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Block Control+Alt+Delete
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Is there any method to disable logoff,lock and taskmanager in ctrl+alt+del in C#
(4 answers)
Closed 1 year ago.
I have a dashboard that goes full screen. Looking to make it more of a "Kiosk" view that users can't easily bypass to get to the desktop. More for routine tamper prevention. I have a button on top right for a menu that I want to keep enabled and allows a pin to be entered to close the app.
Is there a function call or library I should look into to block user activity or would I just set all controls to enable=false, etc? but they can still hit the Windows or Ctrl+Alt+Delete which I would like to prevent also.
Create a FormClosing property and write the following code to disable the user closing the form.
private void FormName_FormClosing(object sender, FormClosingEventArgs e)
{
e.Cancel = (e.CloseReason == CloseReason.UserClosing);
}
I also have the following code (from here) if you want to go a step further and disable the function keys example. ctrl+shift+esc (opens task manager) etc.
Put this into the FormName_Load
ProcessModule objCurrentModule = Process.GetCurrentProcess().MainModule;
objKeyboardProcess = new LowLevelKeyboardProc(captureKey);
ptrHook = SetWindowsHookEx(13, objKeyboardProcess, GetModuleHandle(objCurrentModule.ModuleName), 0);
Then put this under public partial class FormName : Form
/* Code to Disable WinKey, Alt+Tab, Ctrl+Shift+Esc Starts Here */
// Structure contain information about low-level keyboard input event
[StructLayout(LayoutKind.Sequential)]
private struct KBDLLHOOKSTRUCT
{
public Keys key;
public int scanCode;
public int flags;
public int time;
public IntPtr extra;
}
//System level functions to be used for hook and unhook keyboard input
private delegate IntPtr LowLevelKeyboardProc(int nCode, IntPtr wParam, IntPtr lParam);
[DllImport("user32.dll", CharSet = CharSet.Auto, SetLastError = true)]
private static extern IntPtr SetWindowsHookEx(int id, LowLevelKeyboardProc callback, IntPtr hMod, uint dwThreadId);
[DllImport("user32.dll", CharSet = CharSet.Auto, SetLastError = true)]
private static extern bool UnhookWindowsHookEx(IntPtr hook);
[DllImport("user32.dll", CharSet = CharSet.Auto, SetLastError = true)]
private static extern IntPtr CallNextHookEx(IntPtr hook, int nCode, IntPtr wp, IntPtr lp);
[DllImport("kernel32.dll", CharSet = CharSet.Auto, SetLastError = true)]
private static extern IntPtr GetModuleHandle(string name);
[DllImport("user32.dll", CharSet = CharSet.Auto)]
private static extern short GetAsyncKeyState(Keys key);
//Declaring Global objects
private IntPtr ptrHook;
private LowLevelKeyboardProc objKeyboardProcess;
private IntPtr captureKey(int nCode, IntPtr wp, IntPtr lp)
{
if (nCode >= 0)
{
KBDLLHOOKSTRUCT objKeyInfo = (KBDLLHOOKSTRUCT)Marshal.PtrToStructure(lp, typeof(KBDLLHOOKSTRUCT));
// Disabling Windows keys
if (objKeyInfo.key == Keys.RWin || objKeyInfo.key == Keys.LWin || objKeyInfo.key == Keys.Tab && HasAltModifier(objKeyInfo.flags) || objKeyInfo.key == Keys.Escape && (ModifierKeys & Keys.Control) == Keys.Control)
{
return (IntPtr)1; // if 0 is returned then All the above keys will be enabled
}
}
return CallNextHookEx(ptrHook, nCode, wp, lp);
}
bool HasAltModifier(int flags)
{
return (flags & 0x20) == 0x20;
}
/* Code to Disable WinKey, Alt+Tab, Ctrl+Shift+Esc Ends Here */
Make sure you are also using these
using System;
using System.Threading.Tasks;
using System.Windows.Forms;
using System.Runtime.InteropServices;
using System.Diagnostics;
using System.IO;
System.Diagnostics; and System.Runtime.InteropServices; to be specific.
With these changes I recommend making an "emergency escape" in case you want to exit.
You could also put the app into startup for it to start once the machine is logged on.
code for this:
if (File.Exists(Environment.GetFolderPath(Environment.SpecialFolder.Startup).Trim() + "\\FILE.exe") == false)
{
File.Move(Application.StartupPath + "\\FILE.exe", Environment.GetFolderPath(Environment.SpecialFolder.Startup).Trim() + "\\FILE.exe");
}
I suggest making this a try catch statement if an exception is thrown for the file already being inside startup
How can I show/hide the desktop icons programmatically, using C#?
I'm trying to create an alternative desktop, which uses widgets, and I need to hide the old icons.
You can do this using the Windows API. Here is sample code in C# that will toggle desktop icons.
[DllImport("user32.dll", SetLastError = true)] static extern IntPtr FindWindow(string lpClassName, string lpWindowName);
[DllImport("user32.dll", SetLastError = true)] static extern IntPtr GetWindow(IntPtr hWnd, GetWindow_Cmd uCmd);
enum GetWindow_Cmd : uint
{
GW_HWNDFIRST = 0,
GW_HWNDLAST = 1,
GW_HWNDNEXT = 2,
GW_HWNDPREV = 3,
GW_OWNER = 4,
GW_CHILD = 5,
GW_ENABLEDPOPUP = 6
}
[DllImport("user32.dll", CharSet = CharSet.Auto)] static extern IntPtr SendMessage(IntPtr hWnd, UInt32 Msg, IntPtr wParam, IntPtr lParam);
private const int WM_COMMAND = 0x111;
static void ToggleDesktopIcons()
{
var toggleDesktopCommand = new IntPtr(0x7402);
IntPtr hWnd = GetWindow(FindWindow("Progman", "Program Manager"), GetWindow_Cmd.GW_CHILD);
SendMessage(hWnd, WM_COMMAND, toggleDesktopCommand, IntPtr.Zero);
}
This sends a message to the SHELLDLL_DefView child window of Progman, which tells it to toggle visibility (by adding or removing the WS_VISIBLE style) of it's only child, "FolderView". "FolderView" is the actual window that contains the icons.
To test to see if icons are visible or not, you can query for the WS_VISIBLE style by using the GetWindowInfo function, shown below:
[return: MarshalAs(UnmanagedType.Bool)]
[DllImport("user32.dll", SetLastError = true)]
private static extern bool GetWindowInfo(IntPtr hwnd, ref WINDOWINFO pwi);
[StructLayout(LayoutKind.Sequential)]
public struct RECT
{
private int _Left;
private int _Top;
private int _Right;
private int _Bottom;
}
[StructLayout(LayoutKind.Sequential)]
struct WINDOWINFO
{
public uint cbSize;
public RECT rcWindow;
public RECT rcClient;
public uint dwStyle;
public uint dwExStyle;
public uint dwWindowStatus;
public uint cxWindowBorders;
public uint cyWindowBorders;
public ushort atomWindowType;
public ushort wCreatorVersion;
public WINDOWINFO(Boolean? filler)
: this() // Allows automatic initialization of "cbSize" with "new WINDOWINFO(null/true/false)".
{
cbSize = (UInt32)(Marshal.SizeOf(typeof(WINDOWINFO)));
}
}
Here is a function that calls the above code and returns true if the window is visible, false if not.
static bool IsVisible()
{
IntPtr hWnd = GetWindow(GetWindow(FindWindow("Progman", "Program Manager"), GetWindow_Cmd.GW_CHILD), GetWindow_Cmd.GW_CHILD);
WINDOWINFO info = new WINDOWINFO();
info.cbSize = (uint)Marshal.SizeOf(info);
GetWindowInfo(hWnd, ref info);
return (info.dwStyle & 0x10000000) == 0x10000000;
}
The windows API code along with more information about the window styles can be found here: http://www.pinvoke.net/default.aspx/user32/GetWindowInfo.html
Even though this is quite old when I tried Ondrej Balas's answer, one problem I found with this solution is that it does not work if the ToggleDesktop command is used to show the desktop ( also if wallpaper rotation is enabled ).
In both of these cases the SHELLDLL_DefView window, which is the recipient of the toggleDesktopCommand in the ToggleDesktopIcons function, is not a child of the "Program manager" window but of a 'WorkerW" window. (see WinApi - How to obtain SHELLDLL_DefView and Windows Desktop ListView Handle.
Based on those and building upon Ondrej Balas's earlier answer change the ToggleDesktopIcons function to be :
static void ToggleDesktopIcons()
{
var toggleDesktopCommand = new IntPtr(0x7402);
SendMessage(GetDesktopSHELLDLL_DefView(), WM_COMMAND, toggleDesktopCommand, IntPtr.Zero);
}
And add a GetDesktopSHELLDLL_DefView function:
[DllImport("user32.dll", SetLastError = true)]
public static extern IntPtr FindWindowEx(IntPtr parentHandle, IntPtr childAfter, string className, string windowTitle);
[DllImport("user32.dll", SetLastError = false)]
static extern IntPtr GetDesktopWindow();
static IntPtr GetDesktopSHELLDLL_DefView()
{
var hShellViewWin = IntPtr.Zero;
var hWorkerW = IntPtr.Zero;
var hProgman = FindWindow("Progman", "Program Manager");
var hDesktopWnd = GetDesktopWindow();
// If the main Program Manager window is found
if (hProgman != IntPtr.Zero)
{
// Get and load the main List view window containing the icons.
hShellViewWin = FindWindowEx(hProgman, IntPtr.Zero, "SHELLDLL_DefView", null);
if (hShellViewWin == IntPtr.Zero)
{
// When this fails (picture rotation is turned ON, toggledesktop shell cmd used ), then look for the WorkerW windows list to get the
// correct desktop list handle.
// As there can be multiple WorkerW windows, iterate through all to get the correct one
do
{
hWorkerW = FindWindowEx(hDesktopWnd, hWorkerW, "WorkerW", null);
hShellViewWin = FindWindowEx(hWorkerW, IntPtr.Zero, "SHELLDLL_DefView", null);
} while (hShellViewWin == IntPtr.Zero && hWorkerW != IntPtr.Zero);
}
}
return hShellViewWin;
}
Now regardless of the desktop toggle or wallpaper rotation the ToggleDesktopIcons should always work.
For reference this is my toggle desktop function which caused the issue with the original ToggleDesktopIcons function
static public void ToggleDesktop(object sender, EventArgs e)
{
var shellObject = new Shell32.Shell();
shellObject.ToggleDesktop();
}
In response to James M, this function returns the current state:
bool IconsVisible()
{
var hWnd = GetDesktopListView();
var info = new User32.WINDOWINFO(null);
User32.GetWindowInfo(hWnd, ref info);
return (info.dwStyle & User32.WindowStyle.WS_VISIBLE) == User32.WindowStyle.WS_VISIBLE;
}
A different approach is to create a separate desktop and show it instead. It will not have icons.
Application running itself on a separate desktop
You can do this in RegEdit
HKEY_CURRENT_USER\SOFTWARE\Microsoft\Windows\CurrentVersion\Explorer\Advanced
change HideIcons to 1
static void HideIcons()
{
RegistryKey myKey = Registry.CurrentUser.OpenSubKey(#"SOFTWARE\Microsoft\Windows\CurrentVersion\Explorer\Advanced", true);
if (myKey != null)
{
myKey.SetValue("HideIcons", 1);
myKey.Close();
}
}
Use the Registry class as described here.
http://msdn.microsoft.com/en-us/library/microsoft.win32.registry.aspx
You can create a full screen view application and make it the top most window.
Then make your application to be start up with windows.
You are going about this the wrong way. What you are really trying to do is to replace the shell. Windows provides for this so you should just take advantage of it. Write your own shell to replace explorer.
Nice topic. Without actually creating a different desktop it would be visually pleasant to have the running applications minimized in the same swoop.
I have looked at this question and answer
How to send text to Notepad in C#/Win32?
A slight variation that I think shouldn't matter.. Is that I have a bunch of notepad windows.. So to test this I copied notepad.exe to be notepadd.exe and opened notepadd.exe, so only one of my notepad windows is the notepadd.exe process.
I have this code
using System;
using System.Windows.Forms;
using System.Runtime.InteropServices;
using System.Diagnostics;
namespace testsendmessage
{
public partial class Form1 : Form
{
[DllImport("user32.dll", EntryPoint = "FindWindowEx")]
public static extern IntPtr FindWindowEx(IntPtr hwndParent, IntPtr hwndChildAfter, string lpszClass, string lpszWindow);
[DllImport("User32.dll")]
public static extern int SendMessage(IntPtr hWnd, int uMsg, int wParam, string lParam);
public Form1()
{
InitializeComponent();
}
private void Form1_Load(object sender, EventArgs e)
{
}
private void button1_Click(object sender, EventArgs e)
{
Process[] notepads = Process.GetProcessesByName("notepadd");
if (notepads.Length == 0) return;
if (notepads[0] != null)
{
IntPtr child = FindWindowEx(notepads[0].MainWindowHandle, new IntPtr(0), "Edit", null);
SendMessage(child, 0x000C, 0, "abcd");
}
}
}
}
It's not touching the notepad window though.
I tried debugging and I see that the notepads array has one item, which is certainly correct.
And it gets within the 'if' and it runs SendMessage(child, 0x000C, 0, "abcd");
But I see nothing appearing in the notepad window
I'm not getting an error from the code it's just nothing appearing in the notepad window.. And I don't really understand winapi stuff much, so i'm not sure how to proceed in trying to solve it?
As you can see it reaches that line, and I can use the watch window to look at the notepads Process array, and at 'child' but I don't know what I should be looking at to determine why it's not sending to the window
Added
New code based on Remy's suggestion
using System;
using System.Windows.Forms;
using System.Runtime.InteropServices;
using System.Diagnostics;
namespace testsendmessage
{
public partial class Form1 : Form
{
[DllImport("user32.dll", EntryPoint = "FindWindowEx")]
public static extern IntPtr FindWindowEx(IntPtr hwndParent, IntPtr hwndChildAfter, string lpszClass, string lpszWindow);
[DllImport("User32.dll", CharSet = CharSet.Unicode, EntryPoint = "SendMessageW")]
public static extern IntPtr SendMessageWStr(IntPtr hWnd, uint uMsg, IntPtr wParam, string lParam);
const uint WM_SETTEXT = 0x000C;
public Form1()
{
InitializeComponent();
}
private void Form1_Load(object sender, EventArgs e)
{
}
private void button1_Click(object sender, EventArgs e)
{
Process[] notepads = Process.GetProcessesByName("notepadd");
if (notepads.Length == 0) return;
if (notepads[0] != null)
{
IntPtr child = FindWindowEx(notepads[0].MainWindowHandle, new IntPtr(0), "Edit", null);
SendMessageWStr(child, WM_SETTEXT, IntPtr.Zero, "abcd");
}
}
}
}
But I still get the same issue that the notepad window was blank before clicking button and is blank after too. It's not sending the text to the notepadd window. Despite the fact that it is reaching that line of code that is meant to send the text to it.
Further addition.
Current code,
I've changed FindWindowEx to FindWindowExW and i've changed new IntPtr(0) to IntPtr.Zero and it still is unresponsive.
I've opened up notepadd.exe from cmd, I see the window there. And of course notepadd.exe in task manger, But clicking the button in my application is not writing any text into that window.
using System;
using System.Windows.Forms;
using System.Runtime.InteropServices;
using System.Diagnostics;
namespace testsendmessage
{
public partial class Form1 : Form
{
[DllImport("user32.dll", EntryPoint = "FindWindowExW")]
public static extern IntPtr FindWindowExW(IntPtr hwndParent, IntPtr hwndChildAfter, string lpszClass, string lpszWindow);
[DllImport("User32.dll", CharSet = CharSet.Unicode, EntryPoint = "SendMessageW")]
public static extern IntPtr SendMessageWStr(IntPtr hWnd, uint uMsg, IntPtr wParam, string lParam);
const uint WM_SETTEXT = 0x000C;
public Form1()
{
InitializeComponent();
}
private void Form1_Load(object sender, EventArgs e)
{
}
private void button1_Click(object sender, EventArgs e)
{
Process[] notepads = Process.GetProcessesByName("notepadd");
if (notepads.Length == 0) return;
if (notepads[0] != null)
{
IntPtr child = FindWindowExW(notepads[0].MainWindowHandle, IntPtr.Zero, "Edit", null);
SendMessageWStr(child, WM_SETTEXT, IntPtr.Zero, "abcd");
}
}
}
}
Much credit to Remy. After some troubleshooting I ended up finding the code worked so it's a mystery why I was finding it didn't.
A good troubleshooting step is to try moving the window around with nircmd, so you know you have the handle.
To get the handle of the window, you can use nirsoft winlister, or winspector
You can use nircmd commands like nircmd win close handle 0x00230632 change that 0x00230632 to whatever you find the handle to be. Or better don't close it(otherwise you'll have to reopen it and the new window will have a new handle), so a command like nircmd win move handle 0x00B917AE 80 10 100 100 So you know the handle is right, regardless of any issue with the code.
Winspector also shows the child of the notepad window
Going back to the C# code, you can
skip the child and try writing into the parent, it should write into the title of the window
Try using SendMessage to specify a window directly. You write the handle in decimal rather than hex. e.g. if the handle is 3479948 then
e.g. SendMessage(new IntPtr(3479948), WM_SETTEXT, IntPtr.Zero, "abcdee");
You can also check that notepads[0].MainWindowHandle is picking up the correct value.. the handle shown in winspector.
You can look at the IntPtr child = FindWindowEx(...) line, make sure the 'child' is picking up the child handle.
You can try writing to that one directly with SendMessage. e.g. SendMessage(new IntPtr(1234567), WM_SETTEXT, IntPtr.Zero, "abcdee"); // (if winspector shows the child window to be that handle).
I want to simulate F5 key press in my C# program. When IE is open, I want to be able refresh my website automatically.
How can I do that?
Here's an example...
static class Program
{
[DllImport("user32.dll")]
public static extern int SetForegroundWindow(IntPtr hWnd);
[STAThread]
static void Main()
{
while(true)
{
Process [] processes = Process.GetProcessesByName("iexplore");
foreach(Process proc in processes)
{
SetForegroundWindow(proc.MainWindowHandle);
SendKeys.SendWait("{F5}");
}
Thread.Sleep(5000);
}
}
}
a better one... less anoying...
static class Program
{
const UInt32 WM_KEYDOWN = 0x0100;
const int VK_F5 = 0x74;
[DllImport("user32.dll")]
static extern bool PostMessage(IntPtr hWnd, UInt32 Msg, int wParam, int lParam);
[STAThread]
static void Main()
{
while(true)
{
Process [] processes = Process.GetProcessesByName("iexplore");
foreach(Process proc in processes)
PostMessage(proc.MainWindowHandle, WM_KEYDOWN, VK_F5, 0);
Thread.Sleep(5000);
}
}
}
You can use the Win32 API FindWindow or FindWindowEx to find the window handle of the open browser and then just call SendMessage with WM_KEYDOWN. Typically it's easiest just to pass the window caption to FindWindowEx and have it find the associated window handle for you.
If you are starting the browser process yourself via a Process process object then you can use process.MainWindowHandle instead of calling FindWindowEx.
Spy++ is a very useful tool when you want to start working with other windows. It basically allows you to learn another program's hierarchy of UI elements. You can also monitor all of the messages that go into the window you're monitoring. I have more info in this thread.
The F5 keystroke has this virtual key code:
const int VK_F5 = 0x74;
The p/invoke signature for FindWindowEx in C# is:
[DllImport("user32.dll", SetLastError = true)]
static extern IntPtr FindWindowEx(IntPtr hwndParent, IntPtr hwndChildAfter, string lpszClass, string lpszWindow);
You can p/invoke (bring in) the Win32 API SendMessage like this:
[DllImport("user32.dll", CharSet = CharSet.Auto)]
static extern IntPtr SendMessage(IntPtr hWnd, UInt32 Msg, IntPtr wParam, IntPtr lParam);
So to recap, you call FindWindowEx directly from your C# code after having the above code somewhere inside your class. FindWindowEx will return a window handle. Then once you have the window handle, you can send any keystroke(s) to the window, or call many other Win32 API calls on the window handle. Or even find a child window by using another call to FindWindowEx. For example you could select the edit control of the browser even and then change it's text.
If all else goes wrong and you think you're sending the right key to the window, you can use spy++ to see what messages are sent to the window when you manually set focus to the browser and manually press F5.
The easiest way to send (simulate) KeyStrokes to any window is to use the SendKeys.Send method of .NET Framework.
Checkout this very intuitive MSDN article http://msdn.microsoft.com/en-us/library/system.windows.forms.sendkeys.aspx
Particularly for your case, if your browser window is in focus, sending F5 would just involve the following line of code:
SendKeys.Send("{F5}");
Simple one, add before Main
[DllImport("USER32.DLL", CharSet = CharSet.Unicode)]
public static extern IntPtr FindWindow(string lpClassName, string lpWindowName);
[DllImport("USER32.DLL")]
public static extern bool SetForegroundWindow(IntPtr hWnd);
Code inside Main/Method:
string className = "IEFrame";
string windowName = "New Tab - Windows Internet Explorer";
IntPtr IE = FindWindow(className, windowName);
if (IE == IntPtr.Zero)
{
return;
}
SetForegroundWindow(IE);
InputSimulator.SimulateKeyPress(VirtualKeyCode.F5);
Note:
Add InputSimulator as reference. To download Click here
To find Class & Window name, use WinSpy++. To download Click here
Another alternative to simulating a F5 key press would be to simply host the WebBrowser control in the Window Forms application. You use the WebBrowser.Navigate method to load your web page and then use a standard Timer and on each tick of the timer you just re-Navigate to the url which will reload the page.
Easy, short and no need window focus:
Also here a usefull list of Virtual Key Codes
[DllImport("user32.dll")]
public static extern IntPtr FindWindow(string lpClassName, string lpWindowName);
[DllImport("user32.dll")]
static extern bool PostMessage(IntPtr hWnd, UInt32 Msg, int wParam, int lParam);
private void button1_Click(object sender, EventArgs e)
{
const int WM_SYSKEYDOWN = 0x0104;
const int VK_F5 = 0x74;
IntPtr WindowToFind = FindWindow(null, "Google - Mozilla Firefox");
PostMessage(WindowToFind, WM_SYSKEYDOWN, VK_F5, 0);
}
Use mouse_event or keybd_event. They say not to use them anymore but you don't have to find the window at all.
using System;
using System.Runtime.InteropServices;
public class SimulatePCControl
{
[DllImport("user32.dll", CharSet = CharSet.Auto, CallingConvention = CallingConvention.StdCall)]
public static extern void keybd_event(uint bVk, uint bScan, uint dwFlags, uint dwExtraInfo);
private const int VK_LEFT = 0x25;
public static void LeftArrow()
{
keybd_event(VK_LEFT, 0, 0, 0);
}
}
Virtual Key Codes are here for this one: http://www.kbdedit.com/manual/low_level_vk_list.html
Also for mouse:
using System.Runtime.InteropServices;
using UnityEngine;
public class SimulateMouseClick
{
[DllImport("user32.dll", CharSet = CharSet.Auto, CallingConvention = CallingConvention.StdCall)]
public static extern void mouse_event(uint dwFlags, uint dx, uint dy, uint cButtons, uint dwExtraInfo);
//Mouse actions
private const int MOUSEEVENTF_LEFTDOWN = 0x02;
private const int MOUSEEVENTF_LEFTUP = 0x04;
private const int MOUSEEVENTF_RIGHTDOWN = 0x08;
private const int MOUSEEVENTF_RIGHTUP = 0x10;
public static void Click()
{
//Call the imported function with the cursor's current position
uint X = (uint)0;
uint Y = (uint)0;
mouse_event(MOUSEEVENTF_LEFTDOWN | MOUSEEVENTF_LEFTUP, X, Y, 0, 0);
Debug.LogError("SIMULATED A MOUSE CLICK JUST NOW...");
}
//...other code needed for the application
}
Instead of forcing an F5 keypress when you're just trying to get the page to postback, you can call a postback based on a JS event (even mousemove or timer_tick if you want it to fire all the time). Use the code at http://weblogs.asp.net/mnolton/archive/2003/06/04/8260.aspx as a reference.
I want to get the MessageBoxIcons, that get displayed when the user is presented with a MessageBox. Earlier I used SystemIcons for that purpose, but now it seems that it returns icons different than the ones on the MessageBox.
This leads to the conclusion that in Windows 8.1 SystemIcons and MessageBoxIcons are different. I know that icons are taken using WinApi MessageBox, but I can't seem to get the icons themselves in any way.
I would like to ask for a way of retrieving those icons.
Update:
You should use the SHGetStockIconInfo function.
To do that in C# you will have to define a few enums and structs (consult this excellent page for more information):
public enum SHSTOCKICONID : uint
{
//...
SIID_INFO = 79,
//...
}
[Flags]
public enum SHGSI : uint
{
SHGSI_ICONLOCATION = 0,
SHGSI_ICON = 0x000000100,
SHGSI_SYSICONINDEX = 0x000004000,
SHGSI_LINKOVERLAY = 0x000008000,
SHGSI_SELECTED = 0x000010000,
SHGSI_LARGEICON = 0x000000000,
SHGSI_SMALLICON = 0x000000001,
SHGSI_SHELLICONSIZE = 0x000000004
}
[StructLayoutAttribute(LayoutKind.Sequential, CharSet = CharSet.Unicode)]
public struct SHSTOCKICONINFO
{
public UInt32 cbSize;
public IntPtr hIcon;
public Int32 iSysIconIndex;
public Int32 iIcon;
[MarshalAs(UnmanagedType.ByValTStr, SizeConst = 260/*MAX_PATH*/)]
public string szPath;
}
[DllImport("Shell32.dll", SetLastError = false)]
public static extern Int32 SHGetStockIconInfo(SHSTOCKICONID siid, SHGSI uFlags, ref SHSTOCKICONINFO psii);
After that you can easily get the required icon:
SHSTOCKICONINFO sii = new SHSTOCKICONINFO();
sii.cbSize = (UInt32)Marshal.SizeOf(typeof(SHSTOCKICONINFO));
Marshal.ThrowExceptionForHR(SHGetStockIconInfo(SHSTOCKICONID.SIID_INFO,
SHGSI.SHGSI_ICON ,
ref sii));
pictureBox1.Image = Icon.FromHandle(sii.hIcon).ToBitmap();
This is how the result will look like:
Please note:
If this function returns an icon handle in the hIcon member of the
SHSTOCKICONINFO structure pointed to by psii, you are responsible for
freeing the icon with DestroyIcon when you no longer need it.
i will not delete my original answer, as - I think - it contains useful information regarding this issue, and another way (or workaround) of retrieving this icon.
Original answer:
Quite interestingly the icons present in the SystemIcons differ from the ones displayed on the MessageBoxes in the case of Asterisk, Information and Question. The icons on the dialog look much flatter.
In all other cases they look exactly the same, e.g.: in case of Error:
When you try to get the icon using the SystemIcons you get the one on the left in the above images.
// get icon from SystemIcons
pictureBox1.Image = SystemIcons.Asterisk.ToBitmap();
If you try a little bit harder, using the LoadIcon method from user32.dll, you still get the same icon (as it can be seen in center of the above images).
[DllImport("user32.dll")]
static extern IntPtr LoadIcon(IntPtr hInstance, IntPtr lpIconName);
...
public enum SystemIconIds
{
...
IDI_ASTERISK = 32516,
...
}
...
// load icon by ID
IntPtr iconHandle = LoadIcon(IntPtr.Zero, new IntPtr((int)SystemIconIds.IDI_ASTERISK));
pictureBox2.Image = Icon.FromHandle(iconHandle).ToBitmap();
But when you show a MessagBox you get a different one (as seen in the MessageBox on the images). One has no other choice, but to get that very icon from the MessageBox.
For that we will need a few more DllImports:
// To be able to find the dialog window
[DllImport("user32.dll", SetLastError = true)]
static extern IntPtr FindWindow(string lpClassName, string lpWindowName);
// To be able to get the icon window handle
[DllImport("user32.dll")]
static extern IntPtr GetDlgItem(IntPtr hDlg, int nIDDlgItem);
// To be able to get a handle to the actual icon
[DllImport("user32.dll", CharSet = CharSet.Auto)]
static extern IntPtr SendMessage(IntPtr hWnd, UInt32 Msg, IntPtr wParam, IntPtr lParam);
The idea is the following: First we display a MessageBox, after that (while it is still displayed) we find it's handle, using that handle we will get another handle, now to the static control which is containing the icon. In the end we will send a message to that control (an STM_GETICON message), which will return with a handle to the icon itself. Using that handle we can create an Icon, which we can use anywhere in our application.
In code:
// show a `MessageBox`
MessageBox.Show("test", "test caption", MessageBoxButtons.OK, MessageBoxIcon.Asterisk);
...
var hwnd = FindWindow(null, "test caption");
if (hwnd != IntPtr.Zero)
{
// we got the messagebox, get the icon from it
IntPtr hIconWnd = GetDlgItem(hwnd, 20);
if (hIconWnd != IntPtr.Zero)
{
var iconHandle = SendMessage(hIconWnd, 369/*STM_GETICON*/, IntPtr.Zero, IntPtr.Zero);
pictureBox3.Image = Icon.FromHandle(iconHandle).ToBitmap();
}
}
After the code runs the PictureBox called pictureBox3 will display the same image as the MessageBox (as it can be seen on the right on the image).
I really hope this helps.
For reference here is all the code (it's a WinForms app, the Form has three PicturBoxes and one Timer, their names can be deducted from the code...):
using System;
using System.Drawing;
using System.Runtime.InteropServices;
using System.Windows.Forms;
namespace WindowsFormsApplication1
{
public partial class Form1 : Form
{
[DllImport("user32.dll")]
static extern IntPtr LoadIcon(IntPtr hInstance, IntPtr lpIconName);
[DllImport("user32.dll", SetLastError = true)]
static extern IntPtr FindWindow(string lpClassName, string lpWindowName);
[DllImport("user32.dll")]
static extern IntPtr GetDlgItem(IntPtr hDlg, int nIDDlgItem);
[DllImport("user32.dll", CharSet = CharSet.Auto)]
static extern IntPtr SendMessage(IntPtr hWnd, UInt32 Msg, IntPtr wParam, IntPtr lParam);
public enum SystemIconIds
{
IDI_APPLICATION = 32512,
IDI_HAND = 32513,
IDI_QUESTION = 32514,
IDI_EXCLAMATION = 32515,
IDI_ASTERISK = 32516,
IDI_WINLOGO = 32517,
IDI_WARNING = IDI_EXCLAMATION,
IDI_ERROR = IDI_HAND,
IDI_INFORMATION = IDI_ASTERISK,
}
public Form1()
{
InitializeComponent();
// Information, Question and Asterix differ from the icons displayed on MessageBox
// get icon from SystemIcons
pictureBox1.Image = SystemIcons.Asterisk.ToBitmap();
// load icon by ID
IntPtr iconHandle = LoadIcon(IntPtr.Zero, new IntPtr((int)SystemIconIds.IDI_ASTERISK));
pictureBox2.Image = Icon.FromHandle(iconHandle).ToBitmap();
}
private void pictureBox1_Click(object sender, EventArgs e)
{
MessageBox.Show("test", "test caption", MessageBoxButtons.OK, MessageBoxIcon.Asterisk);
}
private void timer1_Tick(object sender, EventArgs e)
{
var hwnd = FindWindow(null, "test caption");
if (hwnd != IntPtr.Zero)
{
// we got the messagebox, get the icon from it
IntPtr hIconWnd = GetDlgItem(hwnd, 20);
if (hIconWnd != IntPtr.Zero)
{
var iconHandle = SendMessage(hIconWnd, 369/*STM_GETICON*/, IntPtr.Zero, IntPtr.Zero);
pictureBox3.Image = Icon.FromHandle(iconHandle).ToBitmap();
}
}
}
}
}