I am trying to hook mouse events to combobox. sample code is here.
But it is working fine if keep project properties [Prefer 32 bit TRUE] but GetComboBoxInfo API is failing with error code 87 if i keep Prefer 32 bit FALSE.
Here is place where code is failing:
public static IntPtr GetChildListWindowHandle(Control ctrl)
{
Win32.ComboBoxInfo comboBoxInfo = new Win32.ComboBoxInfo();
comboBoxInfo.cbSize = (uint)Marshal.SizeOf(comboBoxInfo);
Win32.GetComboBoxInfo(ctrl.Handle, ref comboBoxInfo);
uint error = GetLastError() ;
if (true == Win32.GetComboBoxInfo(ctrl.Handle, ref comboBoxInfo))
{
return comboBoxInfo.hwndList;
}
return IntPtr.Zero;
}
[StructLayout(LayoutKind.Sequential)]
public struct ComboBoxInfo
{
public uint cbSize;
public RECT rcItem;
public RECT rcButton;
public IntPtr stateButton;
public IntPtr hwndCombo;
public IntPtr hwndEdit;
public IntPtr hwndList;
}
[DllImport("user32.dll")]
public static extern bool GetComboBoxInfo(IntPtr hwndCombo, ref ComboBoxInfo info);
Related
I have a SaveFileDialog in my WPF Project.
If the SaveFileDialog is closed via the red 'x' in the corner, I want the dialog to close and the user to be returned to the main application.
However, if the SaveFileDialog is 'canceled', I want the entire application to close.
The only issue I am having is knowing if the user has pressed the red x or the cancel button. They both evaluate to false in the code below.
SaveFileDialog saveFileDialog = new SaveFileDialog();
saveFileDialog.Filter = "Text file (*.txt)|*.txt";
var dlg = saveFileDialog.ShowDialog();
if (dlg == true)
{
//When the user presses save
File.WriteAllLines(saveFileDialog.FileName, rowList);
ExitApp();
}
else if (dlg == false)
{
//This occurs when red x or cancel is pressed.
}
Is there any way to distinguish between the two in WPF?
The answer is short and simple:
"no"
See Microsoft documentation here
It is not so simple, but you can do it by using hooks and the SetWindowsHookEx method.
First of all we need a class for registering and unregistering our hook:
public class WinHooker
{
[DllImport("user32.dll", CharSet = CharSet.Auto, CallingConvention = CallingConvention.StdCall, SetLastError = true)]
private static extern int SetWindowsHookEx(int idHook, HookProc lpfn, IntPtr hMod, int dwThreadId);
[DllImport("user32.dll", CharSet = CharSet.Auto, CallingConvention = CallingConvention.StdCall)]
private static extern int CallNextHookEx(int idHook, int nCode, int wParam, IntPtr lParam);
[DllImport("user32.dll", CharSet = CharSet.Auto, CallingConvention = CallingConvention.StdCall, SetLastError = true)]
private static extern int UnhookWindowsHookEx(int idHook);
private delegate int HookProc(int nCode, int wParam, IntPtr lParam);
private HookProc hookDelegate;
private int hookHandle;
private bool wasClosedButtonPressed;
private static WinHooker instance;
private WinHooker()
{
}
public static WinHooker Instance
{
get
{
if (instance == null)
{
instance = new WinHooker();
}
return instance;
}
}
public bool WasClosedButtonPressed
{
get
{
return wasClosedButtonPressed;
}
}
public void Register()
{
wasClosedButtonPressed = false;
hookDelegate = this.HookProcHandler;
hookHandle = SetWindowsHookEx(5,
hookDelegate,
IntPtr.Zero,
AppDomain.GetCurrentThreadId());
}
public void Unregister()
{
UnhookWindowsHookEx(hookHandle);
hookHandle = 0;
hookDelegate = null;
}
private int HookProcHandler(int nCode, int wParam, IntPtr lParam)
{
if (nCode >= 0)
{
if (nCode == 8 && wParam == 0xF060)
{
wasClosedButtonPressed = true;
}
}
return CallNextHookEx(hookHandle, nCode, wParam, lParam);
}
}
As you can see I used 5 as the first parameter for the SetWindowsHookEx, since it correspond to the WH_CBT value (refer to the SetWindowsHookEx page). Moreover the values in the method HookProcHandler (i.e. nCode == 8 && wParam == 0xF060) can be retrived from here.
Now let's use our class in the code:
SaveFileDialog saveFileDialog = new SaveFileDialog();
WinHooker.Instance.Register();
saveFileDialog.ShowDialog();
WinHooker.Instance.Unregister();
if (WinHooker.Instance.WasClosedButtonPressed)
{
MessageBox.Show("Oh my God! What have you done??");
}
As you can understand WasClosedButtonPressed is set to true just if the user closes the dialog by clicking on the red 'x' in the corner. Otherwise it is false.
I hope it can help you.
I have a WPF app (written in C#) which has a Listview control which scrolls perfectly with the mouse wheel when the app is in focus.
However when the app is not in focus, even when the mouse pointer is over the app & list view area, the Listview does not scroll. I continue to see mousehover related effects on the app but no mousewheel event is received. This is inline with how most of the other apps work on my desktop however some of them (like Facebook messenger) support scrolling without focus which i would like to mimic in my WPF app.
I have searched MSDN forums and Stackoverflow and seen multiple solutions for Windows Forms however they were questions asked over 5 years ago and i was wondering if someone has managed to do it relatively easily on .net 4.5 and can point me to possible solutions.
---Edit---
I was able to progress to some extent on this thanks to this thread C# ListView mouse wheel scroll without focus
Here is how my the function that receives the mousewheel looks
private static IntPtr HookCallback(
int nCode, IntPtr wParam, IntPtr lParam)
{
if (nCode >= 0 &&
MouseMessages.WM_MOUSEWHEEL == (MouseMessages)wParam)
{
MSLLHOOKSTRUCT hookStruct = (MSLLHOOKSTRUCT)Marshal.PtrToStructure(lParam, typeof(MSLLHOOKSTRUCT));
Console.WriteLine(hookStruct.pt.x + ", " + hookStruct.pt.y);
Console.WriteLine((short)((hookStruct.mouseData)>>16));
MouseWheelEventArgs myArgs = new MouseWheelEventArgs(System.Windows.Input.Mouse.PrimaryDevice, (int)hookStruct.time, (short)((hookStruct.mouseData)>>16));
myMainFrame.SidePanelControl.ScrollTheListView(myArgs);
}
return CallNextHookEx(_hookID, nCode, wParam, lParam);
}
As you can see i am initializing a MouseWheelEventArgs instance and have the time, delta and the mouse device attributes.
How do i go about passing this mousewheel event to my listview scrollviewer?
Managed to get this working. Here is my class.
All one needs to do to use the class is
Initialize InterceptMouse passing it the app/listview/etc pointer
Start intercepting the mouse when the app is not in focus but the corresponding mouseenter event has occured.
As long as the event is mousewheel the scrollviewer of the listview will be sent the mouseWheel event.
Stop intercepting the mouse when the app gets activated or mouseleave is called.
using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Runtime.InteropServices;
using System.Windows.Interop;
using System.Windows.Forms;
using System.Windows;
using System.Windows.Controls;
using System.Windows.Media;
using System.Windows.Input;
using System.Diagnostics;
using System.Windows.Forms.Integration;
namespace myApp.HelperClasses
{
public class InterceptMouse
{
public static System.Windows.Controls.ListView myListview;
private static LowLevelMouseProc _proc = HookCallback;
private static IntPtr _hookID = IntPtr.Zero;
public InterceptMouse(System.Windows.Controls.ListView myListviewParam)
{
myListview = myListviewParam;
}
public static void StartIntercepting()
{
_hookID = SetHook(_proc);
}
public static void StopIntercepting()
{
UnhookWindowsHookEx(_hookID);
}
private static IntPtr SetHook(LowLevelMouseProc proc)
{
using (Process curProcess = Process.GetCurrentProcess())
using (ProcessModule curModule = curProcess.MainModule)
{
return SetWindowsHookEx(WH_MOUSE_LL, proc,
GetModuleHandle(curModule.ModuleName), 0);
}
}
private delegate IntPtr LowLevelMouseProc(int nCode, IntPtr wParam, IntPtr lParam);
private static IntPtr HookCallback(
int nCode, IntPtr wParam, IntPtr lParam)
{
if (nCode >= 0 &&
MouseMessages.WM_MOUSEWHEEL == (MouseMessages)wParam)
{
MSLLHOOKSTRUCT hookStruct = (MSLLHOOKSTRUCT)Marshal.PtrToStructure(lParam, typeof(MSLLHOOKSTRUCT));
//Console.WriteLine(hookStruct.pt.x + ", " + hookStruct.pt.y + "," + hookStruct.mouseData);
var delta = (short)((hookStruct.mouseData) >> 16);
var mouse = InputManager.Current.PrimaryMouseDevice;
var args = new MouseWheelEventArgs(mouse, Environment.TickCount, delta);
args.RoutedEvent = WindowsFormsHost.MouseWheelEvent;
Decorator border = VisualTreeHelper.GetChild(myListview, 0) as Decorator;
// Get scrollviewer
ScrollViewer scrollViewer = border.Child as ScrollViewer;
scrollViewer.RaiseEvent(args);
}
return CallNextHookEx(_hookID, nCode, wParam, lParam);
}
private const int WH_MOUSE_LL = 14;
private enum MouseMessages
{
WM_LBUTTONDOWN = 0x0201,
WM_LBUTTONUP = 0x0202,
WM_MOUSEMOVE = 0x0200,
WM_MOUSEWHEEL = 0x020A,
WM_RBUTTONDOWN = 0x0204,
WM_RBUTTONUP = 0x0205
}
[StructLayout(LayoutKind.Sequential)]
private struct POINT
{
public int x;
public int y;
}
[StructLayout(LayoutKind.Sequential)]
private struct MSLLHOOKSTRUCT
{
public POINT pt;
public uint mouseData;
public uint flags;
public uint time;
public IntPtr dwExtraInfo;
}
[DllImport("user32.dll", CharSet = CharSet.Auto, SetLastError = true)]
private static extern IntPtr SetWindowsHookEx(int idHook,
LowLevelMouseProc lpfn, IntPtr hMod, uint dwThreadId);
[DllImport("user32.dll", CharSet = CharSet.Auto, SetLastError = true)]
[return: MarshalAs(UnmanagedType.Bool)]
private static extern bool UnhookWindowsHookEx(IntPtr hhk);
[DllImport("user32.dll", CharSet = CharSet.Auto, SetLastError = true)]
private static extern IntPtr CallNextHookEx(IntPtr hhk, int nCode,
IntPtr wParam, IntPtr lParam);
[DllImport("kernel32.dll", CharSet = CharSet.Auto, SetLastError = true)]
private static extern IntPtr GetModuleHandle(string lpModuleName);
}
}
I have the following code, which adds an 'Always on Top' item to the system context menu as displayed on the window chrome. It works correctly, but I'd like it to display a check mark or similar to indicate if it's been toggled on/off.
Any idea how I can do this?
public RibbonShell()
{
InitializeComponent();
Loaded += (s,e) =>
{
// Get the Handle for the Forms System Menu
var systemMenuHandle = GetSystemMenu(Handle, false);
// Create our new System Menu items just before the Close menu item
InsertMenu(systemMenuHandle, 5, MfByposition | MfSeparator, 0, string.Empty); // <-- Add a menu seperator
InsertMenu(systemMenuHandle, 6, MfByposition, SettingsSysMenuId, "Always on Top");
// Attach our WindowCommandHandler handler to this Window
var source = HwndSource.FromHwnd(Handle);
source.AddHook(WindowCommandHandler);
};
}
#region Win32 API Stuff
// Define the Win32 API methods we are going to use
[DllImport("user32.dll")]
private static extern IntPtr GetSystemMenu(IntPtr hWnd, bool bRevert);
[DllImport("user32.dll")]
private static extern bool InsertMenu(IntPtr hMenu, Int32 wPosition, Int32 wFlags, Int32 wIDNewItem, string lpNewItem);
/// Define our Constants we will use
private const int WmSyscommand = 0x112;
private const int MfSeparator = 0x800;
private const int MfByposition = 0x400;
#endregion
// The constants we'll use to identify our custom system menu items
private const int SettingsSysMenuId = 1000;
/// <summary>
/// This is the Win32 Interop Handle for this Window
/// </summary>
public IntPtr Handle
{
get { return new WindowInteropHelper(this).Handle; }
}
private IntPtr WindowCommandHandler(IntPtr hwnd, int msg, IntPtr wParam, IntPtr lParam, ref bool handled)
{
// Check if a System Command has been executed
if (msg == WmSyscommand && wParam.ToInt32() == SettingsSysMenuId)
{
Topmost = !Topmost;
handled = true;
}
return IntPtr.Zero;
}
You need to call CheckMenuItem whenever you change Topmost. See the CheckMenuItem documentaton for details. Here's the P/Invoke signature and constants you'll need:
[DllImport("user32.dll")]
private static extern bool CheckMenuItem(IntPtr hMenu, Int32 uIDCheckItem, Int32 uCheck);
private const int MfChecked = 8;
private const int MfUnchecked = 0;
Now to check the item, just:
CheckMenuItem(systemMenuHandle, SettingsSysMenuId, MfChecked);
and to uncheck:
CheckMenuItem(systemMenuHandle, SettingsSysMenuId, MfUnchecked);
I need to be able to disable some of the checkboxes in a TreeView control of a WinForms application, but there's no such functionality built-in to the standard TreeView control.
I am already using the TreeView.BeforeCheck event and cancel it if the node is disabled and that works perfectly fine.
I also change the ForeColor of the disabled nodes to GrayText.
Does anyone have a simple and robust solution?
Since there's support in C++ we can resolve it using p/invoke.
Here's the setup for the p/invoke part, just make it available to the calling class.
// constants used to hide a checkbox
public const int TVIF_STATE = 0x8;
public const int TVIS_STATEIMAGEMASK = 0xF000;
public const int TV_FIRST = 0x1100;
public const int TVM_SETITEM = TV_FIRST + 63;
[DllImport("user32.dll")]
static extern IntPtr SendMessage(IntPtr hWnd, uint Msg, IntPtr wParam,
IntPtr lParam);
// struct used to set node properties
public struct TVITEM
{
public int mask;
public IntPtr hItem;
public int state;
public int stateMask;
[MarshalAs(UnmanagedType.LPTStr)]
public String lpszText;
public int cchTextMax;
public int iImage;
public int iSelectedImage;
public int cChildren;
public IntPtr lParam;
}
We want to determine on a node by node basis. The easiest way to do that is on the draw node event. We have to set our tree to be set as owner drawn in order for this event, so be sure to set that to something other than the default setting.
this.tree.DrawMode = TreeViewDrawMode.OwnerDrawText;
this.tree.DrawNode += new DrawTreeNodeEventHandler(tree_DrawNode);
In your tree_DrawNode function determine if the node being drawn is supposed to have a checkbox, and hide it when approriate. Then set the Default Draw property to true since we don't want to worry about drawing all the other details.
void tree_DrawNode(object sender, DrawTreeNodeEventArgs e)
{
if (e.Node.Level == 1)
{
HideCheckBox(e.Node);
e.DrawDefault = true;
}
else
{
e.Graphics.DrawString(e.Node.Text, e.Node.TreeView.Font,
Brushes.Black, e.Node.Bounds.X, e.Node.Bounds.Y);
}
}
Lastly, the actual call to the function we defined:
private void HideCheckBox(TreeNode node)
{
TVITEM tvi = new TVITEM();
tvi.hItem = node.Handle;
tvi.mask = TVIF_STATE;
tvi.stateMask = TVIS_STATEIMAGEMASK;
tvi.state = 0;
IntPtr lparam = Marshal.AllocHGlobal(Marshal.SizeOf(tvi));
Marshal.StructureToPtr(tvi, lparam, false);
SendMessage(node.TreeView.Handle, TVM_SETITEM, IntPtr.Zero, lparam);
}
This is PowerShell version, many thanks for #sam-trost for his life-savior code!
P/invoke:
$TypeDefinition = #'
using System;
using System.Runtime.InteropServices;
namespace Win32Functions {
public class Win32TreeView {
// constants used to hide a checkbox
public const int TVIF_STATE = 0x8;
public const int TVIS_STATEIMAGEMASK = 0xF000;
public const int TV_FIRST = 0x1100;
public const int TVM_SETITEM = TV_FIRST + 63;
[DllImport("user32.dll", SetLastError = true)]
public static extern IntPtr SendMessage(IntPtr hWnd, uint Msg, IntPtr wParam, IntPtr lParam);
// struct used to set node properties
public struct TVITEM
{
public int mask;
public IntPtr hItem;
public int state;
public int stateMask;
[MarshalAs(UnmanagedType.LPTStr)]
public String lpszText;
public int cchTextMax;
public int iImage;
public int iSelectedImage;
public int cChildren;
public IntPtr lParam;
}
}
}
'#
Add-Type -TypeDefinition $TypeDefinition -PassThru
Event handler:
$TreeView1_DrawNode = [System.Windows.Forms.DrawTreeNodeEventHandler]{
#Event Argument: $_ = [System.Windows.Forms.DrawTreeNodeEventArgs]
if ($null -ne $_.Node) {
# P/invoke hack to hide Node CheckBox
if ($_.Node.Level -eq 0) {
Hide-NodeCheckBox($_.Node)
}
$_.DrawDefault = $true
}
}
TreeView:
$TreeView1.DrawMode = [TreeViewDrawMode]::OwnerDrawText
$TreeView1.add_DrawNode($TreeView1_DrawNode)
Function:
function Hide-NodeCheckBox([TreeNode]$node) {
# P/invoke hack to hide Node CheckBox
if ($node.TreeView.CheckBoxes) {
$tvi = [Win32Functions.Win32TreeView+TVITEM]::new()
$tvi.hItem = $node.Handle
$tvi.mask = [Win32Functions.Win32TreeView]::TVIF_STATE
$tvi.stateMask = [Win32Functions.Win32TreeView]::TVIS_STATEIMAGEMASK
$tvi.state = 0
[IntPtr]$lparam = [Marshal]::AllocHGlobal([Marshal]::SizeOf($tvi))
[Marshal]::StructureToPtr($tvi, $lparam, $false)
[Win32Functions.Win32TreeView]::SendMessage($node.TreeView.Handle, [Win32Functions.Win32TreeView]::TVM_SETITEM, [IntPtr]::Zero, $lparam)
}
}
TreeView.BeforeCheck -- register for this event, check whether the node is one where the checkboxes are allowed to be checked or not and, if it cannot be checked then you can cancel the event by setting the Cancel property on the TreeViewCancelEventArgs. That should hopefully prevent the user from checking those boxes but will not make for the best user-experience.
To remove the checkboxes for the non-checkable items, you could possibly use owner-draw to draw a solid rectangle over the check-box to remove it.
There is nothing inbuilt to do this. You can use the BeforeCheck event and cancel it for the desired nodes. In case the appearance of the checkbox matters, then you will need to place a image there to show the checkbox disabled.
This link might be of your interest.
If I use dragMove the wpf window will not move to a location where the y value is negative. I can however set the windows top value to a negative value. Is there a simple way to enable dragMove to allow the top of the window to be moved above the displays 0 position?
Edit:
It seems that this is the default window's handling of moveWindow. Verified with a call to SendMessage( hwnd, WM_SYSCOMMAND, SC_MOVE, null);
As I found, the window will move to "negative" location, but will then jump back. To prevent this you could do something like:
public partial class Window1: Window {
public Window1() {
InitializeComponent();
}
private void Window_MouseDown(object sender, MouseButtonEventArgs e) {
DragMove();
}
public struct WINDOWPOS {
public IntPtr hwnd;
public IntPtr hwndInsertAfter;
public int x;
public int y;
public int cx;
public int cy;
public UInt32 flags;
};
private static IntPtr WndProc(IntPtr hwnd, int msg, IntPtr wParam, IntPtr lParam, ref bool handled) {
switch(msg) {
case 0x46://WM_WINDOWPOSCHANGING
if(Mouse.LeftButton != MouseButtonState.Pressed) {
WINDOWPOS wp = (WINDOWPOS)Marshal.PtrToStructure(lParam, typeof(WINDOWPOS));
wp.flags = wp.flags | 2; //SWP_NOMOVE
Marshal.StructureToPtr(wp, lParam, false);
}
break;
}
return IntPtr.Zero;
}
private void Window_Loaded(object sender, RoutedEventArgs e) {
HwndSource source = HwndSource.FromHwnd(new WindowInteropHelper(this).Handle);
source.AddHook(new HwndSourceHook(WndProc));
}
}
Handling WM_WINDOWPOSCHANGING this way will prevent any movement of the window unless left mouse button is pressed. This includes maximizing the window and programmatic change of window position as well, so you'll have to adapt the code if you need another behavior.