How to disable focus in WPF? - wpf

I created an application but I have a problem with the focus. How can I disable the focus of another main form when the form loads?

WPF forms have a ShowActivated property. Set this to false and the form won't get the focus.
You may also override the OnActivated method :
protected override void OnActivated(EventArgs e)
{
base.OnActivated(e);
//Set the window style to noactivate.
WindowInteropHelper helper = new WindowInteropHelper(this);
SetWindowLong(helper.Handle, GWL_EXSTYLE,
GetWindowLong(helper.Handle, GWL_EXSTYLE) | WS_EX_NOACTIVATE);
}
private const int GWL_EXSTYLE = -20;
private const int WS_EX_NOACTIVATE = 0x08000000;
[DllImport("user32.dll")]
public static extern IntPtr SetWindowLong(IntPtr hWnd, int nIndex, int dwNewLong);
[DllImport("user32.dll")]
public static extern int GetWindowLong(IntPtr hWnd, int nIndex);

Related

Standalone WPF Form in VSTO Excel Addin Won't Keep Focus

I am creating a VSTO Plugin for Excel and my first attempt works, but I am not happy with the design. As standard VSTO only handles Windows Forms. I am getting in to WPF now and have found the options for layout and animations make for a much better user experience.
I have now found that I can add a WPF Project to the VSTO Solution and call the forms that way... Excellent!
The problem is when I load a form I do this:
Dim NewForm as New NewForm
NewForm.Show()
This works fine, and the form opens, however if I try to type in a textbox, the form drops behind excel and the text goes in to the active cell in Excel.
If I do:
Dim NewForm as New NewForm
NewForm.ShowDialog()
it works fine. Unfortunately I cannot have the form being modal for my application. How can I get around this?
I use the following class:
https://dl.dropboxusercontent.com/u/62538279/Help/OfficeDialog.cs
You'll notice that the ShowDialog() method is replaced
The class also makes the dialog look like a Word VBA form (something my clients often want)
My dialog.xaml.cs class looks like (and the xaml matches):
public partial class myDialog : OfficeDialog
-- Edit --
Here's the source code. I've been having trouble with it. It occasionally slips behind the application (very rarely)
http://stackoverflow.com/questions/40374059/why-does-my-modal-wpf-dialog-slip-behind-ms-word/40401198#40401198
using System;
using System.Diagnostics;
using System.Runtime.InteropServices;
using System.Windows;
using System.Windows.Interop;
public class OfficeDialog : Window
{
[DllImport("user32.dll")]
static extern int GetWindowLong(IntPtr hwnd, int index);
[DllImport("user32.dll")]
static extern int SetWindowLong(IntPtr hwnd, int index, int newStyle);
[DllImport("user32.dll")]
static extern bool SetWindowPos(IntPtr hwnd, IntPtr hwndInsertAfter, int x, int y, int width, int height, uint flags);
[DllImport("user32.dll")]
static extern IntPtr SendMessage(IntPtr hwnd, uint msg, IntPtr wParam, IntPtr lParam);
const int GWL_EXSTYLE = -20;
const int WS_EX_DLGMODALFRAME = 0x0001;
const int SWP_NOSIZE = 0x0001;
const int SWP_NOMOVE = 0x0002;
const int SWP_NOZORDER = 0x0004;
const int SWP_FRAMECHANGED = 0x0020;
const uint WM_SETICON = 0x0080;
const int ICON_SMALL = 0;
const int ICON_BIG = 1;
/// <summary>
/// Sometimes get System.ComponentModel.Win32Exception: Invalid window handle
/// I'm pretty sure that this is because Word is shit at handling windows and has an internal memory leak
/// http://stackoverflow.com/questions/222649/winforms-issue-error-creating-window-handle
/// I'm not sure why this error isn't trapped and logged by the try catch below. Somehow it bubbles up to the calling routine..
/// </summary>
public OfficeDialog()
{
this.ShowInTaskbar = false;
//this.Topmost = true;
//Uri uri = new Uri("PresentationFramework.Aero;V3.0.0.0;31bf3856ad364e35;component\\themes/aero.normalcolor.xaml", UriKind.Relative);
//Uri uri = new Uri("PresentationFramework.Classic;V3.0.0.0;31bf3856ad364e35;component\\themes/classic.xaml", UriKind.Relative);
//Resources.MergedDictionaries.Add(Application.LoadComponent(uri) as ResourceDictionary);
//var helper = new WindowInteropHelper(this);
//using (Process currentProcess = Process.GetCurrentProcess())
// helper.Owner = currentProcess.MainWindowHandle;
}
public new void ShowDialog()
{
try
{
var helper = new WindowInteropHelper(this);
using (Process currentProcess = Process.GetCurrentProcess())
helper.Owner = currentProcess.MainWindowHandle;
base.ShowDialog();
}
catch (System.ComponentModel.Win32Exception ex)
{
Message.LogWarning(ex);
//this.Topmost = true;
var helper = new WindowInteropHelper(this);
using (Process currentProcess = Process.GetCurrentProcess())
helper.Owner = currentProcess.MainWindowHandle;
base.ShowDialog();
}
}
protected override void OnSourceInitialized(EventArgs e)
{
base.OnSourceInitialized(e);
RemoveIcon(this);
HideMinimizeAndMaximizeButtons(this);
//using (Process currentProcess = Process.GetCurrentProcess())
// SetCentering(this, currentProcess.MainWindowHandle);
}
public static void HideMinimizeAndMaximizeButtons(Window window)
{
const int GWL_STYLE = -16;
IntPtr hwnd = new WindowInteropHelper(window).Handle;
long value = GetWindowLong(hwnd, GWL_STYLE);
SetWindowLong(hwnd, GWL_STYLE, (int)(value & -131073 & -65537));
}
public static void RemoveIcon(Window w)
{
// Get this window's handle
IntPtr hwnd = new WindowInteropHelper(w).Handle;
// Change the extended window style to not show a window icon
int extendedStyle = OfficeDialog.GetWindowLong(hwnd, GWL_EXSTYLE);
OfficeDialog.SetWindowLong(hwnd, GWL_EXSTYLE, extendedStyle | WS_EX_DLGMODALFRAME);
// reset the icon, both calls important
OfficeDialog.SendMessage(hwnd, WM_SETICON, (IntPtr)ICON_SMALL, IntPtr.Zero);
OfficeDialog.SendMessage(hwnd, WM_SETICON, (IntPtr)ICON_BIG, IntPtr.Zero);
// Update the window's non-client area to reflect the changes
OfficeDialog.SetWindowPos(hwnd, IntPtr.Zero, 0, 0, 0, 0, SWP_NOMOVE | SWP_NOSIZE | SWP_NOZORDER | SWP_FRAMECHANGED);
}
static void SetCentering(Window win, IntPtr ownerHandle)
{
bool isWindow = IsWindow(ownerHandle);
if (!isWindow) //Don't try and centre the window if the ownerHandle is invalid. To resolve issue with invalid window handle error
{
//Message.LogInfo(string.Format("ownerHandle IsWindow: {0}", isWindow));
return;
}
//Show in center of owner if win form.
if (ownerHandle.ToInt32() != 0)
{
var helper = new WindowInteropHelper(win);
helper.Owner = ownerHandle;
win.WindowStartupLocation = WindowStartupLocation.CenterOwner;
}
else
win.WindowStartupLocation = WindowStartupLocation.CenterOwner;
}
[DllImport("user32.dll")]
[return: MarshalAs(UnmanagedType.Bool)]
static extern bool IsWindow(IntPtr hWnd);
}

What is the equal of HelpButton In Wpf Application Window? [duplicate]

How can add this button to the title bar in WPF, by it being so used in a lot of applications I thought it would be built in or something, but looks like it isn't. Anyway let me know if you know anything about this.
Thanks.
Edit:
Isn't there anything equivalent to this?
Basically, to have the ? icon in win forms, all you need to do is this:
public Form1()
{
InitializeComponent();
this.HelpButton = true;
this.MaximizeBox = false;
this.MinimizeBox = false;
}
Doesn't WPF have anything like that?
It's simple, just inset this code into your Window class.
This code uses interop to remove the WS_MINIMIZEBOX and WS_MAXIMIZEBOX styles and add the WS_EX_CONTEXTHELP extended style (the question mark will only show up if you remove the minimize and maximize buttons).
EDIT: added click detection on the help button, this is done by hooking into the WndProc using HwndSource.AddHook and listening for a WM_SYSCOMMAND message with wParam of SC_CONTEXTHELP.
When a click is detected this code will show a message box, changing this into an event, routed event or even a command (for MVVM apps) is left as an exercise for the reader.
private const uint WS_EX_CONTEXTHELP = 0x00000400;
private const uint WS_MINIMIZEBOX = 0x00020000;
private const uint WS_MAXIMIZEBOX = 0x00010000;
private const int GWL_STYLE = -16;
private const int GWL_EXSTYLE = -20;
private const int SWP_NOSIZE = 0x0001;
private const int SWP_NOMOVE = 0x0002;
private const int SWP_NOZORDER = 0x0004;
private const int SWP_FRAMECHANGED = 0x0020;
private const int WM_SYSCOMMAND = 0x0112;
private const int SC_CONTEXTHELP = 0xF180;
[DllImport("user32.dll")]
private static extern uint GetWindowLong(IntPtr hwnd, int index);
[DllImport("user32.dll")]
private static extern int SetWindowLong(IntPtr hwnd, int index, uint newStyle);
[DllImport("user32.dll")]
private static extern bool SetWindowPos(IntPtr hwnd, IntPtr hwndInsertAfter, int x, int y, int width, int height, uint flags);
protected override void OnSourceInitialized(EventArgs e)
{
base.OnSourceInitialized(e);
IntPtr hwnd = new System.Windows.Interop.WindowInteropHelper(this).Handle;
uint styles = GetWindowLong(hwnd, GWL_STYLE);
styles &= 0xFFFFFFFF ^ (WS_MINIMIZEBOX | WS_MAXIMIZEBOX);
SetWindowLong(hwnd, GWL_STYLE, styles);
styles = GetWindowLong(hwnd, GWL_EXSTYLE);
styles |= WS_EX_CONTEXTHELP;
SetWindowLong(hwnd, GWL_EXSTYLE, styles);
SetWindowPos(hwnd, IntPtr.Zero, 0, 0, 0, 0, SWP_NOMOVE | SWP_NOSIZE | SWP_NOZORDER | SWP_FRAMECHANGED);
((HwndSource)PresentationSource.FromVisual(this)).AddHook(HelpHook);
}
private IntPtr HelpHook(IntPtr hwnd,
int msg,
IntPtr wParam,
IntPtr lParam,
ref bool handled)
{
if (msg == WM_SYSCOMMAND &&
((int)wParam & 0xFFF0) == SC_CONTEXTHELP)
{
MessageBox.Show("help");
handled = true;
}
return IntPtr.Zero;
}
No help buttons come out of the box with WPF. Should'nt be a push to roll your own however.

How can I prevent focus stealing, but still get focus when returning to my app using Alt+Tab?

Following MS guidelines, my WPF application's App constructor includes the following code for proper focus behavior:
HwndSource.DefaultAcquireHwndFocusInMenuMode = false;
Keyboard.DefaultRestoreFocusMode = RestoreFocusMode.None;
As explained in this article, these settings prevent focus stealing.
However, setting DefaultRestoreFocusMode to None has a bad side effect. When using Alt+Tab to leave a WPF application and then return to it, the WPF application doesn't get focus. However, if I don't set DefaultRestoreFocusMode to none, it does get focus as expected. Is there a way to prevent focus stealing but have focus still set when returning to a WPF application via Alt+Tab?
-Craig
I prevent my wpf window from getting focus by doing the below and i can still activate it by using ALT-TAB or clicking on it's taskbar item.
Here you change the window styles on your window so that it has no activate.
var yourWindow = new YourWindowType();
//set the windowstyle to noactivate so the window doesn't get focus
yourWindow.SourceInitialized += (s, e) =>
{
var interopHelper = new WindowInteropHelper(yourWindow);
int exStyle = User32.GetWindowLong(interopHelper.Handle, (int)WindowLongFlags.GWL_EXSTYLE);
User32.SetWindowLong(interopHelper.Handle, (int)WindowLongFlags.GWL_EXSTYLE, exStyle | (int)WindowStylesEx.WS_EX_NOACTIVATE);
//If you have trouble typing into your form's textboxes then do this
ElementHost.EnableModelessKeyboardInterop(yourWindow);
};
This is something i added as an extra precaution, plus it lets you drag your window around if it is borderless:
private IntPtr WndProc(IntPtr hwnd, int msg, IntPtr wParam, IntPtr lParam, ref bool handled)
{
switch (msg)
{
//don't activate the window when you click on it.
case WindowMessage.WM_MOUSEACTIVATE:
handled = true;
return (IntPtr)MouseActivate.MA_NOACTIVATE;
//For Borderless Windows: occurs while dragging. it reports new position before it has been finalized.
//otherwise you wont see the window moving while you're dragging it
case WindowMessage.WM_MOVING:
RECT rect = (RECT)Marshal.PtrToStructure(lParam, typeof(RECT));
User32.SetWindowPos(new WindowInteropHelper(this).Handle, Hwnd.HWND_TOPMOST,
rect.Left, rect.Top, rect.Width, rect.Height,
SetWindowPosFlags.SWP_NOACTIVATE | SetWindowPosFlags.SWP_NOSIZE);
break;
}
return IntPtr.Zero;
}
These add a hook so that WndProc is actually called in WPF:
private void Window_Loaded(object sender, RoutedEventArgs e)
{
HwndSource source = HwndSource.FromHwnd(new WindowInteropHelper(this).Handle);
if (source == null) return;
source.AddHook(WndProc);
}
private void Window_Closing(object sender, System.ComponentModel.CancelEventArgs e)
{
HwndSource source = HwndSource.FromHwnd(new WindowInteropHelper(this).Handle);
if (source == null) return;
source.RemoveHook(WndProc);
}
Just an FYI.. this still works even though you don't get focus:
private void WpfPillForm_MouseLeftButtonDown(object sender, MouseButtonEventArgs e)
{
this.DragMove();
}
Here's the Win32 API declarations so you don't have to look them up:
[StructLayout(LayoutKind.Sequential)]
public struct WINDOWPOS
{
public IntPtr hwnd;
public IntPtr hwndInsertAfter;
public int x;
public int y;
public int cx;
public int cy;
public int flags;
}
[StructLayout(LayoutKind.Sequential)]
struct RECT
{
public int left, top, right, bottom;
}
public static class MouseActivate
{
public const int MA_ACTIVATE = 1;
public const int MA_ACTIVATEANDEAT = 2;
public const int MA_NOACTIVATE = 3;
public const int MA_NOACTIVATEANDEAT = 4;
}
public enum WindowLongFlags : int
{
GWL_EXSTYLE = -20,
GWLP_HINSTANCE = -6,
GWLP_HWNDPARENT = -8,
GWL_ID = -12,
GWL_STYLE = -16,
GWL_USERDATA = -21,
GWL_WNDPROC = -4,
DWLP_USER = 0x8,
DWLP_MSGRESULT = 0x0,
DWLP_DLGPROC = 0x4
}
public const int WM_MOVING = 0x0216;
public const uint WS_EX_NOACTIVATE = 0x08000000,
[DllImport("user32.dll")]
[return: MarshalAs(UnmanagedType.Bool)]
public static extern bool SetWindowPos(IntPtr hWnd, IntPtr hWndInsertAfter, int X, int Y, int cx, int cy, SetWindowPosFlags uFlags);
[DllImport("user32.dll", CharSet = CharSet.Auto, SetLastError = true)]
public static extern int SetWindowLong(IntPtr hWnd, int nIndex, int dwNewLong);
[DllImport("user32.dll", CharSet = CharSet.Auto, SetLastError = true)]
public static extern int GetWindowLong(IntPtr hwnd, int index);

Removing Icon from a WPF window

I am able to remove the window icon from WPF window using WinApi's, however I get the icon again in the application window when I run just the executable of the WPF project.
How do I remove the icon?
From WPFTutorial:
How to remove the icon of a WPF window
Unfortunately WPF does not provide any function to remove the icon of a window. One solution could be setting the icon to a transparent icon. But this way the extra space between the window border and title remains.
The better approach is to use a function provided by the Win32 API to remove the icon.
public partial class Window1 : Window
{
public Window1()
{
InitializeComponent();
}
protected override void OnSourceInitialized(EventArgs e)
{
IconHelper.RemoveIcon(this);
}
}
A helper class used to remove the icon.
public static class IconHelper
{
[DllImport("user32.dll")]
static extern int GetWindowLong(IntPtr hwnd, int index);
[DllImport("user32.dll")]
static extern int SetWindowLong(IntPtr hwnd, int index, int newStyle);
[DllImport("user32.dll")]
static extern bool SetWindowPos(IntPtr hwnd, IntPtr hwndInsertAfter,
int x, int y, int width, int height, uint flags);
[DllImport("user32.dll")]
static extern IntPtr SendMessage(IntPtr hwnd, uint msg,
IntPtr wParam, IntPtr lParam);
const int GWL_EXSTYLE = -20;
const int WS_EX_DLGMODALFRAME = 0x0001;
const int SWP_NOSIZE = 0x0001;
const int SWP_NOMOVE = 0x0002;
const int SWP_NOZORDER = 0x0004;
const int SWP_FRAMECHANGED = 0x0020;
const uint WM_SETICON = 0x0080;
public static void RemoveIcon(Window window)
{
// Get this window's handle
IntPtr hwnd = new WindowInteropHelper(window).Handle;
// Change the extended window style to not show a window icon
int extendedStyle = GetWindowLong(hwnd, GWL_EXSTYLE);
SetWindowLong(hwnd, GWL_EXSTYLE, extendedStyle | WS_EX_DLGMODALFRAME);
// Update the window's non-client area to reflect the changes
SetWindowPos(hwnd, IntPtr.Zero, 0, 0, 0, 0, SWP_NOMOVE |
SWP_NOSIZE | SWP_NOZORDER | SWP_FRAMECHANGED);
}
}
Just add this WindowStyle="ToolWindow" to your window properties.
I have modified the sample from 'LnDCobra' so it can be used as an attached property (as 'Thomas' suggested:
<Window
...
xmlns:i="clr-namespace:namespace-to-WindowEx"
i:WindowEx.ShowIcon = "false"
...
>
Implementation of WindowEx:
public class WindowEx
{
private const int GwlExstyle = -20;
private const int SwpFramechanged = 0x0020;
private const int SwpNomove = 0x0002;
private const int SwpNosize = 0x0001;
private const int SwpNozorder = 0x0004;
private const int WsExDlgmodalframe = 0x0001;
public static readonly DependencyProperty ShowIconProperty =
DependencyProperty.RegisterAttached(
"ShowIcon",
typeof (bool),
typeof (WindowEx),
new FrameworkPropertyMetadata(true, new PropertyChangedCallback((d, e) => RemoveIcon((Window) d))));
public static Boolean GetShowIcon(UIElement element)
{
return (Boolean) element.GetValue(ShowIconProperty);
}
public static void RemoveIcon(Window window)
{
window.SourceInitialized += delegate {
// Get this window's handle
var hwnd = new WindowInteropHelper(window).Handle;
// Change the extended window style to not show a window icon
int extendedStyle = GetWindowLong(hwnd, GwlExstyle);
SetWindowLong(hwnd, GwlExstyle, extendedStyle | WsExDlgmodalframe);
// Update the window's non-client area to reflect the changes
SetWindowPos(hwnd, IntPtr.Zero, 0, 0, 0, 0, SwpNomove |
SwpNosize | SwpNozorder | SwpFramechanged);
};
}
public static void SetShowIcon(UIElement element, Boolean value)
{
element.SetValue(ShowIconProperty, value);
}
[DllImport("user32.dll")]
private static extern int GetWindowLong(IntPtr hwnd, int index);
[DllImport("user32.dll")]
private static extern IntPtr SendMessage(IntPtr hwnd, uint msg,
IntPtr wParam, IntPtr lParam);
[DllImport("user32.dll")]
private static extern int SetWindowLong(IntPtr hwnd, int index, int newStyle);
[DllImport("user32.dll")]
private static extern bool SetWindowPos(IntPtr hwnd, IntPtr hwndInsertAfter,
int x, int y, int width, int height, uint flags);
}
}
Here a simple and pure XAML solution:
<Window x:Class="...">
<Window.Icon>
<DrawingImage />
</Window.Icon>
...
</Window>
I just use very small transparent image as an icon (1x1 px) for WPF window.
Create a transparent 1 by 1 icon and replace it with a standard one
Icon = BitmapSource.Create(1, 1, 0, 0, PixelFormats.Bgra32, null, new byte[4], 4);

Help "?" button

How can add this button to the title bar in WPF, by it being so used in a lot of applications I thought it would be built in or something, but looks like it isn't. Anyway let me know if you know anything about this.
Thanks.
Edit:
Isn't there anything equivalent to this?
Basically, to have the ? icon in win forms, all you need to do is this:
public Form1()
{
InitializeComponent();
this.HelpButton = true;
this.MaximizeBox = false;
this.MinimizeBox = false;
}
Doesn't WPF have anything like that?
It's simple, just inset this code into your Window class.
This code uses interop to remove the WS_MINIMIZEBOX and WS_MAXIMIZEBOX styles and add the WS_EX_CONTEXTHELP extended style (the question mark will only show up if you remove the minimize and maximize buttons).
EDIT: added click detection on the help button, this is done by hooking into the WndProc using HwndSource.AddHook and listening for a WM_SYSCOMMAND message with wParam of SC_CONTEXTHELP.
When a click is detected this code will show a message box, changing this into an event, routed event or even a command (for MVVM apps) is left as an exercise for the reader.
private const uint WS_EX_CONTEXTHELP = 0x00000400;
private const uint WS_MINIMIZEBOX = 0x00020000;
private const uint WS_MAXIMIZEBOX = 0x00010000;
private const int GWL_STYLE = -16;
private const int GWL_EXSTYLE = -20;
private const int SWP_NOSIZE = 0x0001;
private const int SWP_NOMOVE = 0x0002;
private const int SWP_NOZORDER = 0x0004;
private const int SWP_FRAMECHANGED = 0x0020;
private const int WM_SYSCOMMAND = 0x0112;
private const int SC_CONTEXTHELP = 0xF180;
[DllImport("user32.dll")]
private static extern uint GetWindowLong(IntPtr hwnd, int index);
[DllImport("user32.dll")]
private static extern int SetWindowLong(IntPtr hwnd, int index, uint newStyle);
[DllImport("user32.dll")]
private static extern bool SetWindowPos(IntPtr hwnd, IntPtr hwndInsertAfter, int x, int y, int width, int height, uint flags);
protected override void OnSourceInitialized(EventArgs e)
{
base.OnSourceInitialized(e);
IntPtr hwnd = new System.Windows.Interop.WindowInteropHelper(this).Handle;
uint styles = GetWindowLong(hwnd, GWL_STYLE);
styles &= 0xFFFFFFFF ^ (WS_MINIMIZEBOX | WS_MAXIMIZEBOX);
SetWindowLong(hwnd, GWL_STYLE, styles);
styles = GetWindowLong(hwnd, GWL_EXSTYLE);
styles |= WS_EX_CONTEXTHELP;
SetWindowLong(hwnd, GWL_EXSTYLE, styles);
SetWindowPos(hwnd, IntPtr.Zero, 0, 0, 0, 0, SWP_NOMOVE | SWP_NOSIZE | SWP_NOZORDER | SWP_FRAMECHANGED);
((HwndSource)PresentationSource.FromVisual(this)).AddHook(HelpHook);
}
private IntPtr HelpHook(IntPtr hwnd,
int msg,
IntPtr wParam,
IntPtr lParam,
ref bool handled)
{
if (msg == WM_SYSCOMMAND &&
((int)wParam & 0xFFF0) == SC_CONTEXTHELP)
{
MessageBox.Show("help");
handled = true;
}
return IntPtr.Zero;
}
No help buttons come out of the box with WPF. Should'nt be a push to roll your own however.

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