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ComboBox Text Align Vertically Center

I created the custom combobox on .net framework 1.1, i can custom draw dropdown items, but i can't set or draw the combobox text on Middle Left , combobox text always render top left , but i need text should be render on middle left.
[ToolboxBitmap(typeof(ComboBox))]
public class MenComboBox :ComboBox
{
private Image _image = Image.FromFile("Expand.png");
public MenComboBox()
{
this.DrawMode = DrawMode.OwnerDrawFixed;
this.BackColor = Color.White;
this.ItemHeight = 18;
this.Font = new Font("Arial",12f,FontStyle.Regular);
}
protected override void OnDrawItem(DrawItemEventArgs e)
{
if (!DesignMode)
{
if (e.Index > -1)
{
int textHeight = (int)e.Graphics.MeasureString(this.Items[e.Index].ToString(), e.Font).Height;
Point textPos = new Point(e.Bounds.X + 4, e.Bounds.Y + ((this.ItemHeight - textHeight) / 2));
if ((e.State & DrawItemState.Selected) == DrawItemState.Selected)
{
e.Graphics.FillRectangle(Brushes.Blue, e.Bounds);
e.Graphics.DrawString(this.Items[e.Index].ToString(),e.Font,Brushes.White,textPos);
}
else
{
e.Graphics.FillRectangle(Brushes.White, e.Bounds);
e.Graphics.DrawString(this.Items[e.Index].ToString(),e.Font,Brushes.Black,textPos);
}
}
}
}
protected override void WndProc(ref Message m)
{
base.WndProc(ref m);
if (m.Msg == 0x000F)
{
using (Graphics g = this.CreateGraphics())
{
g.FillRectangle(new SolidBrush(BackColor), this.ClientRectangle);
g.DrawRectangle(Pens.Blue, new Rectangle(this.ClientRectangle.X, this.ClientRectangle.Y, this.ClientRectangle.Width - 1, this.ClientRectangle.Height - 1));
Rectangle rect = new Rectangle(this.Width - 15, 3, 12, this.Height - 6);
g.FillRectangle(new SolidBrush(BackColor), rect);
g.DrawImage(this._image, this.Width - 16, (this.Height - 8) / 2);
g.Dispose();
}
}
}
}

In an owner draw ComboBox the text of the Edit part of the control will always be shown at top left, regardless of the height of the ItemHeight.
To position the Edit part vertically in middle, you can find the Edit element using GetComboBoxInfo and then using SetWindowPos set a new position for it to stand vertically in middle of the ComboBox.
You need to reposition it when the control size changes. Also you need to fill the background of ComboBox with a Color.
Here is the code that I used:
using System;
using System.Drawing;
using System.Runtime.InteropServices;
using System.Windows.Forms;
public class MyComboBox : ComboBox
{
public MyComboBox()
{
SetStyle(ControlStyles.ResizeRedraw, true);
DrawMode = DrawMode.OwnerDrawFixed;
ItemHeight = 40;
}
[StructLayout(LayoutKind.Sequential)]
public struct RECT
{
public int Left;
public int Top;
public int Right;
public int Bottom;
public int Width { get { return Right - Left; } }
public int Height { get { return Bottom - Top; } }
}
private const int SWP_NOSIZE = 0x0001;
private const int SWP_NOZORDER = 0x0004;
private const int SWP_SHOWWINDOW = 0x0040;
[DllImport("user32.dll", SetLastError = true)]
static extern bool SetWindowPos(IntPtr hWnd, IntPtr hWndInsertAfter,
int X, int Y, int cx, int cy, int uFlags);
[DllImport("user32.dll")]
public static extern bool GetComboBoxInfo(IntPtr hWnd, ref COMBOBOXINFO pcbi);
[StructLayout(LayoutKind.Sequential)]
public struct COMBOBOXINFO
{
public int cbSize;
public RECT rcItem;
public RECT rcButton;
public int stateButton;
public IntPtr hwndCombo;
public IntPtr hwndEdit;
public IntPtr hwndList;
}
protected override void OnResize(EventArgs e)
{
base.OnResize(e);
SetupEdit();
Invalidate();
}
private int buttonWidth = SystemInformation.HorizontalScrollBarArrowWidth;
protected override void WndProc(ref Message m)
{
if (m.Msg == 0xF)
{
using (var g = this.CreateGraphics())
{
var r = new Rectangle(2, 2,
ClientRectangle.Width - buttonWidth - 2,
ClientRectangle.Height - 4);
g.FillRectangle(Brushes.White, r);
}
}
base.WndProc(ref m);
}
protected override void OnVisibleChanged(EventArgs e)
{
base.OnVisibleChanged(e);
SetupEdit();
}
private void SetupEdit()
{
var info = new COMBOBOXINFO();
info.cbSize = Marshal.SizeOf(info);
GetComboBoxInfo(this.Handle, ref info);
SetWindowPos(info.hwndEdit, IntPtr.Zero, 3,
(this.Height - Font.Height) / 2,
ClientRectangle.Width - buttonWidth - 3,
ClientRectangle.Height - Font.Height - 4,
SWP_NOZORDER);
}
protected override void OnDrawItem(DrawItemEventArgs e)
{
base.OnDrawItem(e);
e.DrawBackground();
var txt = "";
if (e.Index >= 0)
txt = GetItemText(Items[e.Index]);
TextRenderer.DrawText(e.Graphics, txt, Font, e.Bounds,
ForeColor, TextFormatFlags.Left | TextFormatFlags.VerticalCenter);
}
}

ok, below code doesn't answer the actual question about the Text portion; Hans got it right, as usual.
I keep the answer because I think it does a few things better than OP code..
if (!DesignMode)
{
if (e.Index > -1)
{
using (StringFormat fmt = new StringFormat()
{ Alignment = StringAlignment.Center, LineAlignment = StringAlignment.Center })
{
if ((e.State & DrawItemState.Selected) == DrawItemState.Selected)
{
e.Graphics.FillRectangle(SystemBrushes.MenuHighlight, e.Bounds);
e.Graphics.DrawString(comboBox1.Items[e.Index].ToString(),
e.Font,SystemBrushes.HighlightText, e.Bounds, fmt);
}
else
{
e.Graphics.FillRectangle(SystemBrushes.Window, e.Bounds);
e.Graphics.DrawString(comboBox1.Items[e.Index].ToString(),
e.Font, SystemBrushes.MenuText,e.Bounds, fmt);
}
}
}
}
Instead of calculating a centered position I use the DrawString overload that takes a target rectangle and add a StringFormat to center in both directions. StringFormat was available since .Net 1.1 and indeed is IDisposable, so we should dipose of each we create, best in a using clause..
Note that for drawing controls the use of TextRenderer is encouraged but only came with .Net 2.0.
Also note that I substituted the Brushes for SystemBrushes..
Also: My ComboBox doesn't place the text in its Text portion top-left but middle-left. Maybe the old .Net1.1 control is the culprit?

How to set the client area (ClientRectangle) in a borderless form?

I want to know if it's possible to set the client area of a borderless form. Say for example I define a form like so:
Code
public class MyForm : Form
{
public MyForm()
{
this.FormBorderStyle = FormBorderStyle.None;
}
}
Result
What I want to do is specify the client area, so that the form has a frame (like the standard windows frame, but custom drawn).
Result
Essentially, the blue area would become the non client area, and the gray area would remain as the client area.
I have tried to set the client area, but this just seems to resize the entire form, thus, is does not leave behind a "non-client" area
Is this possible?

This is possible, however I don't know how well this works with a Windows Form with the WindowStyle set to Borderless. Using PInvoke (Platform Invoke) Functions, you can remove window themes which will give you a very basic looking Windows Form. You can then use various PInvoke functions to manipulate the Non-client area of the windows form.
I recommend that you read through these topics. They're designed for Win32 Applications using C++, but PInvoke is the process of calling these native APIs using Managed Code (C#)
WM_NCCALCSIZE: https://msdn.microsoft.com/en-us/library/windows/desktop/ms632634(v=vs.85).aspx
WM_NCPAINT: https://msdn.microsoft.com/en-us/library/windows/desktop/dd145212(v=vs.85).aspx
GetDCEx: https://msdn.microsoft.com/en-us/library/windows/desktop/dd144873(v=vs.85).aspx
GetWindowDC: https://msdn.microsoft.com/en-us/library/windows/desktop/dd144947(v=vs.85).aspx
SetWindowTheme: https://msdn.microsoft.com/en-us/library/windows/desktop/bb759827(v=vs.85).aspx
This example is very very crude, but it provides basic functionality. I don't know how SetWindowTheme works on Windows 8 or 8.1, but in Windows 7, it gives windows the "classic" theme.
public partial class MyForm : Form
{
//Window Messages
public const uint WM_NCPAINT = 0x85;
public const uint WM_NCCALCSIZE = 0x83;
public const uint WM_NCHITTEST = 0x84;
//GetDCEx Flags
public const int DCX_WINDOW = 0x00000001;
public const int DCX_CACHE = 0x00000002;
public const int DCX_PARENTCLIP = 0x00000020;
public const int DCX_CLIPSIBLINGS = 0x00000010;
public const int DCX_CLIPCHILDREN = 0x00000008;
public const int DCX_NORESETATTRS = 0x00000004;
public const int DCX_LOCKWINDOWUPDATE = 0x00000400;
public const int DCX_EXCLUDERGN = 0x00000040;
public const int DCX_INTERSECTRGN = 0x00000080;
public const int DCX_INTERSECTUPDATE = 0x00000200;
public const int DCX_VALIDATE = 0x00200000;
//RECT Structure
[System.Runtime.InteropServices.StructLayout(System.Runtime.InteropServices.LayoutKind.Sequential)]
public struct RECT
{
public int left, top, right, bottom;
}
//WINDOWPOS Structure
[System.Runtime.InteropServices.StructLayout(System.Runtime.InteropServices.LayoutKind.Sequential)]
public struct WINDOWPOS
{
public IntPtr hwnd;
public IntPtr hwndinsertafter;
public int x, y, cx, cy;
public int flags;
}
//NCCALCSIZE_PARAMS Structure
[System.Runtime.InteropServices.StructLayout(System.Runtime.InteropServices.LayoutKind.Sequential)]
public struct NCCALCSIZE_PARAMS
{
public RECT rgrc0, rgrc1, rgrc2;
public WINDOWPOS lppos;
}
//SetWindowTheme UXtheme Function
[System.Runtime.InteropServices.DllImport("uxtheme.dll", ExactSpelling = true, CharSet = System.Runtime.InteropServices.CharSet.Unicode)]
public static extern int SetWindowTheme(
IntPtr hWnd,
String pszSubAppName,
String pszSubIdList);
//GetWindowRect User32 Function
[System.Runtime.InteropServices.DllImport("user32.dll", ExactSpelling = true)]
[return: System.Runtime.InteropServices.MarshalAs(System.Runtime.InteropServices.UnmanagedType.Bool)]
public static extern bool GetWindowRect(
IntPtr hwnd,
out RECT lpRect
);
//GetWindowDC User32 Function
[System.Runtime.InteropServices.DllImport("user32.dll", ExactSpelling = true)]
public static extern IntPtr GetWindowDC(
IntPtr hWnd
);
//GetDCEx User32 Function
[System.Runtime.InteropServices.DllImport("user32.dll", ExactSpelling = true)]
public static extern IntPtr GetDCEx(
IntPtr hWnd,
IntPtr hrgnClip,
int flags
);
//Window Procedure Hook
protected override void WndProc(ref Message m)
{
//Don't style window in designer...
if (DesignMode)
base.WndProc(ref m);
//Handle Message
switch ((uint)m.Msg)
{
case WM_NCCALCSIZE: WmNCCalcSize(ref m); break;
case WM_NCPAINT: WmNCPaint(ref m); break;
default: base.WndProc(ref m); break;
}
}
//Handle Creation
protected override void OnHandleCreated(EventArgs e)
{
//Base Procedure...
base.OnHandleCreated(e);
//Remove Theme
SetWindowTheme(this.Handle, string.Empty, string.Empty);
}
//WM_NCCALCSIZE
private void WmNCCalcSize(ref Message m)
{
//Get Window Rect
RECT formRect = new RECT();
GetWindowRect(m.HWnd, out formRect);
//Check WPARAM
if (m.WParam != IntPtr.Zero) //TRUE
{
//When TRUE, LPARAM Points to a NCCALCSIZE_PARAMS structure
var nccsp = (NCCALCSIZE_PARAMS)System.Runtime.InteropServices.Marshal.PtrToStructure(m.LParam, typeof(NCCALCSIZE_PARAMS));
//We're adjusting the size of the client area here. Right now, the client area is the whole form.
//Adding to the Top, Bottom, Left, and Right will size the client area.
nccsp.rgrc0.top += 30; //30-pixel top border
nccsp.rgrc0.bottom -= 4; //4-pixel bottom (resize) border
nccsp.rgrc0.left += 4; //4-pixel left (resize) border
nccsp.rgrc0.right -= 4; //4-pixel right (resize) border
//Set the structure back into memory
System.Runtime.InteropServices.Marshal.StructureToPtr(nccsp, m.LParam, true);
}
else //FALSE
{
//When FALSE, LPARAM Points to a RECT structure
var clnRect = (RECT)System.Runtime.InteropServices.Marshal.PtrToStructure(m.LParam, typeof(RECT));
//Like before, we're adjusting the rectangle...
//Adding to the Top, Bottom, Left, and Right will size the client area.
clnRect.top += 30; //30-pixel top border
clnRect.bottom -= 4; //4-pixel bottom (resize) border
clnRect.left += 4; //4-pixel left (resize) border
clnRect.right -= 4; //4-pixel right (resize) border
//Set the structure back into memory
System.Runtime.InteropServices.Marshal.StructureToPtr(clnRect, m.LParam, true);
}
//Return Zero
m.Result = IntPtr.Zero;
}
//WM_NCPAINT
private void WmNCPaint(ref Message m)
{
//Store HDC
IntPtr HDC = IntPtr.Zero;
Graphics gfx = null;
//Check the WPARAM
if(m.WParam == (IntPtr)1)
{
//For reasons unknown to me, the update region doesn't contain valid data and calling GetDCEx will do nothing.
//So I call GetWindowDC and exclude the area using System.Drawing.Graphics instead.
//Graphics Object from HDC
HDC = GetWindowDC(m.HWnd);
gfx = Graphics.FromHdc(HDC);
//Exclude Client Area
gfx.ExcludeClip(new Rectangle(4, 30, Width - 8, 34)); //Exclude Client Area (GetWindowDC grabs the WHOLE window's graphics handle)
}
else
{
//Graphics Object from HDC
HDC = GetDCEx(m.HWnd, m.WParam, DCX_WINDOW | DCX_INTERSECTRGN);
gfx = Graphics.FromHdc(HDC);
}
//Call Paint
using (PaintEventArgs ncPaintArgs = new PaintEventArgs(gfx, new Rectangle(0, 0, Width, Height)))
MyForm_NCPaint(this, ncPaintArgs);
//Return Zero
m.Result = IntPtr.Zero;
}
public MyForm()
{
InitializeComponent();
}
private void MyForm_NCPaint(object sender, PaintEventArgs e)
{
//Clear
e.Graphics.Clear(Color.Green);
}
}

Multiline combobox dropdown list

I am trying to figure out the best way to populate address fields from a select list (vague but read on)..
The layout:
When I select the Address dropdown, I would like to see a nice list of full addresses, ie, with street name, country, postcode, etc. but as Im sure you are aware, combo's are one liners only.
Ideal scenario:
The result:
Has anyone a method for doing this?

Here is the full solution and as you can see, its perfectly what I wanted.
The ComboBoxEx is a class derived from a ComboBox which I have copied last. The reason for it is to set the height of the Items container (DropDownHeight). Without it, the container is calculated on the size of the first item x no. of items, and since the first item is zero height, the container would be zero height. So it needed a new class.
using System;
using System.Data;
using System.Drawing;
using System.Windows.Forms;
namespace WindowsFormsApplication1
{
public partial class Form1 : Form
{
public Form1()
{
InitializeComponent();
InitializeComboBox();
}
private ComboxBoxEx cbox1 = new ComboxBoxEx();
private DataTable items = new DataTable();
private void InitializeComboBox()
{
items.Columns.AddRange(new DataColumn[] { new DataColumn("id"), new DataColumn("name"), new DataColumn("address") });
items.Rows.Add(new object[] { 0, "[Please choose an address]", "" });
items.Rows.Add(new object[] { 1, "Country", "Country" });
items.Rows.Add(new object[] { 2, "House name", "House name\nStreet name\nTown name\nPostcode\nCountry" });
items.Rows.Add(new object[] { 3, "House name", "House name\nStreet name\nTown name\nPostcode\nCountry" });
cbox1.Location = new Point(39, 20);
cbox1.Size = new System.Drawing.Size(198, 21);
cbox1.DrawMode = DrawMode.OwnerDrawVariable;
cbox1.DrawItem += new DrawItemEventHandler(comboBox2_DrawItem);
cbox1.MeasureItem += new MeasureItemEventHandler(comboBox2_MeasureItem);
cbox1.SelectedIndexChanged += new EventHandler(comboBox2_SelectedIndexChanged);
//cbox1.DropDownWidth = 250;
//cbox1.DropDownHeight = 300;
//cbox1.MaxDropDownItems = 6;
this.Controls.Add(cbox1);
cbox1.ValueMember = "id";
cbox1.DisplayMember = "name";
cbox1.DataSource = new BindingSource(items, null);
//cbox1.SelectedIndex = -1;
}
private void comboBox2_MeasureItem(object sender, MeasureItemEventArgs e)
{
ComboxBoxEx cbox = (ComboxBoxEx)sender;
DataRowView item = (DataRowView)cbox.Items[e.Index];
string txt = item["address"].ToString();
int height = Convert.ToInt32(e.Graphics.MeasureString(txt, cbox.Font).Height);
e.ItemHeight = height + 4;
e.ItemWidth = cbox.DropDownWidth;
cbox.ItemHeights.Add(e.ItemHeight);
}
private void comboBox2_DrawItem(object sender, DrawItemEventArgs e)
{
ComboxBoxEx cbox = (ComboxBoxEx)sender;
DataRowView item = (DataRowView)cbox.Items[e.Index];
string txt = item["address"].ToString();
e.DrawBackground();
e.Graphics.DrawString(txt, cbox.Font, System.Drawing.Brushes.Black, new RectangleF(e.Bounds.X + 2, e.Bounds.Y + 2, e.Bounds.Width, e.Bounds.Height));
e.Graphics.DrawLine(new Pen(Color.LightGray), e.Bounds.X, e.Bounds.Top + e.Bounds.Height - 1, e.Bounds.Width, e.Bounds.Top + e.Bounds.Height - 1);
e.DrawFocusRectangle();
}
private void comboBox2_SelectedIndexChanged(object sender, EventArgs e)
{
ComboxBoxEx cbox = (ComboxBoxEx)sender;
if (cbox.SelectedItem == null) return;
DataRowView item = (DataRowView)cbox.SelectedItem;
//label1.Text = item["id"].ToString();
}
}
}
The ComboBoxEx Class
using System;
using System.Windows.Forms;
using System.Runtime.InteropServices;
using System.Collections.Generic;
namespace WindowsFormsApplication1
{
public partial class ComboxBoxEx : ComboBox
{
[DllImport("user32.dll")]
[return: MarshalAs(UnmanagedType.Bool)]
public static extern bool GetWindowRect(IntPtr hwnd, out RECT lpRect);
[DllImport("user32.dll", SetLastError = true)]
[return: MarshalAs(UnmanagedType.Bool)]
private static extern bool SetWindowPos(IntPtr hWnd, IntPtr hWndInsertAfter, int x, int y, int cx, int cy, uint uFlags);
[StructLayout(LayoutKind.Sequential)]
public struct RECT
{
public int Left; // x position of upper-left corner
public int Top; // y position of upper-left corner
public int Right; // x position of lower-right corner
public int Bottom; // y position of lower-right corner
}
public const int SWP_NOZORDER = 0x0004;
public const int SWP_NOACTIVATE = 0x0010;
public const int SWP_FRAMECHANGED = 0x0020;
public const int SWP_NOOWNERZORDER = 0x0200;
public const int WM_CTLCOLORLISTBOX = 0x0134;
private int _hwndDropDown = 0;
internal List<int> ItemHeights = new List<int>();
protected override void WndProc(ref Message m)
{
if (m.Msg == WM_CTLCOLORLISTBOX)
{
if (_hwndDropDown == 0)
{
_hwndDropDown = m.LParam.ToInt32();
RECT r;
GetWindowRect((IntPtr)_hwndDropDown, out r);
int newHeight = 0;
int n = (Items.Count > MaxDropDownItems) ? MaxDropDownItems : Items.Count;
for (int i = 0; i < n; i++)
{
newHeight += ItemHeights[i];
}
newHeight += 5; //to stop scrollbars showing
SetWindowPos((IntPtr)_hwndDropDown, IntPtr.Zero,
r.Left,
r.Top,
DropDownWidth,
newHeight,
SWP_FRAMECHANGED |
SWP_NOACTIVATE |
SWP_NOZORDER |
SWP_NOOWNERZORDER);
}
}
base.WndProc(ref m);
}
protected override void OnDropDownClosed(EventArgs e)
{
_hwndDropDown = 0;
base.OnDropDownClosed(e);
}
}
}

disable scrolling in RichTextBox (c#)

I wrote code to display the text in separate pages, like Microsoft Word, I use a Collection of text boxes, and when the user filled one text box, new box is displayed automatically, and the cursor moves to her.
The problem is that when the user writes the last line in the text box, the box scrolls down a bit, as you will see when you will run this code, so how can I disable the scrolling.
the code :
using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Linq;
using System.Text;
using System.Windows.Forms;
using System.Runtime.InteropServices;
namespace WindowsFormsApplication1
{
public partial class Form1 : Form
{
List<myRTB> pages; // collection of our RichTextBox, use as pages
public Form1()
{
InitializeComponent();
pages = new List<myRTB>();
pages.Add(new myRTB());
pages[0].Width = 200;
pages[0].Height = 290;
pages[0].Location = new Point(50, 10);
pages[0].Name = "0";
this.Controls.Add(pages[0]);
this.Width = 300;
this.Height = 360;
this.AutoScroll = true;
}
public void AddPage(int correntPageIndex)
{
if (correntPageIndex == (pages.Count - 1))
{
// create a new page
pages.Add(new myRTB());
pages[correntPageIndex + 1].Width = 200;
pages[correntPageIndex + 1].Height = 290;
pages[correntPageIndex + 1].Location = new Point(50, pages[correntPageIndex].Location.Y + 300);
this.Controls.Add(pages[pages.Count - 1]);
this.Name = (correntPageIndex + 1).ToString();
}
bool CursorInEnd = (pages[correntPageIndex].SelectionStart == pages[correntPageIndex].TextLength);
// Transfer the last word on the previous page, to the new page
int lastLineIndex = pages[correntPageIndex].GetLineFromCharIndex(pages[correntPageIndex].TextLength - 2);
// find the index of the first char in the last line
int indexOfFirstCharInLastLine = pages[correntPageIndex].GetFirstCharIndexFromLine(lastLineIndex);
// find the index of the last space in the last line
int indexOfLastSpace = pages[correntPageIndex].Text.LastIndexOf(' ', indexOfFirstCharInLastLine);
string restOfString;
if (indexOfLastSpace < 0) // no spaces in the last line
{
restOfString = pages[correntPageIndex].Text.Substring(pages[correntPageIndex].TextLength - 1);
pages[correntPageIndex + 1].Text.Insert(0, restOfString);
pages[correntPageIndex].Text.Remove(pages[correntPageIndex].TextLength - 1);
}
else // there is spaces in the last line
{
restOfString = pages[correntPageIndex].Text.Substring(indexOfLastSpace + 1);
pages[correntPageIndex + 1].Text = pages[correntPageIndex + 1].Text.Insert(0, restOfString);
pages[correntPageIndex].Text = pages[correntPageIndex].Text.Remove(indexOfLastSpace + 1);
}
if (CursorInEnd)
{
// Move the cursor to next page
pages[correntPageIndex + 1].SelectionStart = restOfString.Length;
pages[correntPageIndex + 1].Focus();
}
}
}
class myRTB : RichTextBox
{
public myRTB()
{
this.ScrollBars = RichTextBoxScrollBars.None;
}
protected override void WndProc(ref Message m)
{
// catch the request resize message
if (m.Msg == (WM_REFLECT | WM_NOTIFY))
{
REQRESIZE rrs = (REQRESIZE)(Marshal.PtrToStructure(m.LParam, typeof(REQRESIZE)));
if (rrs.nmhdr.code == EN_REQUESTRESIZE)
{
if (rrs.rc.ToRectangle().Height > this.ClientRectangle.Height)
{
((Form1)Parent).AddPage(int.Parse(this.Name));
}
}
}
base.WndProc(ref m);
}
[StructLayout(LayoutKind.Sequential)]
public struct NMHDR
{
public IntPtr HWND;
public uint idFrom;
public int code;
public override String ToString()
{
return String.Format("Hwnd: {0}, ControlID: {1}, Code: {2}",
HWND, idFrom, code);
}
}
[StructLayout(LayoutKind.Sequential)]
public struct REQRESIZE
{
public NMHDR nmhdr;
public RECT rc;
}
[StructLayout(LayoutKind.Sequential)]
public struct RECT
{
public int Left, Top, Right, Bottom;
public override string ToString()
{
return String.Format("{0}, {1}, {2}, {3}", Left, Top, Right,
Bottom);
}
public Rectangle ToRectangle()
{
return Rectangle.FromLTRB(Left, Top, Right, Bottom);
}
}
public const int WM_USER = 0x400;
public const int WM_NOTIFY = 0x4E;
public const int WM_REFLECT = WM_USER + 0x1C00;
public const int EN_REQUESTRESIZE = 0x701;
}
}

To ensure that the text does not scroll automatically, take a look at the following answer to a similar problem.
Disabling RichTextBox autoscroll
Here's another great answer to your problem:
Prevent Autoscrolling in RichTextBox
I copied over the code from the link above, please ensure to give that user credit for providing this code (its not mine)
[System.Runtime.InteropServices.DllImport("user32.dll")]
static extern IntPtr SendMessage(IntPtr hWnd, UInt32 Msg, Int32 wParam, Int32 lParam);
const int WM_USER = 0x400;
const int EM_HIDESELECTION = WM_USER + 63;
void OnAppend(string text)
{
bool focused = richTextBox1.Focused;
//backup initial selection
int selection = richTextBox1.SelectionStart;
int length = richTextBox1.SelectionLength;
//allow autoscroll if selection is at end of text
bool autoscroll = (selection==richTextBox1.Text.Length);
if (!autoscroll)
{
//shift focus from RichTextBox to some other control
if (focused)
textBox1.Focus();
//hide selection
SendMessage(richTextBox1.Handle, EM_HIDESELECTION, 1, 0);
}
richTextBox1.AppendText(text);
if (!autoscroll)
{
//restore initial selection
richTextBox1.SelectionStart = selection;
richTextBox1.SelectionLength = length;
//unhide selection
SendMessage(richTextBox1.Handle, EM_HIDESELECTION, 0, 0);
//restore focus to RichTextBox
if(focused) richTextBox1.Focus();
}
}

Transparent window layer that is click-through and always stays on top

This is some code that I picked up which I tried to implement. Its purpose is to create a form layer which is transparent, full screen, borderless, clickthrough, and always on top of other windows. It then lets you draw using directx over the top of it remaining otherwise transparent.
The parts that don't work are the click-through part, and the directx render. When I run it I basically have an invisible force field in front of all other windows and have to alt-tab around to visual studio to quickly press ALT F5 and end the debug (so at least the always on top and transparency works). I have been trying to figure out why those parts don't work, but my newbie c# skills fail me. hopefully someone can spot why and provide a modification.
using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Text;
using System.Windows.Forms;
using System.Diagnostics;
using System.Runtime.InteropServices;
using System.Globalization;
using Microsoft.DirectX;
using Microsoft.DirectX.Direct3D;
using System.Threading;
namespace MinimapSpy
{
public partial class Form1 : Form
{
private Margins marg;
//this is used to specify the boundaries of the transparent area
internal struct Margins
{
public int Left, Right, Top, Bottom;
}
[DllImport("user32.dll", SetLastError = true)]
private static extern UInt32 GetWindowLong(IntPtr hWnd, int nIndex);
[DllImport("user32.dll")]
static extern int SetWindowLong(IntPtr hWnd, int nIndex, IntPtr dwNewLong);
[DllImport("user32.dll")]
static extern bool SetLayeredWindowAttributes(IntPtr hwnd, uint crKey, byte bAlpha, uint dwFlags);
public const int GWL_EXSTYLE = -20;
public const int WS_EX_LAYERED = 0x80000;
public const int WS_EX_TRANSPARENT = 0x20;
public const int LWA_ALPHA = 0x2;
public const int LWA_COLORKEY = 0x1;
[DllImport("dwmapi.dll")]
static extern void DwmExtendFrameIntoClientArea(IntPtr hWnd, ref Margins pMargins);
private Device device = null;
public Form1()
{
//Make the window's border completely transparant
SetWindowLong(this.Handle, GWL_EXSTYLE,
(IntPtr)(GetWindowLong(this.Handle, GWL_EXSTYLE) ^ WS_EX_LAYERED ^ WS_EX_TRANSPARENT));
//Set the Alpha on the Whole Window to 255 (solid)
SetLayeredWindowAttributes(this.Handle, 0, 255, LWA_ALPHA);
//Init DirectX
//This initializes the DirectX device. It needs to be done once.
//The alpha channel in the backbuffer is critical.
PresentParameters presentParameters = new PresentParameters();
presentParameters.Windowed = true;
presentParameters.SwapEffect = SwapEffect.Discard;
presentParameters.BackBufferFormat = Format.A8R8G8B8;
this.device = new Device(0, DeviceType.Hardware, this.Handle,
CreateFlags.HardwareVertexProcessing, presentParameters);
Thread dx = new Thread(new ThreadStart(this.dxThread));
dx.IsBackground = true;
dx.Start();
InitializeComponent();
}
protected override void OnPaint(PaintEventArgs e)
{
//Create a margin (the whole form)
marg.Left = 0;
marg.Top = 0;
marg.Right = this.Width;
marg.Bottom = this.Height;
//Expand the Aero Glass Effect Border to the WHOLE form.
// since we have already had the border invisible we now
// have a completely invisible window - apart from the DirectX
// renders NOT in black.
DwmExtendFrameIntoClientArea(this.Handle, ref marg);
}
private void Form1_Load(object sender, EventArgs e)
{
}
private void dxThread()
{
while (true)
{
//Place your update logic here
device.Clear(ClearFlags.Target, Color.FromArgb(0, 0, 0, 0), 1.0f, 0);
device.RenderState.ZBufferEnable = false;
device.RenderState.Lighting = false;
device.RenderState.CullMode = Cull.None;
device.Transform.Projection = Matrix.OrthoOffCenterLH(0, this.Width, this.Height, 0, 0, 1);
device.BeginScene();
//Place your rendering logic here
device.EndScene();
//device.Present();
}
this.device.Dispose();
Application.Exit();
}
}

Here's a refined full sample code for making a window topmost - click through - transparent (= alpha blended). The sample makes a rotating color wheel which is rendered with DirectX, or actually with XNA 4.0, because I believe Microsoft has discontinued developing the managed directx and favours XNA today.
using System;
using System.Windows.Forms;
using System.Runtime.InteropServices;
using Microsoft.Xna.Framework.Graphics;
namespace ClickThroughXNA
{
public partial class Form1 : Form
{
// Directx graphics device
GraphicsDevice dev = null;
BasicEffect effect = null;
// Wheel vertexes
VertexPositionColor[] v = new VertexPositionColor[100];
// Wheel rotation
float rot = 0;
public Form1()
{
InitializeComponent();
StartPosition = FormStartPosition.CenterScreen;
Size = new System.Drawing.Size(500, 500);
FormBorderStyle = System.Windows.Forms.FormBorderStyle.None; // no borders
TopMost = true; // make the form always on top
Visible = true; // Important! if this isn't set, then the form is not shown at all
// Set the form click-through
int initialStyle = GetWindowLong(this.Handle, -20);
SetWindowLong(this.Handle, -20, initialStyle | 0x80000 | 0x20);
// Create device presentation parameters
PresentationParameters p = new PresentationParameters();
p.IsFullScreen = false;
p.DeviceWindowHandle = this.Handle;
p.BackBufferFormat = SurfaceFormat.Vector4;
p.PresentationInterval = PresentInterval.One;
// Create XNA graphics device
dev = new GraphicsDevice(GraphicsAdapter.DefaultAdapter, GraphicsProfile.Reach, p);
// Init basic effect
effect = new BasicEffect(dev);
// Extend aero glass style on form init
OnResize(null);
}
protected override void OnResize(EventArgs e)
{
int[] margins = new int[] { 0, 0, Width, Height };
// Extend aero glass style to whole form
DwmExtendFrameIntoClientArea(this.Handle, ref margins);
}
protected override void OnPaintBackground(PaintEventArgs e)
{
// do nothing here to stop window normal background painting
}
protected override void OnPaint(PaintEventArgs e)
{
// Clear device with fully transparent black
dev.Clear(new Microsoft.Xna.Framework.Color(0, 0, 0, 0.0f));
// Rotate wheel a bit
rot+=0.1f;
// Make the wheel vertexes and colors for vertexes
for (int i = 0; i < v.Length; i++)
{
if (i % 3 == 1)
v[i].Position = new Microsoft.Xna.Framework.Vector3((float)Math.Sin((i + rot) * (Math.PI * 2f / (float)v.Length)), (float)Math.Cos((i + rot) * (Math.PI * 2f / (float)v.Length)), 0);
else if (i % 3 == 2)
v[i].Position = new Microsoft.Xna.Framework.Vector3((float)Math.Sin((i + 2 + rot) * (Math.PI * 2f / (float)v.Length)), (float)Math.Cos((i + 2 + rot) * (Math.PI * 2f / (float)v.Length)), 0);
v[i].Color = new Microsoft.Xna.Framework.Color(1 - (i / (float)v.Length), i / (float)v.Length, 0, i / (float)v.Length);
}
// Enable position colored vertex rendering
effect.VertexColorEnabled = true;
foreach (EffectPass pass in effect.CurrentTechnique.Passes) pass.Apply();
// Draw the primitives (the wheel)
dev.DrawUserPrimitives(PrimitiveType.TriangleList, v, 0, v.Length / 3, VertexPositionColor.VertexDeclaration);
// Present the device contents into form
dev.Present();
// Redraw immediatily
Invalidate();
}
[DllImport("user32.dll", SetLastError = true)]
static extern int GetWindowLong(IntPtr hWnd, int nIndex);
[DllImport("user32.dll")]
static extern int SetWindowLong(IntPtr hWnd, int nIndex, int dwNewLong);
[DllImport("dwmapi.dll")]
static extern void DwmExtendFrameIntoClientArea(IntPtr hWnd, ref int[] pMargins);
}
}

A little extension/modification to Jaska's code, which the form is transparent
public partial class Form1 : Form
{
public Form1()
{
InitializeComponent();
this.TopMost = true; // make the form always on top
this.FormBorderStyle = System.Windows.Forms.FormBorderStyle.None; // hidden border
this.WindowState = FormWindowState.Maximized; // maximized
this.MinimizeBox = this.MaximizeBox = false; // not allowed to be minimized
this.MinimumSize = this.MaximumSize = this.Size; // not allowed to be resized
this.TransparencyKey = this.BackColor = Color.Red; // the color key to transparent, choose a color that you don't use
}
protected override CreateParams CreateParams
{
get
{
CreateParams cp = base.CreateParams;
// Set the form click-through
cp.ExStyle |= 0x80000 /* WS_EX_LAYERED */ | 0x20 /* WS_EX_TRANSPARENT */;
return cp;
}
}
protected override void OnPaint(PaintEventArgs e)
{
base.OnPaint(e);
// draw what you want
e.Graphics.FillEllipse(Brushes.Blue, 30, 30, 100, 100);
}
}

Change your extended window style to only WS_EX_LAYERED, window style to only WS_POPUP (NO WS_SIZEBOX) and make sure to use DwmExtendFrameIntoClientArea with all -1's and this will produce transparent windows with layered support: downside is you need to bltbit with GDI from an offscreen directx rendering. Not optimal but it works. This gives mouse click throughs + directx rendering + transparency. Downside is you'll need to inform GDI anytime, pull the directx buffer (all of it or just the damaged portions) and write them to the screem with bltbit.
Setting the extended window style to WS_EX_COMPOSITED and DwmExtendedFrameIntoClientArea with all -1's (similar as above, WS_POPUP on the regular window style). This you can run directx from but no mouse clickthroughs. You can at this point define irregular paths for the hit mask and pass it to windows, its not perfect but if you know a general (non regular) area that can pass-through it'll work.
Still trying to find a true way of using opengl/directx on mac or windows platforms that can pass through mouse clicks with out having to do a bitblt to a legacy rendering system.

I have a simple way use TransparentKey property and a 1x1 pixel label with the color of Form TransparentKey.
On Form and all control MouseMouse event. Set label position to Mouse location.
private void MoveHole()
{
var newLocation = PointToClient(MousePosition);
lblHole.Location = newLocation;
}