And to trigger a re-paint, you just call the Invalidate method in any of the mouse events (MouseDown, MouseMove, and MouseUp):
this.Invalidate();
Note, however, that there's absolutely no reason to call the Update method in the Paint event handler. All that calling the Update method does is force the control to repaint itself. But that is already happening when the Paint event gets raised!