Recently I thought: "Let's set the 'resolution' from 16:9 to 16:9(1920x1080)" but i noticed that now all my positioning* code was off, and the size of pictures and text was way too small.
My problem now is, if I should just use the 16:9 aspect ratio or an fixed resolution (I don't know the benefits). But if I shouldn't use the aspect ratio, how to change the fixed resolution when the Project is ready, for example in the settings, without needing to rewrite all my code* and rescale all my images on the Canvas according to the resolution.
*For those of you who don't know what I mean with 'positioning', I mean setting the position of an Image on the Canvas, which obviously needs to be changed because the resolution is different. You could make something that detects your resolution and positions you image based on that, but idk if there is a better solution.
The best way to do this is during positioning ui using procentage also canvas Type which is displayed to resolution.
https://youtu.be/Tys6QWi9RpM
Solution on yt.
I'm making an app for Windows 8.1 where it is important to be able to zoom in and examine images in detail. If I just open up the bitmap and zoom in it looks like.
However when I load the image into my app and use the ScrollViewer to zoom in I get.
As it appears to be trying to interpolate pixel values for some sort of anti-aliasing.
How can I get it so that when I zoom in it shows (as best it can) the exact pixels of the image? In particular I'm using the image as the background to a canvas which is contained in a scroll viewer.
I've looked around on here and MSDN and found a pair of related questions, but as yet they don't seem to have solved my exact problem.
A discussion on WPF
A similar issue with a canvas
Older related question on pixel art
A way to use bitmap encoding (which I couldn't get to work)
Similarly phrased question
There is no easy way to go about this, your best option is to use DirectX to render the image much larger so that you can mitigate the effect of WinRT automatically interpolating pixel values.
As someone explained on MSDN and based on this outstanding request I can't see any other way to accomplish this.
Use Win2D
Win2D is a DirectX inter-op library for WinRT. With this you can render the image at a much larger size, and then set the default zoom level for the scrollViewier to be very small. Because of this when you zoom in it will appear to be that you can see the individual pixels without any fuzzy/blurry interpolation because you will actually be seeing groups of 64 pixels or so all as one color. I couldn't find any way to actually override what kind of interpolation gets done so this seems to be the best method.
Download Win2D as a NuGet package using Visual Studio, Win2D's
quickstart guide does a good job explaining some of the setup
Set up your canvas and the draw event and use the DrawImage function to render the image larger
<ScrollViewer x:Name="Scroller" ZoomMode="Enabled"
MinZoomFactor="0.1" MaxZoomFactor="20">
<canvas:CanvasControl x:Name="canvas" Draw="canvas_Draw" CreateResources="create"/>
</ScrollViewer>
In the canvas_draw function.
canvas.Width = original.Width * 10;
canvas.Height = original.Height * 10;
args.DrawingSession.DrawImage(bitmap,new Rect(0,0,original.Width*10,original.Height*10), new Rect(0,0,original.Width,original.Height), 1.0f, CanvasImageInterpolation.NearestNeighbor);
Make sure to set your canvas to be larger as well
In your code behind set the default zoom of your ScrollVieiwer to be appropriate so your image appears to be the same size.
In the page constructor
Scroller.ZoomToFactor (0.1f);
Other Ways Which I Looked Into and Didn't Work
Making the canvas very large and using BitmapEncoder/BitmapDecoder with the interpolation mode set to NearestNeighbor, this introduced lots of visual artifacts even when scaled to a power of 2 size
Render options only appear to be usable in WPF and not WinRT
It may also be possible to use some image manipulation library to simply make the bitmap 10x or so as large and then use that, but I ended up using Win2D instead.
I have a WinForms application that allows you to edit documents. Each document is made of chapters and each chapter holds a collection of RTF blocks. The RTF blocks are loaded in a PanelControl using Dock = DockStyle.Top.
The problem is that when the total height of a chapter gets too large (estimating > 32768 pixels) the lower blocks are not properly docked: they appear behind one another. When trying to isolate the problem I noticed that this also happens with simpler controls like a LabelControl.
Things I tried are methods like Refresh(), Invalidate() and PerformLayout: they will not resolve the issue.
What does help is resizing the form. After that all controls are laid out correctly.
Can anyone help on how to solve this without resizing the form?
Attached a simple demo-project that illustrates the problem.
From my comment above (seems really to be the problem here):
WinForms (and the GDI in general) is often behaving unpredictably if one tries to use coordinates outside a 16 bit range. Try to avoid that. In the range of possible problems are things just not getting drawn at all, OverflowExceptions at unexpected code positions etc.
If it's possible to you take decision to change this layout, I suggest you to take another approach on showing/editing the documents chapters with some kind of pagination or collapsing RTF blocks into a menu and showing only current.
You see.. it makes a sense the height value be a integer 16-bit value.
A screen is way more tiny than this.
As panel height increases to such a high size. You see that using scroll bar will become very very sensible.. and it's not a good thing.
Content with size 2x, 3x, 5x being scrolled is usable to user. But scrolling a content with height (~32768) of at least (using good resolution monitor w/ window maximized) in optimal case 32x the size of window is very uncomfortable.
Plus, I believe that the productivity of user will decrease due to brain difficulty in locate "things" in a increasing collection of "things".
I have a library of a few "custom controls". Essentially we have our own buttons, rounder corner panels, and a few groupboxes with some custom paint. Despite the "math" in the OnPaint methods, the controls are pretty standard. Most of the time, all we do is draw the rounded corners and add gradient to the background. We use GDI+ for all that.
These controls are ok (and very nice looking according to our customers), however and despite the DoubleBuffer, you can see some redrawing, especially when there are 20++ buttons (for example) on the same form. On form load you see the buttons drawing… which is annoying.
I'm pretty sure that our buttons are not the fastest thing on earth but my question is: if double buffer is "on", shouldn't all that redraw happen in background and the Windows subsystem should show the results "instantly" ?
On the other hand, if there's "complex" foreach loop that will create labels, add them to a panel (double buffered) and change their properties, if we suspendlayout of the panel before the loop and resume layout of the panel when the loop is over, shouldn't all these controls (labels and buttons) appear "almost instantly"? This doesn't happen like that, you can see the panel being filled.
Any idea why this is not happening? I know it's hard to evaluate without sample code but that's hard to replicate too. I could make a video with a camera, but trust me on this one, it's not fast :)
We've seen this problem too.
One way we've seen to "fix" it is to completely suspend drawing of the control until we're ready to go. To accomplish this, we send the WM_SETREDRAW message to the control:
// Note that WM_SetRedraw = 0XB
// Suspend drawing.
UnsafeSharedNativeMethods.SendMessage(handle, WindowMessages.WM_SETREDRAW, IntPtr.Zero, IntPtr.Zero);
...
// Resume drawing.
UnsafeSharedNativeMethods.SendMessage(handle, WindowMessages.WM_SETREDRAW, new IntPtr(1), IntPtr.Zero);
One of the things you should look at is whether you have set BackColor=Transparent on any of the child controls of your panels. The BackColor=Transparent will significantly degrade rendering performance especially if parent panels are using gradients.
Windows Forms does not use real transparency, rather it is uses "fake" one. Each child control paint call generates paint call on parent so parent can paint its background over which the child control paints its content so it appears transparent.
So if you have 50 child controls that will generate additional 50 paint calls on parent control for background painting. And since gradients are generally slower you will see performance degradation.
Hope this helps.
I'll approach your problem from a performance angle.
foreach loop that will create labels,
add them to a panel (double buffered)
and change their properties
If that's the order things are done, there's room for improvement. First create all your labels, change their properties, and when they are all ready, add them to the panel: Panel.Controls.AddRange(Control[])
Most of the time, all we do is draw
the rounded corners and add gradient
to the background
Are you doing the same thing over and over again? How are your gradients generated? Writing an image can't be that slow. I once had to create a 1680x1050 gradient in-memory, and it was really fast, like, too fast for Stopwatch, so drawing a gradient can't be so hard.
My advice would be to try and cache some stuff. Open Paint, draw your corners and save to disk, or generate an image in-memory just once. Then load (and resize) as needed. Same for the gradient.
Even if different buttons have different colors, but the same motif, you can create a bitmap with Paint or whatever and at runtime load it and multiply the Color values by another Color.
EDIT:
if we suspendlayout of the panel before the
loop and resume layout of the panel when the loop is over
That's not what SuspendLayout and ResumeLayout are for. They suspend the layout logic, that is, the automatic positioning of the controls. Most relevant with FlowLayoutPanel and TableLayoutPanel.
As for doublebuffering, I'm not sure it applies to custom draw code (haven't tried). I guess you should implement your own.
Doublebuffering in a nutshell:
It's very simple, a couple lines of code. On the paint event, render to a bitmap instead of rendering to the Graphics object, and then draw that bitmap to the Graphics object.
In addition to the DoubleBuffered property, also try adding this to your control's constructor:
SetStyle(ControlStyles.OptimizedDoubleBuffer |
ControlStyles.AllPaintingInWmPaint, true);
And if that ends up not being enough (which I'm gonna go out on a limb and say it isn't), consider having a look at my answer to this question and suspend/resume the redraw of the panel or Form. This would let your layout operations complete, then do all of the drawing once that's done.
You may want to look at the answer to my question, How do I suspend painting for a control and its children? for a better Suspend/Resume.
It sounds like what you are looking for is a "composited" display, where the entire application is drawn all at once, almost like one big bitmap. This is what happens with WPF applications, except the "chrome" surrounding the application (things like the title bar, resize handles and scrollbars).
Note that normally, unless you've messed with some of the window styles, each Windows Form control is responsible for painting itself. That is, every control gets a crack at the WM_ PAINT, WM_ NCPAINT, WM_ERASEBKGND, etc painting related messages and handles these message independently. What this means for you is that double buffering only applies to the single control you are dealing with. To get somewhat close to a clean, composited effect, you need to concern yourself not just with your custom controls that you are drawing, but also the container controls on which they are placed. For example, if you have a Form that contains a GroupBox which in turn contains a number of custom drawn buttons, each of these controls should have there DoubleBuffered property set to True. Note that this property is protected, so this means you either end up inheriting for the various controls (just to set the double buffering property) or you use reflection to set the protected property. Also, not all Windows Form controls respect the DoubleBuffered property, as internally some of them are just wrappers around the native "common" controls.
There is a way to set a composited flag if you are targeting Windows XP (and presumably later). There is the WS_ EX_ COMPOSITED window style. I have used it before to mix results. It doesn't work well with WPF/WinForm hybrid applications and also does not play well with the DataGridView control. If you go this route, be sure you do lots of testing on different machines because I've seen strange results. In the end, I abandoned used of this approach.
Maybe first draw on a control-only 'visible' (private) buffer and then render it:
In your control
BufferedGraphicsContext gfxManager;
BufferedGraphics gfxBuffer;
Graphics gfx;
A function to install graphics
private void InstallGFX(bool forceInstall)
{
if (forceInstall || gfxManager == null)
{
gfxManager = BufferedGraphicsManager.Current;
gfxBuffer = gfxManager.Allocate(this.CreateGraphics(), new Rectangle(0, 0, Width, Height));
gfx = gfxBuffer.Graphics;
}
}
In its paint method
protected override void OnPaint(PaintEventArgs e)
{
InstallGFX(false);
// .. use GFX to draw
gfxBuffer.Render(e.Graphics);
}
In its resize method
protected override void OnSizeChanged(EventArgs e)
{
base.OnSizeChanged(e);
InstallGFX(true); // To reallocate drawing space of new size
}
The code above has been somewhat tested.
I had the same problem with a tablelayoutpanel when switching usercontrols that I wanted displayed.
I completely got rid of the flicker by creating a class that inherited the table, then enabled doublebuffering.
using System;
using System.Collections.Generic;
using System.Text;
using System.Windows.Forms;
namespace myNameSpace.Forms.UserControls
{
public class TableLayoutPanelNoFlicker : TableLayoutPanel
{
public TableLayoutPanelNoFlicker()
{
this.DoubleBuffered = true;
}
}
}
I've had a lot of similar issues in the past, and the way I resolved it was to use a third-party UI suite (that is, DevExpress) rather than the standard Microsoft controls.
I started out using the Microsoft standard controls, but I found that I was constantly debugging issues which were caused by their controls. The problem is made worse by the fact that Microsoft generally does not fix any of the issues which are identified and they do very little to provide suitable workarounds.
I switched to DevExpress, and I have nothing but good things to say. The product is solid, they provide great support and documentation and yes they actually listen to their customers. Any time I had a question or an issue, I got a friendly response within 24 hours. In a couple of cases, I did find a bug and in both instances, they implemented a fix for the next service release.
I have seen bad winforms flicker on forms where the controls referred to a missing font.
This is probably not common, but it's worth looking into if you've tried everything else.
I took this WPF-VS2008 ScreenSaver template and started to make a new screen saver. I have some experience with winForms-platform (GDI+) screen savers, so i am little bit lost with WPF.
Background-element for my screen saver is Canvas.
A DispatcherTimer tick is set to 33 msec, which is ~ 30 FPS.
Background-color is just one huge LinearGradientBrush.
On the screen I have (per available screen, on my local computer i have 2) n-Ellipses drawn with randomly-calculated (Initialization) Background colors + Alpha channel. They are all in Canvas's Children collection.
I'm moving those Ellipses around the screen with some logic (every DispatcherTimer tick). I make a move per-ellipse, and then just call Canvas.SetLeft(...) and Canvas.SetTop(...) for each Ellipse.
If N (number of Ellipses) is higher > 70-80, i begin to notice graphics slow-downs.
Now, i wonder, if there is anything i could do to improve the graphic-smoothness when choosing higher N-values ? Can I "freeze" "something" before moving my Ellipses and "un-freeze" "something" when i'm finished ? Or is there any other trick i could do?
Not that i would be too picky about mentioned performance drop downs - becouse when N==50, everything works smooth as it should. Even if Ellipses are ALL in the SAME place (loads of transparency stuff), there are no problems at all.
Have you tried rendering in the CompositionTarget.Rendering event, rather than in a timer? I've gotten impressive performance in a 3D screen saver when using the Rendering event and doing my own double buffering. (See http://stuff.seans.com/2008/08/21/simple-water-animation-in-wpf/ , http://stuff.seans.com/2008/08/24/raindrop-animation-in-wpf/ , and http://stuff.seans.com/2008/09/01/writing-a-screen-saver-in-wpf/ )
You will improve performance if you call the Freeze method on objects that inherit from Freezable - brushes for example.
The reason is that Freezable supports extra change notifications that have to be handled by the graphics system, when you call Freeze the object can no longer change and so there are no more change notifications.
For an example of this notification system, if you create a brush, use it to paint a rectangle (for example) and then change the brush the on-screen rectangle will change color.
It is not possible to unfreeze something once it has been frozen (although a copy of the object is unfozen by default). Double buffering is also enabled by default in WPF so you cannot gain here.
Once way to improve performance if not already done is to use geometry objects such as Ellipse Geometry rather than shapes if you do not need to the all of the events as these are lighter weight.
I also have found this MSDN Article Optimizing Performance: 2D Graphics and Imaging that suggests a CachingHint may help along with some other tips.
Finally ensure that you are using the latest service pack one as it has many performance improvements outlined here