Develop Reference

How to determine if control is outside of Form?

I am trying to determine if a dynamically added control is outside of the form.
At first, I thought it might be possible to calculate it by getting the height of the form, and location of the dynamically added control.
But I noticed that the Control.Location and Form.Height have "nothing" in common.
I don't think I really understand what the correlation is between Height and Location.
For example:
I thought that if your form has a height of 500, and I put the control at the bottom of the form, it should give the Location: X, 500 (X is width, not relevant here). But this is not correct, it shows me for example: X, 465. Am I missing something?
So I need to be able to recognize if the control is outside of the form, even if it's just one pixel.
I've found several similar questions here on SO, yet this does not really give me the answer that I need, unfortunately.
So, is there any way to do this? Is it possible to calculate it?

The Height of the form also includes the height of the title bar and borders.
You can use the ClientSize of the form:
From the documentation on MSDN:
The size of the client area of the form is the size of the form excluding the borders and the title bar. The client area of a form is the area within a form where controls can be placed. You can use this property to get the proper dimensions when performing graphics operations or when sizing and positioning controls on the form. To get the size of the entire form, use the Size property or use the individual properties Height and Width.
The position of the control is relative to its container, so (0,0) is the left upper corner inside the form.

I know this is an older thread, but you can try using this method:
public static bool IsOutofBounds(Form form, Control control)
{
int controlEnd_X = control.Location.X + control.ClientSize.Width;
int controlEnd_Y = control.Location.Y + control.ClientSize.Height;
if (form.ClientSize.Width < controlEnd_X || form.ClientSize.Height < controlEnd_Y)
{
return true;
}
else
{
return false;
}
}
It works for checking whether a control is out of bounds of its parent form.

You could use this code to check if controls is inside form:
var Inside = frm.ClientRectange.Intersect(ctrl.Bounds) == ctrl.Bounds;

the top left corner of a form is (0,0) lower right corner is (formHeight, fromWidth).
to check this place two text boxes on a form and write this code in the mouse move event to see how x and y change.
private void Form1_MouseMove(object sender, MouseEventArgs e)
{
textBox1.Text = e.X.ToString();
textBox2.Text = e.Y.ToString();
}
Note that there is an difference between the number returned from the edge of the form and the size chosen by you. In my 500*500 form it is actually 460*483. the difference is always the same for any border style and any resolution.
To place a control on your form use the location structure in the form or use the top and left properties for the control; top = x, left = y.
Remember your offset from the actual height and width you measured and the dimension of the control.
To add a button with the following dimensions 80*30 in the bottom right corner I would right something like this:
button1.Location = new System.Drawing.Point(402, 430);
bottom left corner:
button1.Location = new System.Drawing.Point(0, 430);

Unable to draw rectangle on WindowsFormsHost using Adorners in WPF

In my WPF application, I have added WindowsFormsHost in one grid, I want to draw a rectangle on the control inside WinFormsHost.
Application layout:
Code I'm trying:
Adorner Class
public class SimpleRectAdorner : Adorner
{
// Be sure to call the base class constructor.
public SimpleRectAdorner(UIElement adornedElement)
: base(adornedElement)
{
}
// A common way to implement an adorner's rendering behavior is to override the OnRender
// method, which is called by the layout system as part of a rendering pass.
protected override void OnRender(DrawingContext drawingContext)
{
Rect adornedElementRect = new Rect(this.AdornedElement.DesiredSize);
// Some arbitrary drawing implements.
SolidColorBrush renderBrush = new SolidColorBrush(Colors.Green);
renderBrush.Opacity = 0.2;
Pen renderPen = new Pen(new SolidColorBrush(Colors.Navy), 1.5);
// Draw a circle at each corner.
Rect rect = new Rect(new Point(adornedElementRect.TopLeft.X, adornedElementRect.TopLeft.Y + 50), new Size(150, 50));
drawingContext.DrawRectangle(renderBrush, renderPen, rect);
}
}
Code to add adorner
private void btnDraw_Click(object sender, RoutedEventArgs e)
{
AdornerLayer.GetAdornerLayer(viewerGrid.Children[0]).Add(new SimpleRectAdorner(viewerGrid.Children[0]));
}
Is there any possible way to draw a rectangle on Control which is inside WindowsFormsHost?
Thanks in advance.

As noted in the comment by Clemens, WindowsFormsHost is rendered separately from the rest of your Window, and by necessity it is rendered on top of the Window. At first glance, this seems to be a design limitation about which you can do nothing; however, that is not strictly true.
If a second layer is added over your first layer, simply add a third layer on top of the second. Another Window or a Popup can render over the top of your WindowsFormsHost, and while you will have to jump through some hoops to make it all seem like part of the same Window--ensuring everything moves, minimizes, and restores at the same time, etc--it is certainly possible to do so.
You can use transparency in your third layer to allow the content in the WindowsFormsHost to show and be accessed. For example, you can set AllowsTransparency to true on your WPF Popup. It will be a bit of extra work, but if you absolutely need this feature, you can do it.

Winforms: How to draw line over control without invalidating it

i have a class that draws waveforms of audio. I'm drawing it in OnPaint function. Now i need to draw a line that shows where on the waveform we are at current moment. I can calculate the position but when i try to draw it i need to call Invalidate() and that forces form to redraw all that waveform chart data (a lot of points).
So is there a way to put some transparent element over this one and then call Invalidate() only on that element? i was trying with picture box but no sucess...
//main form
private void timer100ms_Tick(object sender, EventArgs e)
{
customWaveViewer1.currentPosition = (int)((stream.Position / (float)stream.Length) * customWaveViewer1.Width);
customWaveViewer1.overlayLabel.Invalidate(false);
}
//drawing function in my class
private void overlayLabelInvalidate(object sender, PaintEventArgs e)
{
Pen pen = new Pen(Color.FromArgb(255, 0, 0, 0));
e.Graphics.DrawLine(pen, currentPosition, 0, currentPosition, this.Height);
}
//constructor
public CustomWaveViewer()
{
InitializeComponent();
this.DoubleBuffered = true;
this.PenColor = Color.DodgerBlue;
this.PenWidth = 1;
overlayLabel = new PictureBox();
overlayLabel.Size = new System.Drawing.Size(this.Width, this.Height);
overlayLabel.Location = new Point(this.Left, this.Top);
overlayLabel.Visible = true;
overlayLabel.BackColor=Color.FromArgb(0,0,0,0);
overlayLabel.Paint += new System.Windows.Forms.PaintEventHandler(this.overlayLabelInvalidate);
Controls.Add(overlayLabel);
}

Actually what you are saying is not exactly true.
In the painteventargs there is a rectangle indicating the small portion of the window that needs to be repainted.
Also when you invalidate, you don't necessarily need to invalidate the whole form.
In your case you might want to invalidate only the old and new position of the marker that indicates where you are in the waveform.
So in your algorithm of your paint method, it is really up to you to make it efficient and only paint that part of the window that really needs repainting and to skip the part that does not need repainting.
It really can make a huge difference.
To make it even more look professional, set double buffering on.
No need to hastle with bitmaps of the whole image you have yourself, that is just what double buffering is all about, and forms can do it for you.
I copied following excerpt from https://msdn.microsoft.com/en-us/library/windows/desktop/dd145137(v=vs.85).aspx
BeginPaint fills a PAINTSTRUCT structure with information such as the dimensions of the portion of the window to be updated and a flag indicating whether the window background has been drawn. The application can use this information to optimize drawing. For example, it can use the dimensions of the update region, specified by the rcPaint member, to limit drawing to only those portions of the window that need updating. If an application has very simple output, it can ignore the update region and draw in the entire window, relying on the system to discard (clip) any unneeded output. Because the system clips drawing that extends outside the clipping region, only drawing that is in the update region is visible.
In this case there is no simple output and taking this into account is adviced.
I am not saying that creating a bitmap will not work. I am saying that optimizing your drawing logic will solve it just as well.
The information above still stands as windows forms is built on top of the old win32 api.

Restricting usercontrol from moving beyond the canvas xaml

I am developing Windows 8.1 Store Apps using XAML.
The scenario is I am having a Canvas in which I am placing more than one user controls. The user controls can be moved on click of a button. I should restrict the user controls from moving beyond the Canvas. What is the way to do it.? I am having Manipulation events within the usercontrol for movement.

I expect that your controls that you move are children from the canvas?
If so i think you can do a check to see if the bounds of you control moving on your canvas hits the border of you canvas. If this is happening then make it stop.
Basic gameprogramming stuff. I will look for a example

Here it is.
This part of code will get you the place of your control inside your container
public static class BoundsHelper
{
public static Rect GetBoundsInParentContainer(Control control)
{
Vector offset = VisualTreeHelper.GetOffset(control);
Rect rect = new Rect(offset.X, offset.Y, control.ActualHeight, control.ActualWidth);
return rect;
}
}
So if you have a button in the top left corner of the canvas and you ask that button the control where it is it will give you a rect where the X and Y are 0 and the Width and Height of your control. So if you move your control inside your canvas. Call this method and check if your control is still inside the Height and width of your canvas.
Here the code to move to the right but first check if you are allowed to move
private void MoveRightAndCheck(Rect boundsControl, Control container)
{
int stepSize = 10;
if (container.ActualWidth > (boundsControl.X + boundsControl.Width + stepSize))
{
//Your code to move your control inside the canvas
}
}

Simple rectangle box

How do put rectangular box around few controls on my winform? (i dont want the grouping thing).

If you don't want to use a GroupBox, you can put your controls in a Panel and set its BorderStyle property to BorderStyle.FixedSingle or BorderStyle.Fixed3D.

What's wrong with the GroupBox control? Grouping together a related set of controls is exactly what it's intended for. Your users have seen it in every other application they use, and throughout the Windows shell. They're much more likely to recognize what it means than your own custom-drawn rectangle. Deviating from standard platform conventions is rarely a good idea. I strongly recommend using the GroupBox control, even if it's not exactly the perfect look that you had in mind.
That being said, it's certainly possible to draw your own box around a group of controls on a form. To do so, you'll need to override your form's OnPaint method and write some code to draw a rectangle. Doing it this way gives you complete control over the color of your box, as well as the line thickness.
protected override void OnPaint(System.Windows.Forms.PaintEventArgs e)
{
// Call the base class
base.OnPaint(e);
// Create your drawing pen
using (Pen p = new Pen(SystemColors.WindowText, 2.0))
{
// Calculate the position and dimensions of the box
Rectangle rect = new Rectangle(10, 10, 30, 30);
// Draw the rectangle
e.Graphics.DrawRectangle(p, rect);
}
}
The only thing you'll need to add is the code that calculates the dimensions of your rectangle, relative to the controls you want it to surround. Use the Location property of each control to get this information.

You can put your controls into a panel and set its BorderStyle from None to FixedSingle - it is the easiest way

http://msdn.microsoft.com/en-us/library/cyh3c8h8.aspx
Pen pen = new Pen(Color.FromArgb(255, 0, 0, 0));
e.Graphics.DrawLine(pen, 20, 10, 300, 100);
You can draw lines on a windows form this way. This would hook into the Paint method where e is PaintEventArgs