.net Resizing control won't work? - c#

I have a couple of pictureboxes that need to be resized by aspect ratio when the window size changes. I assumed I can anchor the width, but set the height manually (i.e. anchor the left, right, and top edges; but not the bottom.) However, my control won't resize if I try changing the Size property. Why wouldn't that work? How can I resize my control?
private void Form1_Resize(object sender, System.EventArgs e)
{
int oldWidth = 1280;
int oldHeight = 1024;
int newWidth = webcamPictureBox.Size.Width; // this is auto-resized w/ window; becomes 591
int newHeight = (oldHeight * newWidth) / oldWidth; // this is calculated manually; becomes 472
// Control won't resize if I change the Size property
// Size property stays the same
this.webcamPictureBox.Size = new Size(newWidth, newHeight);
this.thumbnailPictureBox.Size = new Size(newWidth, newHeight);
}

You could be running into one of a few problems, I suppose:
What's the SizeMode of the PictureBox? Is it AutoSize, StretchImage, or something like that? It should probably be Normal for what you want to do.
Are you sure you have your anchoring set up correctly?
Did you debug and check the final size of the picture boxes you're trying to resize? You should verify that it's what you expect and that the form has been repainted.
These are just some ideas; your code along is not enough to provide a great response.

It's difficult to answer this question definitively with the information you've posted.
Windows forms controls problems are difficult to debug by nature because of all the controls that might be affecting what you're doing. First off, you'll want to try debugging this on your own on a form with as few controls as possible. Are there any circumstances under which the resizing behaves properly?
That said, is the Dock property set on these controls? They definitely won't resize if they're set to DockStyle.Fill.

Thanks for the ideas -- they pointed me on the right track! Everything was set up as they should be, except the TableLayoutPanel they were in was constraining their sizes. I determined this by noticing the pictureboxes' size values were simply uneditable, both in runtime and in the designer.
So I set TableLayoutPanel's AutoSize to true, and it works great!

Related

Set MinimumSize according the controls residing inside form

Title of my question could be make it look like a duplicate but please read ahead as my problem is a bit different.
I am trying to replicate the minimum size functionality of some popular media players like MPC-HC or VLC where when you try to make it small the minimum size it achieves is when only MenuStrip and Player Controls are visible.
The code I've written to attain this is:
public NewMain()
{
InitializeComponent();
int ClientTop = RectangleToScreen(ClientRectangle).Top;
int height = menuStrip1.Height + panel1.Height + ClientTop - Top;
label4.Text = height.ToString();
MinimumSize = new Size(373, height);
}
The problem is that when it runs, its not working perfectly and the menuStrip1 is still getting blocked a little at bottom from the panel1 (Docked at bottom) where the player controls will be placed.
Below is the Image of what I was able to attain with above code.
Next Image is what I expected:
Note that label on left updates when resize the form and the label on the right is the determined height via code.
My Idea was to add the difference of Form's Top and the Top of total rectangle visible on the screen i.e. the height of the title bar otherwise the resulting height will be even smaller and hide the menuStrip1 completely. I don't want to hardcode any values because it'll make the interface less adaptable to the changes that I might be doing later on.
To correctly determine the minimum height in this case is to keep the calculations relative which can be attained by:
int height = Height - (panel1.Top - menuStrip1.Bottom);
All credit goes to Hans Passant who provided this code. I'm just posting it as an answer to mark my question solved. Thank you.

Form.Width incorrect on Form.FormClosing()

I am trying to get an accurate Form.Width on FormClosing().
I have a zoom() method I use to scale a picture in the Form. The form's width is then manually re-sized by me to fit. I then, set the MaximumSize's Width limit to the new width of the form. For our purpose, let's say the width and maxwidth are now 1386.
If I re-size the form in the Windows interface by dragging its edge to the left, the width is being reduced just fine. FormClosing reports the re-sized width accurately. Let's say 1107.
However, if go through the zoom() method I wrote, even though I drag to the left to the same position, FormClosing is reporting the ORIGINAL 1386 width. The only things I do to form size in the zoom() method are set width and maxwidth.
I am at a loss to handle this behavior. I need FormClosing to report the correct size. I think FormClosing is setting the Width to MaximumWidth when it fires. I think I read something about how the Form is set to Hidden by the time the FormClosing event is fired. Maybe being Hidden reverts its size to MaxWidth.
Any help would be much appreciated. I have been struggling with this for a few hours and can't find anything.
Thanks.
Here is the relevant code:
private void zoom()
{
// Re-size form width to slightly more than page width.
// This is percentage-based, meaning 100 = default size.
Size picSize = new Size
{
Width = (int)(originalRenderingSize.Width * integerUpDownZoom.Value / 100),
Height = (int)(originalRenderingSize.Height * integerUpDownZoom.Value / 100),
};
// some code here which I commented-out, and still, the problem exists.
// Set maximum to prevent ugly sizing.
this.MaximumSize = new Size(picSize.Width + 40, Screen.FromControl(this).WorkingArea.Height);
// The problem is this: When this method processes, as shown, a page is rendered and sized according to
// a user-provided zoom level represented by an integerUpDown control. Once rendered, the form should
// re-size its width to match the newly-scaled page's width. This works, too. So far, so good.
//
// But!!! If the user grabs the right side of the form and drags it to the left to reduce the width
// of the form (mind you, this is Windows OS doing this), upon Form.Form_Closing(), you can see a
// quick flash of the form fully-open and unscrolled. Then, in the FIRST line of Form_Closing(),
// the debugger reports the form's width as the fully-open and UNSCROLLED width.
//
// The goal is to set the width upon the conclusion of this zoom, but then, on closing
// get the width of the Form in order to persist it for use the next time the app is run.
//
// 2 options have been tried. Both cause Form_Closing to erroneously report the fully-open width.
// But if BOTH are commented-out, the re-sizing occurs and Form_Closing() reports properly the
// form's scrolled width.
// Bear in mind that Form_Closing is one of those things that can happen anytime or never. This means
// the bug is triggered by EITHER and ONLY the two options below.
// Option 1: Tried first. It sets the width fine.
//
// this.Width = picSize.Width + 40;
// Option 2: It also sets the width fine.
// I think this option causes width to change (it invokes width change, and somewhere in the
// OS's width change, the error occurs.
//this.MinimumSize = new Size(MaximumSize.Width - 1, this.Height);
//this.MinimumSize = new Size(0, 0);
}
Edit: I have new information which should help. The culprit is FormClosing(). Here's what I did: I re-sized the form in Windows until it occupied maybe 500 pixels in width. The horizontal scrollbar on my panel was showing. Then, in the FormClosing event, I added the line: Form.Show(). After that, I put a MessageBox.Show("Hi."). Sure enough, the Show() caused the form to repaint in its full, unscrolled width. It did not maintain its scroll state.
I think I have the solution and will post back after trying. Namely, I need to check Scroll values and operate on those values as well.
Edit 2: FormClosing() also re-sets HorizontalScroll.Value and VerticalScroll.Value to 0. This is a bummer! I wonder how to work around this. I also looked at e.Cancel, but there seems to be no way to take advantage of it, either. It seems e.Cancel just re-shows() the form in its unhidden state.
Sorry I cannot post the code. It would be pointless anyway. Think about it. The Windows OS handles the resizing. Not me. When the user re-sizes the form, it's all on Windows. If user re-sizes the form to 500 pixels wide, but FormClosing() reports it is 1386 pixels wide, no amount of my coding will show us anything new. This is a behavior issue. There is no code to show you how the Windows OS handles form re-sizing.
On FormClosing Event Use:
MessageBox.Show(this.Width.ToString());
You're using another Instance of your form's class, Form.Show() should not work in this event cause Dispose function is called and if you have referenced the same instance it will be disposed as well.

Why Image size is NaN (wpf) and how to resize via mouse wheel?

I want to load an image and put it into a viewbox. The image is displayed correctly, but, when I'm going to get it's width and height, it's both NaN.
This is my image load code :
Image img = new Image();
img.Source = (ImageSource)new ImageSourceConverter().ConvertFromString("1.png");
Viewbox vb = new Viewbox();
vb.Width = img.Width;
vb.Height = img.Height;
vb.Child = img;
cnv.Children.Add(vb);
The reason I want to get the image width and height is so I could resize it (via viewbox resize) later inside the application.
Any idea how to get the image dimension?
And this is how I'm going to resize it (via mouse wheel)
private void cnv_MouseWheel(object sender, MouseWheelEventArgs e)
{
if (vb != null)
{
vb.Width += Mouse.MouseWheelDeltaForOneLine;
vb.Height += Mouse.MouseWheelDeltaForOneLine;
}
}
And it returns error and said that vb.Width is not a valid value.
Questions to sum this up :
How to get the image width / height in wpf?
How to resize the viewbox (which will also result in image resize) via mouse wheel? For example, if I scroll up the wheel, the width and height is added by 1, and if I scroll down the wheel, the width and height is reduced by 1.
Thank you
P.S. Viewbox vb; and Image img; is a global variable, I just shorten the script down.
P.S.S. I know if the Viewbox width and height initialized by a number, lets say 100 and 100, it will work, I just wanna know how to get the image original size.
EDIT :
The resize can be achieved by detecting whether it's scrolled up or down by detecting e.Delta > 0 or e.Delta < 0
(Source : http://social.msdn.microsoft.com/Forums/vstudio/en-US/170c4fd0-1441-4d83-903d-594af75f8fb4/detect-mouse-scroll)
It seems as though the Image object is not fully loaded at that stage. I believe that you can use the Width and Height properties of the ImageSource class instead. That should be fully loaded at this stage.
ImageSource.Width Property
ImageSource.Height Property
For other users, you can also possibly find the values that you want from the ActualWidth and ActualHeight properties of the Image class (inherited from the FrameworkElement class) instead of the more usual Width and Height properties.
FrameworkElement.ActualHeight Property
FrameworkElement.ActualWidth Property
The image original size can only be obtained in Pixels while your WPF controls are measured in Device Independent Pixels so you're going to have to make a translation from Pixels to Device Independent Pixels and back wherever necessary.
That said, to obtain the width and height for a png file, you can load it into a BitmapImage instead of Image and query the PixelWidth and PixelHeight properties for the BitmapImage.
Again, be aware that this is the only place in your code where you're going to be dealing with Pixels, all Width and Height properties (including ActualWidth and ActualHeight, only set after the control is fully rendered) are measured in Device Independent Pixels. This can be misleading because in a lot of situations this happens to be a 1:1 conversion but this is not guaranteed to be the case.
More info can be found here: http://msdn.microsoft.com/en-us/library/windows/desktop/ff684173%28v=vs.85%29.aspx

How to determine the proper maximum value for scrollbar c# .NET (how does windows do it?)

Before I go into my question, let me explain my setup:
First: I have a PictureBox that holds a Bitmap which is generated at runtime. This Bitmap can be different widths but always the same height.
Second: PictureBoxes do not support scrolling, therefore, I have the PictureBox docked in a panel. Initially, I had used the panel's autoscroll feature, but abandoned that after I discovered through this article that PictureBoxes have a size limit. I also learned that it's better to instead have small PictureBoxes and only draw what needs to be seen instead of the whole image.
Third: So I added a HScrollBar, which is fine and dandy, but I can't seem to figure out the math behind how big to make the scroller. I tried setting the maximum of the scrollbar to the length of the bitmap, but as you can see the size of the scroller is much smaller in mine than the one Windows puts in if I use the autoscroll feature.
My question is, what is the math behind the scroller size and how do I emulate that in my custom scrollbar?
Let me know if my question is unclear and I will try my best to make it more understandable. And thanks in advance for your help!
I figured out what was the problem. Perhaps I should have tried a little longer. :)
The answer lies in the LargeChange property. I let the Maximum at the total width of the bitmap and then set the LargeChange to the width of what I wanted to show. (i.e. the width of the PictureBox)
The size of the "scroller" is determined by the ratio of the value of LargeChange to the value of Maximum. For example, if the width to show (LargeChange) is 100 and the total width (Maximum) is 300 then the "scroller" size will be 1/3 of the scrollbar length. (100/300).
I got same problem too and tried to figure it out, I have a panel which contain another panel inside it called panelChild, and the default scrollbar is small, I need lager scrollbar, so I use HScrollBar to do that (display over-top of default scrollbar), I post my solution here, may be it helpful to someone
public Form() {
InitializeComponent();
hScrollBar.Maximum = panelChild.Width;
hScrollBar.LargeChange = panel.Width; // panel which contain panelChild, and this hScrollBar will same as panel scrollbar
hScrollBar.Scroll += HScrollBar_Scroll;
}
private void HScrollBar_Scroll(object sender, ScrollEventArgs e)
{
int diference = e.OldValue - e.NewValue;
foreach (Control c in panel.Controls)
{
c.Location = new Point(c.Location.X + diference, c.Location.Y);
}
}

Why does this code to resize the height a .NET Form make the form too small?

My intent is that the form be sized large enough to show the entire "buttonOK", but not much larger. What actually happens is that the resized form ends up to small to even show the button at all.
public MyFormDlg()
{
InitializeComponent();
this.Height = this.buttonOK.Bounds.Bottom + SomePadding;
The Height property includes the height of the Window's Title bar, thus the client area (the one the button bounds are relative to) is smaller than you expect.
This works:
this.ClientSize = new Size(this.ClientSize.Width,
this.buttonOK.Bounds.Bottom + SomePadding);
I didn't find a ClientHeight property, can this be done any simpler?
why not use the button's height property?

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