Can't consistently maximize WPF window - wpf

I have a minimized WPF window. I click the item in the taskbar to maximize. It makes a little audio ding, then I try again, and again. Usually about the third try it will maximize. What could cause it to refuse my initial maximize attempt?

One possibility is that you have some code that's changing the value of the ResizeMode property to NoResize.
See this page for more: http://msdn.microsoft.com/en-us/library/ms748948.aspx
Second, you might be overriding OnStateChanged and not calling base.OnStateChanged() consistently.
Third, you may have something hogging the UI's thread during your first attempts. Once that task--whatever it is--stops blocking then WPF can repaint the window in restored/maximized state.

I had a similar problem when trying to manually maximize a custom window.
The solution was to put the next code in my maximize button...
this.SizeToContent = System.Windows.SizeToContent.Manual;
this.MaxWidth = double.PositiveInfinity;
this.MaxHeight = double.PositiveInfinity;
this.Width = double.NaN;
this.Height = double.NaN;
this.WindowState = WindowState.Maximized;
Where 'this' referes to the Window.

Related

Prevent redraw of window when resizing grid row/column

WPF grid container, with multiple rows/columns with usercontrols loaded in the sections.
Some rows/columns are expanded/collapsed by setting the Column/Row width (from 0 to 125* or a fixed value), based upon a button click.
Simple example code:
If colgrdFolder1.Width.Value Then
Me.Width = Me.Width - colgrdFolder1.ActualHeight
colgrdFolder1.Width = New GridLength(0)
Else
Me.Width = Me.Width + 150
colgrdFolder1.Width = New GridLength(150)
End If
This works, but when the parent resizes, it flashes as the column/row is set. When the parent Width is first increased you can see the grid resize and then when the new colWidth is set, it resizes (and flashes) again.
Is there not a property/method to freeze the window/prevent redraws until the resize is complete?
I think there are BeginInit() and EndInit() methods, that should do what you want (prevent redraw), but in my experience they haven't really worked (maybe I have used them incorrectly).
I don't know of any other way of preventing redraw, perhaps someone who is more of an expert in WPF can shed some more light...

How to accelerate WPF fade in/out animation

I implemented lightbox effect with window's opacity change whilst fading in/out. When I have my window maximized this effect has big delay or when I use duration property then opacity change is not smooth.
I manage this eg. with like here:
DoubleAnimation animate = new DoubleAnimation();
animate.From = 1.0;
animate.To = 0.5;
animate.Duration = new Duration(TimeSpan.FromSeconds(0));
this.BeginAnimation(Window.OpacityProperty, animate); // main window
Window1 win = new Window1(); // new window to get focus
win.ShowDialog();
Tell me please, if you know, does this effect works on GPU by default? If not, can I manage this somehow?
The maximization issue sounds like the computer might have performance issues, and the Duration issue exists because you set it to 0, a zero second animation is instant, of course it is not smooth.

Fix display garbage left by WPF dialog window?

In my WPF app, I have WPF windows that can open other WPF dialog windows, which I do as follows:
PickForEveryone PickForEveryoneWindow = new PickForEveryone(sSelRecipe, selMRM.sDay, selMRM.MealTypeID);
PickForEveryoneWindow.Owner = this;
PickForEveryoneWindow.ShowDialog();
Where PickForEveryone is defined as:
public partial class PickForEveryone : Window
and
<Window x:Class="PFWb0.PickForEveryone"
xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
xmlns:dg="http://schemas.microsoft.com/wpf/2008/toolkit"
ShowInTaskbar="False"
Title="Pick Recipe For All" Height="536" Width="441"
WindowStartupLocation="CenterOwner">
And contains a Grid with a DataGrid and a few buttons and check boxes.
Which works fine on my development computers. However, my client keeps seeing the dialog windows leave part of their display as visual litter on top of the parent window when the dialog window closes. That is, only some of the window undraws when ShowDialog() returns.
I tried adding this.InvalidateVisual(); below the above code, but it didn't solve the problem.
I also saw a suggestion here (for another kind of WPF display problem) to call OnRender() to force a redraw, but OnRender requires a parameter of type DrawingContext, which I don't know how to get.
So, I am asking if anyone knows how to either fix the display problem in the first place, or how to recover from it by getting WPF to redraw a window.
Update: As seen in comments to suggested answers below, I still have no solution that works on my client's computers, and my workaround (of having the windows dodge each other) is no longer enough. The only thing that works is to minimize and maximize the polluted underlying window.
I had a similar problem on a specific computer with an ATOM N270 processor.
The problem seamed to be linked to the graphic hardware acceleration.
To deactivate the accelaration, just add this to the registery (this will deactivate hardware acceleration for all WPF applications) :
HKEY_CURRENT_USER\SOFTWARE\Microsoft\Avalon.Graphics\DisableHWAcceleration
I had to create the Avalon.Graphics folder.
DisableHWAcceleration is a DWORD that has to be set to 1.
This had solve my problem, if I reactivate the acceleration, the problem come back.
Hope this helps.
References :
Guidelines for troubleshooting graphic issues in WPF applications : http://msdn.microsoft.com/en-us/library/aa970912(v=vs.90).aspx
Graphics Rendering Registry Settings : http://support.microsoft.com/kb/963021
This ugly code works for me:
void RefreshWindow()
{
switch (WindowState)
{
case WindowState.Maximized:
{
double oldWidth = Width;
Width = System.Windows.SystemParameters.PrimaryScreenWidth - 1;
WindowState = System.Windows.WindowState.Normal;
WindowState = System.Windows.WindowState.Maximized;
Width = oldWidth;
}
break;
case WindowState.Normal:
if (Width > 1)
{
Width -= 1;
Width += 1;
}
else
{
Width += 1;
Width -= 1;
}
break;
case WindowState.Minimized:
default:
// no action necessary
break;
}
}
So I have been looking for an answer to this on the MS forums, and apparently, variations of this question have been a asked for a few years now.
Sometimes, they say, the problem has to do with video drivers, of all things, although in my case, my client has recently updated his video drivers.
My impression is that Microsoft thought they designed WPF so that a developer should never need to do such a thing as force a redraw of the display, so they make no way to do so by design. Of course, when things go wrong for whatever reason, this means there is no straightforward way to do so. And the ways that seem like they might do so (such as InvalidateVisual()), don't.
But I did find one hack that does work. Well, two. The ugly one is to tell the window to minimize and return to normal. But that results in a visual animation of it doing so, which is not ideal. In my case, it also made it hide behind other open windows, requiring me to make it go topmost. But is does solve the problem, in a jarring way.
Code after ShowDialog:
this.WindowState = WindowState.Minimized;
this.WindowState = WindowState.Normal;
this.Topmost = true;
The better hack, looks a bit like this:
Code outside:
public delegate void NoArgDelegate();
Code after ShowDialog:
this.Dispatcher.Invoke(
System.Windows.Threading.DispatcherPriority.Loaded,
(NoArgDelegate)delegate {}
);
Presto ala kazzam!
This solution works, but it is not very pretty (easy to see that dialog is minimized and then set to normal).
this.WindowState = WindowState.Minimized;
this.WindowState = WindowState.Normal;
this.Topmost = true;
So far nothing I have tried actually works on my client's computer.
I have a new fix (workaround hack) attempt in for client testing, which involves moving the window away, and trying to make it actually take effect by launching an empty window just before I close the dialog window. Sigh...

SL 4 -- Force redraw of visual tree

Our application has a number of objects on a canvas; the canvas is contained in a scroll viewer. We also have a slider control and some buttons, always centered at the top of the window.
I am trying to print the application by capturing a bitmap of the app, but without any 'decorations' -- slider, buttons, or scroll bars.
_scrollViewer.HorizontalScrollBarVisibility = ScrollBarVisibility.Hidden;
_scrollViewer.VerticalScrollBarVisibility = ScrollBarVisibility.Hidden;
var s = xSlider;
s.Visibility = Visibility.Collapsed;
var b = xPlusButton;
b.Visibility = Visibility.Collapsed;
b = xMinusButton;
b.Visibility = Visibility.Collapsed;
b = xButton;
b.Visibility = Visibility.Collapsed;
The slider and buttons are hidden, as expected, but the scrollbars are not.
I suspect the application needs to redraw the layout in order to hide the scrollbars. Is there a way to make that happen? This is made more complicated by the fact that the print operation in SL 4 must be initiated by a UI gesture; there is no way (AFAIK) to initiate programatically, so this redraw must happen in one of the PrintDocument event handlers.
Thanks for any suggestions....
Try following,
canvas.InvalidateMeasure();
canvas.InvalidateArrange();
You can alternatively use WritableBitmap to capture runtime image and send image to print document if in case print document is ignoring render transform.
Also if you are using WritableBitmap to capture the element then you should give RenderTransform as second argument. Can you post your code to capture screen?
In addition to the InvalidateMeasure and InvalidateArrange methods, as suggested by Akash, you can try the UpdateLayout method.
The two invalidate methods will mark the control's measure or arrange as needing to be executed again, but won't necessarily do it immediately. The UpdateLayout will force it to execute some updates immediately.
It's a bit of a black box, so you may need to invalidate then call UpdateLayout. Sometimes you may just need to call UpdateLayout.

WPF Window with Style=None cover taskbar when Maximised after app initialization

I want to achieve the same effect as Windows Media Player or Browser based Flash players which take up the ENTIRE (not even the taskbar is visible) real estate when maximized.
This works fine if the WindowState is set to Maximized and the WindowStyle is set to None in XAML so the app is started in that state. Problem is I want to start the app in a bordered window and when the user chooses, maximize as specified above. In the StateChanged handler I check for Maximized state and if this is the case I set the WindowStyle to None. This has the effect of maximizing the window but NOT covering the taskbar. The following code will make this work as I want but its a hack and I'd like to clean it up:
if (WindowState == WindowState.Maximized)
{
m_videoWindow.Maximize();
WindowStyle = WindowStyle.None;
//the following makes this work but I would like to clean it up
Hide();
Show();
}
EDIT This (from 2006 when still in CTP) mentions the problem and someone from MS states they hope to improve full screen support in the next version, have these improvements been made?
This article explains it all: Maximizing window (with WindowStyle=None) considering Taskbar.
Also worth checking out: Custom Window Chrome in WPF.
Edit: Now new, is the WPF Shell Integration Library that allows complete restyle of the window chrome without the headaches of reimplementing move, resizing, etc.
Edit 2015: Shell Integration Library is now integrated in WPF and MS retired the code
I found I could maximize to full screen (covering the taskbar) by setting the properties when creating the window (in xaml), but was not able to switch back and forth after creation. After some experimenting, I found the order the properties are set seems to matter:
public bool IsFullscreen
{
get
{
return WindowState == System.Windows.WindowState.Maximized
&& ResizeMode == System.Windows.ResizeMode.NoResize
&& WindowStyle== System.Windows.WindowStyle.None;
}
set
{
if ( value )
{
ResizeMode = System.Windows.ResizeMode.NoResize;
WindowStyle = System.Windows.WindowStyle.None;
WindowState = System.Windows.WindowState.Maximized;
}
else
{
ResizeMode = System.Windows.ResizeMode.CanResize;
WindowStyle = System.Windows.WindowStyle.SingleBorderWindow;
WindowState = System.Windows.WindowState.Normal;
}
}
}
Note that WindowState comes last in the setter.
To get this to properly work in my WPF/.NET 4.0 application I am calling this function whenever I enter or exit full screen mode:
private static void RefreshWindowVisibility(Window window)
{
if (window.OriginalWindowState == WindowState.Maximized)
{
window.Hide();
window.Show();
window.BringIntoView();
}
}
There is a flicker associated with this method, but it seems the same flicker exists when going to full screen mode on Chrome. Internet Explorer seems to take a different approach.
I don't know if this is ok for you, but you can resize the window to have the same size than the working area (that is, in most cases, all the screen except the taskbar) and locate it at 0,0 (top-left corner):
Width = System.Windows.Forms.Screen.PrimaryScreen.WorkingArea.Width;
Height = System.Windows.Forms.Screen.PrimaryScreen.WorkingArea.Height;
Left = 0;
Top = 0;
The exact definition for the WorkingArea property (from MSDN) is:
Gets the working area of the display. The working area is the desktop area of the display, excluding taskbars, docked windows, and docked tool bars.
Hope it helps

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