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How to make graphics (Shape, animation) in c#

How to make a circle with text inside ?? then move it from one location to another, and then access it later (to delete it).
I want to make something like this

Your question is really very broad and you got a few nice links you should study to learn all about GDI+ drawing.
But if taken literally there is a slightly exotic alternative which puts the burdon of most chores onto the Chart control from DataVisualization.Charting.
You can create EllipseAnnotations and add them to a Chart control.
Disable the Axes and clear the Legends and then use code like this to add a moveable circle wit thext inside:
EllipseAnnotation ea = new EllipseAnnotation();
ea.X = 11; // put at..
ea.Y = 11; // 11% of the chart's area
ea.AllowMoving = true;
ea.BackColor = Color.BlanchedAlmond;
ea.Text = (chart1.Annotations.Count + 1) + "";
chart1.Annotations.Add(ea);
Note that there are quite a few annotation types available. which allow you to add Rectangles, Images, Polygons, Lines and pure Text.
And another pro is that saving or loading the graphics takes only one line each, as you can serialize a Chart out of the box!
:-)

GraphX for .NET is an advanced open-source graph layout and visualization library that supports different layout algorithms and provides many means for visual customizations It is capable of rendering large amount of vertices
https://github.com/panthernet/GraphX

To draw shapes follow here.Also you need a complete tut,you can follow here
Some insight is here:
To draw a simple shape at design time Drag the OvalShape or
RectangleShape control from the Visual Basic PowerPacks tab (to
install, see Visual Basic Power Packs Controls)in the Toolbox to a
form or container control.
Drag the sizing and move handles to size and position the shape. You
can also size and position the shape by changing the Size and Position
properties in the Properties window To create a rectangle with rounded
corners, select the CornerRadius property in the Properties window
and set it to a value that is greater than 0. In the Properties
window, optionally set additional properties to change the appearance
of the shape. To draw a simple shape at run time On the Project
menu, click Add Reference. In the Add Reference dialog box, select
Microsoft.VisualBasic.PowerPacks.VS, and then click OK. In the Code
Editor, add an Imports or using statement at the top of the module:
using Microsoft.VisualBasic.PowerPacks; Add the following code in an Event procedure:
ShapeContainer canvas = new ShapeContainer();
// To draw an oval, substitute
// OvalShape for RectangleShape.
RectangleShape theShape = new RectangleShape();
// Set the form as the parent of the ShapeContainer.
canvas.Parent = this;
// Set the ShapeContainer as the parent of the Shape.
theShape.Parent = canvas;
// Set the size of the shape.
theShape.Size = new System.Drawing.Size(200, 300);
// Set the location of the shape.
theShape.Location = new System.Drawing.Point(100, 100);
// To draw a rounded rectangle, add the following code:
theShape.CornerRadius = 12;
Customizing Shapes When you use the default settings, the OvalShape and RectangleShape controls are
displayed with a solid black border that is one pixel wide and a
transparent background. You can change the width, style, and color of
the border by setting properties. Additional properties enable you to
change the background of a shape to a solid color, a pattern, a
gradient fill, or an image. Before you change the background of a
shape, you should know how several of the properties interact. The
BackColor property setting has no effect unless the BackStyle property
is set to Opaque. If the FillStyle property is set to Solid, the
FillColor overrides the BackColor. If the FillStyle property is set to
a pattern value such as Horizontal or Vertical, the pattern will be
displayed in the FillColor. The background will be displayed in the
BackColor, provided that the BackStyle property is set to Opaque. In
order to display a gradient fill, the FillStyle property must be set
to Solid and the FillGradientStyle property must be set to a value
other than None. Setting the BackgroundImage property to an image
overrides all other background settings.
This SO link I found is also nice here

Background Panel Windows Form

I hope you can help me with this problem, attached videos to explain in a simpler way.
First example
Panel (has a textured background) with labels (the labels have a png image without background)
Events: MouseDown, MouseUp and MouseMove.
As you will notice in the video to drag the label the background turns white panel and regains its background image when I stop dragging the label
Panel controls have a transparent background as property, but changing the background with any color, let the problem occurred related to the substance, I do not understand why this happens and how to fix less.
Second Example
Contains the above, with the only difference that the panel controls instead of having transparent background, I chose black color for that property

You have to use double buffer and you don't have to stop using an image on the background, you can have everything running smoothly.
You have a couple of ways to do this, the fast way (not enough most of the time) is to enable doublebuffer of the panel.
The "slow" but better way is to do your own Double Buffer using a Bitmap object as a buffer.
This example creates a "side buffer" and accepts an image as parameter and draws it using created buffer.
public void DrawSomething(Graphics graphics, Bitmap yourimage)
{
Graphics g;
Bitmap buffer = new Bitmap(yourimage.Width, yourimage.Height, graphics);
g = Graphics.FromImage(buffer);
g.SmoothingMode = System.Drawing.Drawing2D.SmoothingMode.HighQuality;
g.DrawImage(yourimage, 0, 0);
graphics.DrawImage(buffer, 0, 0);
g.Dispose();
}
Call this on your OnPaint event.
BTW... this is just a double buffer example.
Cheers

Change DoubleBuffered to true for both form and panel. I think that should solve your problem.

this is totally normal, because System.Windows.Forms.Control based items were not designed to do this kind of advanced Graphics operations.
in fact the reason that this effect happens here, is that when you assign any value other than 255 to the alpha component of a control BackColor, the form does the following when you change the control size or position:
it sets the new control position
it redraws the parent control
it gets the background of the control's parent as an image
it draws acquired image into the control body to seem as if the control is transparent
the control body gets drawn on top of the previously drawn background
the control children are drawn
* this is is a simplified explanation for the sake of illustration to deliver the idea
steps 1, 2 are responsible for the flickering effect that you see.
but you have two ways to solve this,
-the first is some kinda advanced solution but it's very powerful, which is you would have to create a double buffered custom control that would be your viewport.
the second is to use WPF instead of windows forms, as WPF was designed exactly to do this kind of things.
if you can kindly provide some code, i can show you how to do both.

Redraw panel contents after ClientSizeChanged

So my application runs in fixed size window and in full screen. The problem I'm facing is how to properly scale the current contents of the panel (which depend on the application use) when the window is resized. This is my current code:
private void Form1_ClientSizeChanged(object sender, EventArgs e)
{
System.Drawing.Drawing2D.Matrix transformMatrix = new System.Drawing.Drawing2D.Matrix();
float px = panel2.Width;
float py = panel2.Height;
panel2.Width = this.Width / 2;
panel2.Height = panel2.Width;
panel2.Location = new Point(this.Width - panel2.Width - 30, 30);
transformMatrix.Scale(panel2.Width / px, panel2.Height / py);
panel2.Region.Transform(transformMatrix);
//Rest of the code
}
But the drawn content doesn't scale, and if I use Invalidate() or Refresh() the drawn content gets cleared (the panel is redrawn empty). What am I missing?

.NET doesn't remember what's drawn on the panel, as simple as that. As soon as anything invalidates the windows bitmap buffer (causing a WM_PAINT), it's going to be repainted again. So, you have to draw what you want to draw using the Paint event (or overriding OnPaint).
However, there is another way that might be easier to implement - don't paint into a Panel. Instead, paint into a PictureBox (or rather, a Bitmap assigned to the Image property of the PictureBox). The Bitmap will be reused when invalidating (and redrawing) the picture box, so nothing will be lost. By using PictureBox.ScaleMode, you can define how you want the picture box to scale the bitmap, and it will do so as well as it can.
In any case, transforming the Region property doesn't do anything useful - you're simply changing the region, not doing anything to the drawing itself. To use 2D transformation matrices, you want to apply them on a Graphics object during the drawing (in Paint handler or OnPaint override) - drawing anything on the Graphics object will then transform everything you're trying to draw, which in your case means scaling the painting.
So you have to decide: do you want to just scale a stored bitmap with the painted image, or do you want to redraw it all from scratch (which also means you can pick any level of detail you can provide)?

I think that you're mistaking what the Region property is meant for. According to the MSDN docs (empasis mine, replace 'window' with 'control' when reading):
The window region is a collection of pixels within the window where the operating system permits drawing. The operating system does not display any portion of a window that lies outside of the window region. The coordinates of a control's region are relative to the upper-left corner of the control, not the client area of the control.
All that you're doing is changing the region that the OS will allow painting, which explains why you're not seeing anything. I think that you should be resizing the control when the form is resized, either through Anchor, or through my preference of Dock with several controls, or a panel like TableLayoutPanel where it will handle scaling and relative sizing for you.

Thank you for your answers, but I wrote my own function and logic that serves the purpose for this application. Basically the function checks for the state of the application variables, and calls the appropriate function that originally drew the content, and since those functions use the panel width and height as arguments they properly scale the drawn content and retain the drawing composition.
P.S. I'll accept Luaan's answers since it offers a valid alternative and is complete.

How to retrieve the visible area/areas of a WPF control overlapped by other controls considering transparency?

I need to determine the visible area/areas of a WPF control overlapped by other controls taking in consideration transparency.
Consider the following scenario:
Three controls on a canvas. The blue and the green one are overlapping the third one. The green one has a transparent rectangle area. Is it possible to problematically get the visible regions 1, 2, 3 marked by red rectangles?
Something similar to (following API doesn't exist):
Geometry[] visibleAreas = VisualTreeHelper.GetVisibleGeometry(controlInTheBack);
Thanks in advance for any suggestions.
Update:
I've tried to use DrawingGroup drawingGroup = VisualTreeHelper.GetDrawing(visual) to get the geometries of each control.
Then use CombinedGeometry with GeometryCombineMode="Union" on the overlapping controls to get the overlapping area.
Then use CombinedGeometry with GeometryCombineMode="Exclude" between the geometry of the control in the back and the result of the union to obtain the visible regions.
The problem is that VisualTreeHelper.GetDrawing(control) returns null.

Have you already tried to use HitTest? It may be helpful
http://msdn.microsoft.com/en-us/library/ms752097.aspx

How do I make a form transparent while keeping the controls fully visible?

I would like to have a form in which the controls on the form are fully visible but the form itself is invisible. If I change the form's Opacity, this makes both the form and the controls on it semi-transparent, so this doesn't work.
I can't do this by setting the form's TransparencyKey, since I have a PictureBox on the form. If the image in the PictureBox happens to contain pixels that match the TransparencyKey, they appear as openings in the form, which I don't want.

TransparencyKey is the only way to get this. Pick the right color. Color.Fuchsia has a long tradition of being the color of choice, going back to the early days of Win32 development. Assault your eye with it to see its merits.

With the caveat that I've never used it, just ran across it once, thought "neat!" and moved on...
Look into System.Drawing.Drawing2D.GraphicsPath and setting the form's Region property. I added two buttons to the basic Windows forms application:
public Form1()
{
InitializeComponent();
Rectangle r1 = new Rectangle(button1.Location, button1.Size);
Rectangle r2 = new Rectangle(button2.Location, button2.Size);
GraphicsPath gp = new GraphicsPath();
gp.AddRectangle(r1);
gp.AddRectangle(r2);
this.Region = new Region(gp);
}
I've approximated the shape of the button with a rectangle; with this code, you can see the form background color at the buttons' corners. You'll need to work out the enclosing path for each of your controls and add them to the path individually. You'll need to take into account any offset introduced by the form title bar or border style.
Update: I did some investigation and have a couple of possible approaches for the problem:
Using the GraphicsPath method, set pictureBox.Visible to False if there is no image loaded.
When you load an image into the picture box, analyze the image to get a list of all the colors in it, then randomly generate one that isn't. Set the form's BackColor and TransparencyKey properties to match this new color, Hans Passant's answer.