TreeView Remove CheckBox by some Nodes - c#

I want remove CheckBoxes where the Node.Type is 5 or 6. I use this code:
private void TvOne_DrawNode(object sender, DrawTreeNodeEventArgs e)
{
int type = (e.Node as Node).typ;
if (type == 5 || type == 6)
{
Color backColor, foreColor;
if ((e.State & TreeNodeStates.Selected) == TreeNodeStates.Selected)
{
backColor = SystemColors.Highlight;
foreColor = SystemColors.HighlightText;
}
else if ((e.State & TreeNodeStates.Hot) == TreeNodeStates.Hot)
{
backColor = SystemColors.HotTrack;
foreColor = SystemColors.HighlightText;
}
else
{
backColor = e.Node.BackColor;
foreColor = e.Node.ForeColor;
}
using (SolidBrush brush = new SolidBrush(backColor))
{
e.Graphics.FillRectangle(brush, e.Node.Bounds);
}
TextRenderer.DrawText(e.Graphics, e.Node.Text, this.TvOne.Font,
e.Node.Bounds, foreColor, backColor);
if ((e.State & TreeNodeStates.Focused) == TreeNodeStates.Focused)
{
ControlPaint.DrawFocusRectangle(e.Graphics, e.Node.Bounds,
foreColor, backColor);
}
e.DrawDefault = false;
}
else
{
e.DrawDefault = true;
}
}
The Problem is that then the Image and the Line to the Root Node is not there.
How can Remove the Checkbox and let the Image and the Line there?
This is wrong!

In the code you've shown, you are handling the drawing yourself for all of the nodes whose type is either 5 or 6. For the rest of the types, you're simply allowing the system to draw the nodes in the default way. That's why they all have the lines as expected, but the ones you're owner-drawing do not: You forgot to draw in the lines! You see, when you say e.DrawDefault = false; it's assumed that you really do mean it. None of the regular drawing is done, including the standard lines.
You'll either need to draw in those lines yourself, or figure out how to get by without owner-drawing at all.
From the code you have now, it looks like you're trying to simulate the system's native drawing style as much as possible in your owner-draw code, so it's not clear to me what exactly you accomplish by owner-drawing in the first place. If you're just trying to keep checkboxes from showing up for type 5 and 6 nodes (which, like the lines, are simply not getting drawn because you aren't drawing them!), there's a simpler way to do that without involving owner drawing.
So, you ask, what is that simpler way to hide the checkboxes for individual nodes? Well, it turns out that the TreeView control itself actually supports this, but that functionality is not exposed in the .NET Framework. You need to P/Invoke and call the Windows API to get at it. Add the following code to your form class (make sure you've added a using declaration for System.Runtime.InteropServices):
private const int TVIF_STATE = 0x8;
private const int TVIS_STATEIMAGEMASK = 0xF000;
private const int TV_FIRST = 0x1100;
private const int TVM_SETITEM = TV_FIRST + 63;
[StructLayout(LayoutKind.Sequential, Pack = 8, CharSet = CharSet.Auto)]
private 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;
}
[DllImport("user32.dll", CharSet = CharSet.Auto)]
private static extern IntPtr SendMessage(IntPtr hWnd, int Msg, IntPtr wParam,
ref TVITEM lParam);
/// <summary>
/// Hides the checkbox for the specified node on a TreeView control.
/// </summary>
private void HideCheckBox(TreeView tvw, TreeNode node)
{
TVITEM tvi = new TVITEM();
tvi.hItem = node.Handle;
tvi.mask = TVIF_STATE;
tvi.stateMask = TVIS_STATEIMAGEMASK;
tvi.state = 0;
SendMessage(tvw.Handle, TVM_SETITEM, IntPtr.Zero, ref tvi);
}
All of the messy stuff at the top are your P/Invoke declarations. You need a handful of constants, the TVITEM structure that describes the attributes of a treeview item, and the SendMessage function. At the bottom is the function you'll actually call to do the deed (HideCheckBox). You simply pass in the TreeView control and the particular TreeNode item from which you want to remove the checkmark.
So you can remove the checkmarks from each of the child nodes to get something that looks like this:

Using TreeViewExtensions.
Usage sample:
private void MyForm_Load(object sender, EventArgs e)
{
this.treeview1.DrawMode = TreeViewDrawMode.OwnerDrawText;
this.treeview1.DrawNode += new DrawTreeNodeEventHandler(arbolDependencias_DrawNode);
}
void treeview1_DrawNode(object sender, DrawTreeNodeEventArgs e)
{
if (e.Node.Level == 1) e.Node.HideCheckBox();
e.DrawDefault = true;
}
Here is the answer's code as an Extension method, using this you can do:
public static class TreeViewExtensions
{
private const int TVIF_STATE = 0x8;
private const int TVIS_STATEIMAGEMASK = 0xF000;
private const int TV_FIRST = 0x1100;
private const int TVM_SETITEM = TV_FIRST + 63;
[StructLayout(LayoutKind.Sequential, Pack = 8, CharSet = CharSet.Auto)]
private 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;
}
[DllImport("user32.dll", CharSet = CharSet.Auto)]
private static extern IntPtr SendMessage(IntPtr hWnd, int Msg, IntPtr wParam,
ref TVITEM lParam);
/// <summary>
/// Hides the checkbox for the specified node on a TreeView control.
/// </summary>
public static void HideCheckBox(this TreeNode node)
{
TVITEM tvi = new TVITEM();
tvi.hItem = node.Handle;
tvi.mask = TVIF_STATE;
tvi.stateMask = TVIS_STATEIMAGEMASK;
tvi.state = 0;
SendMessage(node.TreeView.Handle, TVM_SETITEM, IntPtr.Zero, ref tvi);
}
}

This is very good! The only modification I'd make is to pass only the TreeNode and not the TreeView to the HideCheckBox method. The TreeView can be retrieved from the TreeNode itself:
TreeView tvw = node.TreeView;

Related

Prevent AutoSelect behavior of a System.Window.Forms.ComboBox (C#)

Background:
I have a Forms.ComboBox with a DropDownStyle = DropDown.
I don't use AutoComplete, but I implemented something similar which does not only filter the beginning of the text, but uses a regular expression and shows all items which match the text entered. This works fine.
However, when I type the first letter of a matching item, the ComboBox falls back to its original behavior and sets DroppedDown = true and auto selects the first entry and completes the text to match the selected item (similar to AutoCompleteMode Append). What I want is no auto selection and auto completion.
What I found so far is, that I somehow have to prevent SendMessage() with CB_FINDSTRING of being called and replace CB_FINDSTRING with CB_FINDSTRINGEXACT (MSDN Link).
I think I have to extend the ComboBox class, but I'm not sure which methods I have to override. I'm working with C# .NET Framework v3.5.
Questions:
How do I extend a Windows.Forms.ComboBox to prevent the auto select behavior?
Links:
How can I prevent auto-select in ComboBox on drop-down except for exact matches? (did not help me)
Try this:
using System;
using System.Collections.Generic;
using System.Runtime.InteropServices;
using System.Windows.Forms;
using Opulos.Core.Win32;
namespace Opulos.Core.UI {
// Extension class to disable the auto-select behavior when a combobox is in DropDown mode.
public static class ComboBoxAutoSelectEx {
public static void AutoSelectOff(this ComboBox combo) {
Data.Register(combo);
}
public static void AutoSelectOn(this ComboBox combo) {
Data data = null;
if (Data.dict.TryGetValue(combo, out data)) {
data.Dispose();
Data.dict.Remove(combo);
}
}
private class Data {
// keep a reference to the native windows so they don't get disposed
internal static Dictionary<ComboBox, Data> dict = new Dictionary<ComboBox, Data>();
// a ComboBox consists of 3 windows (combobox handle, text edit handle and dropdown list handle)
ComboBox combo;
NW nwList = null; // handle to the combobox's dropdown list
NW2 nwEdit = null; // handle to the edit window
internal void Dispose() {
dict.Remove(this.combo);
this.nwList.ReleaseHandle();
this.nwEdit.ReleaseHandle();
}
public static void Register(ComboBox combo) {
if (dict.ContainsKey(combo))
return; // already registered
Data data = new Data() { combo = combo };
Action assign = () => {
if (dict.ContainsKey(combo))
return; // already assigned
COMBOBOXINFO info = COMBOBOXINFO.GetInfo(combo); // new COMBOBOXINFO();
//info.cbSize = Marshal.SizeOf(info);
//COMBOBOXINFO2.SendMessageCb(combo.Handle, 0x164, IntPtr.Zero, out info);
dict[combo] = data;
data.nwList = new NW(combo, info.hwndList);
data.nwEdit = new NW2(info.hwndEdit);
};
if (!combo.IsHandleCreated)
combo.HandleCreated += delegate { assign(); };
else
assign();
combo.HandleDestroyed += delegate {
data.Dispose();
};
}
}
private class NW : NativeWindow {
ComboBox combo;
public NW(ComboBox combo, IntPtr handle) {
this.combo = combo;
AssignHandle(handle);
}
private const int LB_FINDSTRING = 0x018F;
private const int LB_FINDSTRINGEXACT = 0x01A2;
protected override void WndProc(ref Message m) {
if (m.Msg == LB_FINDSTRING) {
m.Msg = LB_FINDSTRINGEXACT;
}
base.WndProc(ref m);
if (m.Msg == LB_FINDSTRINGEXACT) {
String find = Marshal.PtrToStringAuto(m.LParam);
for (int i = 0; i < combo.Items.Count; i++) {
Object item = combo.Items[i];
if (item.Equals(find)) {
m.Result = new IntPtr(i);
break;
}
}
}
}
}
private class NW2 : NativeWindow {
public NW2(IntPtr handle) {
AssignHandle(handle);
}
private const int EM_SETSEL = 0x00B1;
private const int EM_GETSEL = 0x00B0;
protected override void WndProc(ref Message m) {
if (m.Msg == EM_SETSEL) {
// if this code is not here, then the entire combobox text is selected
// which looks ugly, especially when there are multiple combo boxes.
//
// if this method returns immediately, then the caret position is set
// to (0, 0). However, it seems that calling EM_GETSEL has a side effect
// that the caret position is mostly maintained. Sometimes it slips back
// to (0, 0).
SendMessage(Handle, EM_GETSEL, IntPtr.Zero, IntPtr.Zero);
//int selStart = (sel & 0x00ff);
//int selEnd = (sel >> 16) & 0x00ff;
//Debug.WriteLine("EM_GETSEL: " + selStart + " nEnd: " + selEnd);
return;
}
base.WndProc(ref m);
}
[DllImportAttribute("user32.dll", SetLastError=true)]
private static extern int SendMessage(IntPtr hWnd, int msg, IntPtr wParam, IntPtr lParam);
}
}
[StructLayout(LayoutKind.Sequential)]
public struct COMBOBOXINFO {
public Int32 cbSize;
public RECT rcItem;
public RECT rcButton;
public int buttonState;
public IntPtr hwndCombo;
public IntPtr hwndEdit;
public IntPtr hwndList;
public static COMBOBOXINFO GetInfo(ComboBox combo) {
COMBOBOXINFO info = new COMBOBOXINFO();
info.cbSize = Marshal.SizeOf(info);
SendMessageCb(combo.Handle, 0x164, IntPtr.Zero, out info);
return info;
}
[DllImport("user32.dll", EntryPoint = "SendMessageW", CharSet = CharSet.Unicode)]
private static extern IntPtr SendMessageCb(IntPtr hWnd, int msg, IntPtr wp, out COMBOBOXINFO lp);
}
//[StructLayout(LayoutKind.Sequential)]
//public struct RECT {
// public int Left;
// public int Top;
// public int Right;
// public int Bottom;
//}
}

How to modify the default size of System.Windows.Forms.FolderBrowserDialog? It's too small if you don't modify it by hand

I want the FolderBrowserDialog to be larger when first shown so that it can show more than three-level directory. Is that anyway to do it or is there anyway to override a similiar dialog?
I shamelessly copied Hans's code and modified it to achieve what you want.
private void button1_Click(object sender, EventArgs e)
{
using (new SizeWinDialog(this)//This refers to wpf Window
{
PreferredSize = new Size(150, 150)//Change this size to whatever you want
})
{
FolderBrowserDialog fbd = new FolderBrowserDialog();
fbd.ShowDialog();
}
}
class SizeWinDialog : IDisposable
{
private int mTries = 0;
private Window mOwner;
public SizeWinDialog(Window owner)
{
mOwner = owner;
owner.Dispatcher.BeginInvoke(new Action(findDialog));
}
public Size PreferredSize { get; set; }
private void findDialog()
{
// Enumerate windows to find the message box
if (mTries < 0) return;
EnumThreadWndProc callback = new EnumThreadWndProc(checkWindow);
if (EnumThreadWindows(GetCurrentThreadId(), callback, IntPtr.Zero))
{
if (++mTries < 10) mOwner.Dispatcher.BeginInvoke(new MethodInvoker(findDialog));
}
}
private bool checkWindow(IntPtr hWnd, IntPtr lp)
{
// Checks if <hWnd> is a dialog
StringBuilder sb = new StringBuilder(260);
GetClassName(hWnd, sb, sb.Capacity);
if (sb.ToString() != "#32770") return true;
// Got it
RECT dlgRect;
GetWindowRect(hWnd, out dlgRect);
SetWindowPos(new HandleRef(this, hWnd), new HandleRef(), dlgRect.Left, dlgRect.Top, PreferredSize.Width, PreferredSize.Height, 20 | 2);
return false;
}
public void Dispose()
{
mTries = -1;
}
// P/Invoke declarations
private delegate bool EnumThreadWndProc(IntPtr hWnd, IntPtr lp);
[DllImport("user32.dll")]
private static extern bool EnumThreadWindows(int tid, EnumThreadWndProc callback, IntPtr lp);
[DllImport("kernel32.dll")]
private static extern int GetCurrentThreadId();
[DllImport("user32.dll")]
private static extern int GetClassName(IntPtr hWnd, StringBuilder buffer, int buflen);
[DllImport("user32.dll")]
private static extern bool GetWindowRect(IntPtr hWnd, out RECT rc);
[DllImport("user32.dll", CharSet = CharSet.Auto, ExactSpelling = true)]
public static extern bool SetWindowPos(HandleRef hWnd, HandleRef hWndInsertAfter, int x, int y, int cx, int cy,
int flags);
private struct RECT { public int Left; public int Top; public int Right; public int Bottom; }
}
I converted the code sample above back to WinForms from the WPF version that is shown. I also created two companion classes that will size a system dialog and will place it at a specific offset from the parent form. They are used like this:
using (new OffsetWinDialog(this) { PreferredOffset = new Point(75, 75 )})
using (new SizeWinDialog(this) { PreferredSize = new Size(400, 600)})
{
DialogResult result = dlgFolderBrowser.ShowDialog();
if (result == DialogResult.Cancel)
return;
}
The original post (below) shows how to place the system dialog at the center of the parent. Together, these three classes will let you control the initial size and position of the system dialogs. Rather than repeat the code here, please refer to the following thread.
Winforms-How can I make MessageBox appear centered on MainForm?

Drawing a circle outside the Winform

I am creating a Screen Recording app using Windows media encoder, i Can record the video and save it to a disk,now i need to draw a filled circle around the mouse click area when ever the mouse click event Fire( to high light the area that mouse press event occur), is there a way to do that? any code sample? thank you!!! sorry for not inserting the code here is my code
public void CaptureMoni()
{
string dateTime = DateTime.Now.ToString("yyyy.MM.dd _ HH.mm");
var dir = #"C:\VIDEOS\" + dateTime;
try
{
System.Drawing.Rectangle _screenRectangle = Screen.PrimaryScreen.Bounds;
_screenCaptureJob = new ScreenCaptureJob();
_screenCaptureJob.CaptureRectangle = _screenRectangle;
_screenCaptureJob.ShowFlashingBoundary = true;
_screenCaptureJob.ScreenCaptureVideoProfile.FrameRate = 10;
_screenCaptureJob.CaptureMouseCursor = true;
if (!Directory.Exists(dir))
{
Directory.CreateDirectory(dir);
_screenCaptureJob.OutputScreenCaptureFileName = string.Format(Path.Combine(dir, dateTime + ".wmv"));
}
}
catch (Exception)
{
MessageBox.Show("Screnn Capturing Failed!" );
}
string temPath = (_screenCaptureJob.OutputScreenCaptureFileName.ToString());
// MessageBox.Show(temPath);
}
public ScreenCaptureJob _screenCaptureJob { get; set; }
finally i did what i need Special thanks to PacMani he direct me the right way,
NOTE : this is not a full code which include red circle in the video, this is only for having a red circle and making the transparent form on top of the all the other forms (sorry for the language mistakes)) thank you for the Help # PacMAni
public partial class Form1 : Form
{
public Form1()
{
InitializeComponent();
WindowState = FormWindowState.Maximized;
this.TopMost = true;
}
protected override void WndProc(ref Message m)
{
if (m.Msg == (int)RMouseListener.WM.WM_NCHITTEST)
m.Result = (IntPtr)RMouseListener.WM.HTTRANSPARENT;
else
base.WndProc(ref m);
}
public void draw_circle()
{
int x = MousePosition.X;
int y = MousePosition.Y;
System.Drawing.SolidBrush myBrush = new System.Drawing.SolidBrush(System.Drawing.Color.Salmon);
System.Drawing.Graphics formGraphics = this.CreateGraphics();
formGraphics.FillEllipse(myBrush, new Rectangle(x - 60, y - 60, 60, 60));
myBrush.Dispose();
formGraphics.Dispose();
Thread.Sleep(200);
this.Invalidate();
}
RMouseListener _native;
private void button1_Click(object sender, EventArgs e)
{
//_native = new RMouseListener();
//_native.RButtonClicked += new EventHandler<SysMouseEventInfo>(_native_RButtonClicked);
//_native.LButtonClicked += new EventHandler<SysMouseEventInfo>(_native_LButtonClicked);
}
private void button2_Click(object sender, EventArgs e)
{
_native.Close();
this.Dispose();
}
void _native_RButtonClicked(object sender, SysMouseEventInfo e)
{
// listBox1.Items.Add(e.WindowTitle);
draw_circle();
}
void _native_LButtonClicked(object sender, SysMouseEventInfo e)
{
// listBox2.Items.Add(e.WindowTitle);
draw_circle();
}
// }
public class SysMouseEventInfo : EventArgs
{
public string WindowTitle { get; set; }
}
public class RMouseListener
{
Form1 frm = new Form1();
public RMouseListener()
{
this.CallBack += new HookProc(MouseEvents);
//Module mod = Assembly.GetExecutingAssembly().GetModules()[0];
//IntPtr hMod = Marshal.GetHINSTANCE(mod);
using (Process process = Process.GetCurrentProcess())
using (ProcessModule module = process.MainModule)
{
IntPtr hModule = GetModuleHandle(module.ModuleName);
_hook = SetWindowsHookEx(WH_MOUSE_LL, this.CallBack, hModule, 0);
}
}
int WH_MOUSE_LL = 14;
int HC_ACTION = 0;
HookProc CallBack = null;
IntPtr _hook = IntPtr.Zero;
public event EventHandler<SysMouseEventInfo> RButtonClicked;
public event EventHandler<SysMouseEventInfo> LButtonClicked;
int MouseEvents(int code, IntPtr wParam, IntPtr lParam)
{
//Console.WriteLine("Called");
//MessageBox.Show("Called!");
if (code < 0)
return CallNextHookEx(_hook, code, wParam, lParam);
if (code == this.HC_ACTION)
{
// Left button pressed somewhere
if (wParam.ToInt32() == (uint)WM.WM_RBUTTONDOWN || wParam.ToInt32() == (uint)WM.WM_LBUTTONDOWN)
{
MSLLHOOKSTRUCT ms = new MSLLHOOKSTRUCT();
ms = (MSLLHOOKSTRUCT)Marshal.PtrToStructure(lParam, typeof(MSLLHOOKSTRUCT));
IntPtr win = WindowFromPoint(ms.pt);
string title = GetWindowTextRaw(win);
if (RButtonClicked != null || LButtonClicked != null)
{
RButtonClicked(this, new SysMouseEventInfo { WindowTitle = title });
LButtonClicked(this, new SysMouseEventInfo { WindowTitle = title });
}
}
}
return CallNextHookEx(_hook, code, wParam, lParam);
}
public void Close()
{
if (_hook != IntPtr.Zero)
{
UnhookWindowsHookEx(_hook);
}
}
public delegate int HookProc(int code, IntPtr wParam, IntPtr lParam);
[System.Runtime.InteropServices.DllImport("user32.dll", EntryPoint = "SetWindowsHookEx", SetLastError = true)]
public static extern IntPtr SetWindowsHookEx(int idHook, HookProc lpfn, IntPtr hMod, uint dwThreadId);
[System.Runtime.InteropServices.DllImport("user32.dll")]
public static extern int CallNextHookEx(IntPtr hhk, int nCode, IntPtr wParam, IntPtr lParam);
[System.Runtime.InteropServices.DllImport("kernel32.dll", CharSet = System.Runtime.InteropServices.CharSet.Auto)]
public static extern IntPtr GetModuleHandle(string lpModuleName);
[DllImport("user32.dll")]
static extern IntPtr WindowFromPoint(int xPoint, int yPoint);
[DllImport("user32.dll")]
static extern IntPtr WindowFromPoint(POINT Point);
[DllImport("user32.dll", SetLastError = true)]
[return: MarshalAs(UnmanagedType.Bool)]
static extern bool UnhookWindowsHookEx(IntPtr hhk);
[DllImport("user32.dll", CharSet = CharSet.Auto)]
static extern IntPtr SendMessage(IntPtr hWnd, UInt32 Msg, IntPtr wParam, [Out] StringBuilder lParam);
public static string GetWindowTextRaw(IntPtr hwnd)
{
// Allocate correct string length first
//int length = (int)SendMessage(hwnd, (int)WM.WM_GETTEXTLENGTH, IntPtr.Zero, IntPtr.Zero);
StringBuilder sb = new StringBuilder(65535);//THIS COULD BE BAD. Maybe you shoudl get the length
SendMessage(hwnd, (int)WM.WM_GETTEXT, (IntPtr)sb.Capacity, sb);
return sb.ToString();
}
[StructLayout(LayoutKind.Sequential)]
public struct MSLLHOOKSTRUCT
{
public POINT pt;
public int mouseData;
public int flags;
public int time;
public UIntPtr dwExtraInfo;
}
public enum WM : uint
{//all windows messages here
WM_LBUTTONDOWN = 0x0201,
WM_RBUTTONDOWN = 0x0204,
WM_GETTEXT = 0x000D,
WM_GETTEXTLENGTH = 0x000E,
WM_MOUSE = 0x0200,
WM_NCHITTEST = 0x84,
HTTRANSPARENT
}
[StructLayout(LayoutKind.Sequential)]
public struct POINT
{
public int X;
public int Y;
public POINT(int x, int y)
{
this.X = x;
this.Y = y;
}
}
}
private void Form1_Load(object sender, EventArgs e)
{
_native = new RMouseListener();
_native.RButtonClicked += new EventHandler<SysMouseEventInfo>(_native_RButtonClicked);
_native.LButtonClicked += new EventHandler<SysMouseEventInfo>(_native_LButtonClicked);
}
Screen recording applications add this circle in their video file, not on the desktop.
If you still want to create a circle window, you need a form with the two things you have to implement:
Click-through window (otherwise the cursor could not click on things behind it anymore). See here for the solution: Click through transparency for Visual C# Window Forms?
Transparent window (transparency key might be enough here already, if you want alpha-blended transparency, things get more exciting, there are many examples for that on CodeProject, for example http://www.codeproject.com/Articles/20758/Alpha-Blended-Windows-Forms). Without this, you would have a rectangular window and not just a circle.
Also you need to register a global mouse hook to detect global mouse clicks. I think you already did this, but your question does not show what you've done and what not.
If you received a mouse click, create a borderless window around the mouse coordinates and (with the background color being the same as the transparency key to make it invisible where the circle isn't drawn) draw an ellipse on it (hook the Paint-event and use the Graphics objects DrawEllipse method).
Start a timer after which this window disappears again (or the circle would be visible forever). If you want this circle to animate as in other screen recording apps, use the timer to animate the drawing.

Application stuck in full screen?

To reproduce my problem please do the following:
Create a new Windows Form Application in C#.
In the Properties window of Form1 set FormBorderStyle to None.
Launch program and press Windows+Up.
Now you are stuck in full screen.
In the default FormBorderStyle setting the MaximizeBox property to false will disable the Windows+Up fullscreen shortcut.
If the FormBorderStyle is set to None Microsoft decided it would be a good idea to disable all the Windows+Arrow key shortcuts except for the up arrow and then disable the disabling of the MaximizeBox property.
Is this a glitch? Any simple way to disable this shortcut function the selfsame way it is disabled on all the other FormBorderStyles?
Windows does this by calling SetWindowPos() to change the position and size of the window. A window can be notified about this by listening for the WM_WINDOWPOSCHANGING message and override the settings. Lots of things you can do, like still giving the operation a meaning by adjusting the size and position to your liking. You completely prevent it by turning on the NOSIZE and NOMOVE flags.
Paste this code into your form:
private bool AllowWindowChange;
private struct WINDOWPOS {
public IntPtr hwnd, hwndInsertAfter;
public int x, y, cx, cy;
public int flags;
}
protected override void WndProc(ref Message m) {
// Trap WM_WINDOWPOSCHANGING
if (m.Msg == 0x46 && !AllowWindowChange) {
var wpos = (WINDOWPOS)System.Runtime.InteropServices.Marshal.PtrToStructure(m.LParam, typeof(WINDOWPOS));
wpos.flags |= 0x03; // Turn on SWP_NOSIZE | SWP_NOMOVE
System.Runtime.InteropServices.Marshal.StructureToPtr(wpos, m.LParam, false);
}
base.WndProc(ref m);
}
When you want to change the window yourself, simply set the AllowWindowChange field temporarily to true.
Trap the WM_GETMINMAXINFO message which will allow you to specify the maximized size and location of your form. Technically your form will still change state to Maximized, but it will appear the same since we specify the maximized size/position to be the same as the normal state of the form:
public partial class Form1 : Form
{
public Form1()
{
InitializeComponent();
}
public struct POINTAPI
{
public Int32 X;
public Int32 Y;
}
public struct MINMAXINFO
{
public POINTAPI ptReserved;
public POINTAPI ptMaxSize;
public POINTAPI ptMaxPosition;
public POINTAPI ptMinTrackSize;
public POINTAPI ptMaxTrackSize;
}
public const Int32 WM_GETMINMAXINFO = 0x24;
protected override void WndProc(ref Message m)
{
switch (m.Msg)
{
case WM_GETMINMAXINFO:
MINMAXINFO mmi = (MINMAXINFO)System.Runtime.InteropServices.Marshal.PtrToStructure(m.LParam, typeof(MINMAXINFO));
mmi.ptMaxSize.X = this.Width;
mmi.ptMaxSize.Y = this.Height;
mmi.ptMaxPosition.X = this.Location.X;
mmi.ptMaxPosition.Y = this.Location.Y;
System.Runtime.InteropServices.Marshal.StructureToPtr(mmi, m.LParam, true);
break;
}
base.WndProc(ref m);
}
}
Overriding the ProcessCmdKey (protected method in Form) explicitly allow us to apply custom hook and can be used in your scenario. This essentially allow us to override built-in keystroke handling.
Note: Following example demonstrate the idea of how to handle different keystroke or combination of it. Now, you probably need to fine tune the following code to work inline with your scenario. Eg: Ideally changing the FormBorderStyle or Form Size when user press the LWin+Up arrow.
public partial class Form1 : Form
{
protected override bool ProcessCmdKey(ref Message msg, Keys keyData)
{
if (keyData == (Keys.LWin | Keys.Up))//Left windows key + up arrow
{
FormBorderStyle = FormBorderStyle.FixedDialog;
return true;
}
if (keyData == Keys.Escape) //Form will call its close method when we click Escape.
Close();
return base.ProcessCmdKey(ref msg, keyData);
}
}
Updated on How to disable windows Key in your case Lwin or RWin
public partial class Form1 : Form
{
// 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;
public Form1()
{
ProcessModule objCurrentModule = Process.GetCurrentProcess().MainModule;
objKeyboardProcess = new LowLevelKeyboardProc(captureKey);
ptrHook = SetWindowsHookEx(13, objKeyboardProcess, GetModuleHandle(objCurrentModule.ModuleName), 0);
InitializeComponent();
}
private IntPtr captureKey(int nCode, IntPtr wp, IntPtr lp)
{
if (nCode >= 0)
{
KBDLLHOOKSTRUCT objKeyInfo = (KBDLLHOOKSTRUCT)Marshal.PtrToStructure(lp, typeof(KBDLLHOOKSTRUCT));
if (objKeyInfo.key == Keys.RWin || objKeyInfo.key == Keys.LWin) // Disabling Windows keys
{
return (IntPtr)1;
}
}
return CallNextHookEx(ptrHook, nCode, wp, lp);
}
private void Form1_KeyPress(object sender, KeyPressEventArgs e)
{
MessageBox.Show(e.KeyChar.ToString());
}
}
Check this solution - it removes Maximize/Minimize/Titlebar/Border by API calls.
public partial class Form1 : Form
{
// import necessary API functions to get and set Windows styles for P/Invoke
[DllImport("user32.dll")]
internal extern static int SetWindowLong(IntPtr hwnd, int index, int value);
[DllImport("user32.dll")]
internal extern static int GetWindowLong(IntPtr hwnd, int index);
// define constants like they are named in SDK in order to make source more readable
const int GWL_STYLE = -16;
const int GWL_EXSTYLE = -20;
const int WS_MINIMIZEBOX = 0x00020000;
const int WS_MAXIMIZEBOX = 0x00010000;
const int WS_CAPTION = 0x00C00000;
const int WS_THICKFRAME = 0x00040000;
const int WS_EX_DLGMODALFRAME = 0x00000001;
const int WS_EX_CLIENTEDGE = 0x00000200;
const int WS_EX_STATICEDGE = 0x00020000;
// this replaces MinimizeBox=false and MaximizeBox=false
void HideMinimizeAndMaximizeButtons()
{
// read current style
int style = GetWindowLong(Handle, GWL_STYLE);
Debug.WriteLine("0x{0:X}", style);
// update style - remove flags for MinimizeBox and MaximizeBox
style = style & ~WS_MINIMIZEBOX & ~WS_MAXIMIZEBOX;
Debug.WriteLine("0x{0:X}", style);
SetWindowLong(Handle, GWL_STYLE, style);
}
// part of removing the whole border
void HideTitleBar()
{
// read current style
int style = GetWindowLong(Handle, GWL_STYLE);
Debug.WriteLine("0x{0:X}", style);
// update style - remove flag for caption
style = style & ~WS_CAPTION;
Debug.WriteLine("0x{0:X}", style);
SetWindowLong(Handle, GWL_STYLE, style);
}
// hide the border
void HideBorder()
{
// read current style
int style = GetWindowLong(Handle, GWL_STYLE);
Debug.WriteLine("0x{0:X}", style);
// update style - remove flag for border (could use WS_SIZEBOX which is the very same flag (see MSDN)
style = style & ~WS_THICKFRAME;
Debug.WriteLine("0x{0:X}", style);
SetWindowLong(Handle, GWL_STYLE, style);
// read current extended style
style = GetWindowLong(Handle, GWL_EXSTYLE);
Debug.WriteLine("0x{0:X}", style);
// update style by removing some additional border styles -
// may not be necessary, when current border style is not something exotic,
// i.e. as long as it "normal"
style = style & ~WS_EX_DLGMODALFRAME & ~WS_EX_CLIENTEDGE & ~WS_EX_STATICEDGE;
Debug.WriteLine("0x{0:X}", style);
SetWindowLong(Handle, GWL_EXSTYLE, style);
}
public Form1()
{
InitializeComponent();
// hide those unwanted properties - you can try to leave out one or another to see what it does
HideMinimizeAndMaximizeButtons();
HideTitleBar();
HideBorder();
}
}
This works as intended. Maximizing/minimizing by setting WindowState works as well.
One could analyze in sources what the framework does and what it does "wrong" (or not quite correct).
Edit: I added debug output of the style values. Please try this sequence of commands in Form1 constructor:
MaximizeBox = false;
FormBorderStyle = FormBorderStyle.Sizable;
HideMinimizeAndMaximizeButtons();
FormBorderStyle = FormBorderStyle.None;
MaximizeBox = true;
MaximizeBox = false;
HideMinimizeAndMaximizeButtons();
FormBorderStyle = FormBorderStyle.None;
HideMinimizeAndMaximizeButtons();
You'll see, that setting FormBorderStyle.None enables the WS_MAXIMIZEBOX style. This cannot be "corrected" by another MaximizeBox = false. It seems it's necessary to call API functions.

Combo box drop down width on suggest

I have a form which has a Combo Box Control. I have selected the drop down style property to DropDown. I have also set the DropDown Width to 250. I have set the auto complete mode to suggest and the auto complete source to listitems. it works absolutely fine when i click on the drop down. but when i type in somethin, the auto complete mode activates a drop down which has a small width.
any help appreciate. i wanna know how to increase the width of the auto complete drop down via code so that the list items are viewed properly. I am using C#.
I had asked this a couple of months back but didn't get a proper answer. now the customer wants it bad :(
??
using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Drawing;
using System.Runtime.InteropServices;
using System.Text;
using System.Windows.Forms;
/// <summary>
/// Represents an ComboBox with additional properties for setting the
/// size of the AutoComplete Drop-Down window.
/// </summary>
public class ComboBoxEx : ComboBox
{
private int acDropDownHeight = 106;
private int acDropDownWidth = 170;
//<EditorBrowsable(EditorBrowsableState.Always), _
[Browsable(true), Description("The width, in pixels, of the auto complete drop down box"), DefaultValue(170)]
public int AutoCompleteDropDownWidth
{
get { return acDropDownWidth; }
set { acDropDownWidth = value; }
}
//<EditorBrowsable(EditorBrowsableState.Always), _
[Browsable(true), Description("The height, in pixels, of the auto complete drop down box"), DefaultValue(106)]
public int AutoCompleteDropDownHeight
{
get { return acDropDownHeight; }
set { acDropDownHeight = value; }
}
protected override void OnHandleCreated(EventArgs e)
{
base.OnHandleCreated(e);
ACWindow.RegisterOwner(this);
}
#region Nested type: ACWindow
/// <summary>
/// Provides an encapsulation of an Auto complete drop down window
/// handle and window proc.
/// </summary>
private class ACWindow : NativeWindow
{
private static readonly Dictionary<IntPtr, ACWindow> ACWindows;
#region "Win API Declarations"
private const UInt32 WM_WINDOWPOSCHANGED = 0x47;
private const UInt32 WM_NCDESTROY = 0x82;
private const UInt32 SWP_NOSIZE = 0x1;
private const UInt32 SWP_NOMOVE = 0x2;
private const UInt32 SWP_NOZORDER = 0x4;
private const UInt32 SWP_NOREDRAW = 0x8;
private const UInt32 SWP_NOACTIVATE = 0x10;
private const UInt32 GA_ROOT = 2;
private static readonly List<ComboBoxEx> owners;
[DllImport("user32.dll")]
private static extern bool EnumThreadWindows(int dwThreadId, EnumThreadDelegate lpfn, IntPtr lParam);
[DllImport("user32.dll")]
private static extern IntPtr GetAncestor(IntPtr hWnd, UInt32 gaFlags);
[DllImport("kernel32.dll")]
private static extern int GetCurrentThreadId();
[DllImport("user32.dll")]
private static extern void GetClassName(IntPtr hWnd, StringBuilder lpClassName, int nMaxCount);
[DllImport("user32.dll")]
private static extern bool SetWindowPos(IntPtr hWnd, IntPtr hWndInsertAfter, int X, int Y, int cx, int cy,
uint uFlags);
[DllImport("user32.dll")]
private static extern bool GetWindowRect(IntPtr hWnd, ref RECT lpRect);
#region Nested type: EnumThreadDelegate
private delegate bool EnumThreadDelegate(IntPtr hWnd, IntPtr lParam);
#endregion
#region Nested type: RECT
[StructLayout(LayoutKind.Sequential)]
private struct RECT
{
public readonly int Left;
public readonly int Top;
public readonly int Right;
public readonly int Bottom;
public Point Location
{
get { return new Point(Left, Top); }
}
}
#endregion
#endregion
private ComboBoxEx owner;
static ACWindow()
{
ACWindows = new Dictionary<IntPtr, ACWindow>();
owners = new List<ComboBoxEx>();
}
/// <summary>
/// Creates a new ACWindow instance from a specific window handle.
/// </summary>
private ACWindow(IntPtr handle)
{
AssignHandle(handle);
}
/// <summary>
/// Registers a ComboBoxEx for adjusting the Complete Dropdown window size.
/// </summary>
public static void RegisterOwner(ComboBoxEx owner)
{
if ((owners.Contains(owner)))
{
return;
}
owners.Add(owner);
EnumThreadWindows(GetCurrentThreadId(), EnumThreadWindowCallback, IntPtr.Zero);
}
/// <summary>
/// This callback will receive the handle for each window that is
/// associated with the current thread. Here we match the drop down window name
/// to the drop down window name and assign the top window to the collection
/// of auto complete windows.
/// </summary>
private static bool EnumThreadWindowCallback(IntPtr hWnd, IntPtr lParam)
{
if ((GetClassName(hWnd) == "Auto-Suggest Dropdown"))
{
IntPtr handle = GetAncestor(hWnd, GA_ROOT);
if ((!ACWindows.ContainsKey(handle)))
{
ACWindows.Add(handle, new ACWindow(handle));
}
}
return true;
}
/// <summary>
/// Gets the class name for a specific window handle.
/// </summary>
private static string GetClassName(IntPtr hRef)
{
var lpClassName = new StringBuilder(256);
GetClassName(hRef, lpClassName, 256);
return lpClassName.ToString();
}
/// <summary>
/// Overrides the NativeWindow's WndProc to handle when the window
/// attributes changes.
/// </summary>
protected override void WndProc(ref Message m)
{
if ((m.Msg == WM_WINDOWPOSCHANGED))
{
// If the owner has not been set we need to find the ComboBoxEx that
// is associated with this dropdown window. We do it by checking if
// the upper-left location of the drop-down window is within the
// ComboxEx client rectangle.
if ((owner == null))
{
Rectangle ownerRect = default(Rectangle);
var acRect = new RECT();
foreach (ComboBoxEx cbo in owners)
{
GetWindowRect(Handle, ref acRect);
ownerRect = cbo.RectangleToScreen(cbo.ClientRectangle);
if ((ownerRect.Contains(acRect.Location)))
{
owner = cbo;
break; // TODO: might not be correct. Was : Exit For
}
}
owners.Remove(owner);
}
if (((owner != null)))
{
SetWindowPos(Handle, IntPtr.Zero, -5, 0, owner.AutoCompleteDropDownWidth,
owner.AutoCompleteDropDownHeight, SWP_NOMOVE | SWP_NOZORDER | SWP_NOACTIVATE);
}
}
if ((m.Msg == WM_NCDESTROY))
{
ACWindows.Remove(Handle);
}
base.WndProc(ref m);
}
}
#endregion
}
This is what I did and it actually works really well. Good to find an answer atlast :)
This answer is an addition to reggie's answer.
If you want the user to be able to resize the auto-complete dropdown, then add the following code inside the WndProc method:
private const int WM_SIZING = 0x214;
if (m.Msg == WM_SIZING) {
if (owner != null) {
RECT rr = (RECT) Marshal.PtrToStructure(m.LParam, typeof(RECT));
owner.acDropDownWidth = (rr.Right - rr.Left);
owner.acDropDownHeight = (rr.Bottom - rr.Top);
}
}
kind of a bad design decision to do that. Why not set it to a static large size to start with? You can always use one of the events to get the text width and then use that to set the combobox width. Possibly the onPaint? easier way might be to create your own combobox class that inherits from combo box and then override the methods to do this yourself.

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