Develop Reference

Menu out of place when application is in full screen by Windows API

I have developed an application in C# and I want to show it in full screen mode. It should also cover up the taskbar. To accomplish this I have used the Windows API. You can find the class below:
public sealed class WinAPI
{
[DllImport("user32.dll", EntryPoint = "GetSystemMetrics")]
public static extern int GetSystemMetrics(int which);
[DllImport("user32.dll")]
public static extern void
SetWindowPos(IntPtr hwnd, IntPtr hwndInsertAfter,
int X, int Y, int width, int height, uint flags);
private const int SM_CXSCREEN = 0;
private const int SM_CYSCREEN = 1;
private static IntPtr HWND_TOP = IntPtr.Zero;
private const int SWP_SHOWWINDOW = 64; // 0×0040
public static int ScreenX
{
get { return GetSystemMetrics(SM_CXSCREEN); }
}
public static int ScreenY
{
get { return GetSystemMetrics(SM_CYSCREEN); }
}
public static void SetWinFullScreen(IntPtr hwnd)
{
SetWindowPos(hwnd, HWND_TOP, 0, 0, ScreenX, ScreenY, SWP_SHOWWINDOW);
}
}
I am using this class in conjunction with the following form settings to go in full screen mode:
private void terminalModeToolStripMenuItem_Click(object sender, EventArgs e)
{
// Remove the border.
this.FormBorderStyle = System.Windows.Forms.FormBorderStyle.None;
this.WindowState = FormWindowState.Maximized;
this.Bounds = Screen.PrimaryScreen.Bounds;
// Full screen windows API hack.
WinAPI.SetWinFullScreen(this.Handle);
}
Now comes the funny part. If I click a button in my menu bar it will show up with a gap between the button and the menu as you can see in the image below:
Does anyone knows how to fix this issue? I would like it to show up like this:
And why does this happen anyway?

As Muraad pointed you to in his comment, try moving the following block of code into your Form load event:
// Remove the border.
this.FormBorderStyle = System.Windows.Forms.FormBorderStyle.None;
this.WindowState = FormWindowState.Maximized;
this.Bounds = Screen.PrimaryScreen.Bounds;
And see if the issue still persists.

This problem is caused by having the task bar set to the top of the screen.
It can be resolved by either moving the task bar to the bottom of the screen, or by enabling the Auto-hide task bar check box in the Properties window of the task bar.
EDIT: As stated by #slashp 's comments. The root cause of this issue comes from some inner mechanics in drawing the menu. The menu has a safety to be always drawn within the working area. Which seems to be your screen - task bar. Because the application is placed over the task bar, the calculation is placing the menu below the task bar. (you can't see it, but it's still there)

How to convert System.Windows.Input.Cursor to ImageSource?

I have a .cur file path ("%SystemRoot%\cursors\aero_arrow.cur") witch I want to display in an image control. So I need to convert Cursor to ImageSource. I tried both CursorConverter and ImageSourceConverter but had no luck. I also tried creating Graphics from the cursor and then converting it to Bitmap, But that didn't work either.
This thread says:
it is complicated to convert Cursor to Icon direcetly because Cursor
doesn't expose the imagesource it use.
and
If you really want to bind an image to cursor, there is an approach
you might want to try.
Since WindowForm is capable of drawing the cursor, we can use
WindowForm to draw cursor on a bitmap. After that we could find a way
to copy that bitmap to something WPF support.
Now the funny thing is that I can't create a new instance of System.Windows.Forms.Cursor with neither the file path nor the stream since It throws the following exception:
System.Runtime.InteropServices.COMException (0x800A01E1):
Exception from HRESULT: 0x800A01E1 (CTL_E_INVALIDPICTURE)
at System.Windows.Forms.UnsafeNativeMethods.IPersistStream.Load(IStream pstm)
at System.Windows.Forms.Cursor.LoadPicture(IStream stream)
So can anybody tell me the best way to convert System.Windows.Input.Cursor to ImageSource?
And what about .ani cursors? If I remember correctly System.Windows.Input.Cursor does not support animated cursors, So how can I show them to the user? Converting them to gif then using the 3d party gif libraries?

I found the solution in this thread: How to Render a Transparent Cursor to Bitmap preserving alpha channel?
So here is the code:
[StructLayout(LayoutKind.Sequential)]
private struct ICONINFO
{
public bool fIcon;
public int xHotspot;
public int yHotspot;
public IntPtr hbmMask;
public IntPtr hbmColor;
}
[DllImport("user32")]
private static extern bool GetIconInfo(IntPtr hIcon, out ICONINFO pIconInfo);
[DllImport("user32.dll")]
private static extern IntPtr LoadCursorFromFile(string lpFileName);
[DllImport("gdi32.dll", SetLastError = true)]
private static extern bool DeleteObject(IntPtr hObject);
private Bitmap BitmapFromCursor(Cursor cur)
{
ICONINFO ii;
GetIconInfo(cur.Handle, out ii);
Bitmap bmp = Bitmap.FromHbitmap(ii.hbmColor);
DeleteObject(ii.hbmColor);
DeleteObject(ii.hbmMask);
BitmapData bmData = bmp.LockBits(new Rectangle(0, 0, bmp.Width, bmp.Height), ImageLockMode.ReadOnly, bmp.PixelFormat);
Bitmap dstBitmap = new Bitmap(bmData.Width, bmData.Height, bmData.Stride, PixelFormat.Format32bppArgb, bmData.Scan0);
bmp.UnlockBits(bmData);
return new Bitmap(dstBitmap);
}
private void Form1_Paint(object sender, System.Windows.Forms.PaintEventArgs e)
{
//Using LoadCursorFromFile from user32.dll, get a handle to the icon
IntPtr hCursor = LoadCursorFromFile("C:\\Windows\\Cursors\\Windows Aero\\aero_busy.ani");
//Create a Cursor object from that handle
Cursor cursor = new Cursor(hCursor);
//Convert that cursor into a bitmap
using (Bitmap cursorBitmap = BitmapFromCursor(cursor))
{
//Draw that cursor bitmap directly to the form canvas
e.Graphics.DrawImage(cursorBitmap, 50, 50);
}
}
It's written for Win Forms and draws an image. But can be used in wpf as well with referencing to System.Windows.Forms. and then you can convert that bitmap to bitmap source and show it in an image control...
The reason I'm using System.Windows.Forms.Cursor instead of System.Windows.Input.Cursor is that I can't get to create a new instance of cursor using the IntPtr handle...
Edit: The above method does NOT work with cursors having low color bits.
An alternative is to use Icon.ExtractAssociatedIcon instead:
System.Drawing.Icon i = System.Drawing.Icon.ExtractAssociatedIcon(#"C:\Windows\Cursors\arrow_rl.cur");
System.Drawing.Bitmap b = i.ToBitmap();
Hope that helps someone ...

Drawing and clearing on screen with Graphics.FromHwnd

I am trying to create a program which gets the handle of the window under your cursor, show's some data about it and draws a filled rectangle (with very low alpha) on top of the whole window. I am using C# and winforms.
I have succeeded in doing so, but the problem is my draw method is in a BackgroundWorker's loop and it keeps making more and more rectangles (-> rectangle with higher alpha) on the window or when moving mouse to another window the old one still exists.
I haven't managed to find a method to clear the drawn rectangle as it just "is" on the screen and isn't bound to the graphics object or anything.
I have tried using certain native methods such as
[DllImport("User32.dll")]
public static extern Int64 SendMessage(IntPtr hWnd, uint msg, IntPtr wParam, IntPtr lParam);
[DllImport("user32.dll")]
public static extern bool InvalidateRect(IntPtr hWnd, IntPtr lpRect, bool bErase);
[DllImport("user32.dll")]
public static extern bool UpdateWindow(IntPtr hWnd);
[DllImport("user32.dll")]
public static extern bool RedrawWindow(IntPtr hWnd, IntPtr lprcUpdate, IntPtr hrgnUpdate, RedrawWindowFlags flags);
but none of the above has worked correctly. Some of them do work but as the messages get in the queue the redrawing doesn't occur immediately or is very slow and glitched (flickering etc).
So, the question is, how would I "remove" the rectangle I have drawn using Graphics.FromHwnd(handleOfWindowUnderCursor)? I actually think it doesn't matter that it is drawn on other window as I have had the very same problem earlier when trying to get rid of the drawings on my own form too (never got that fixed either!).
Alternatively, any suggestions on how I could accomplish drawing and removing the rectangle on the window under cursor without using the methods I am now?

I noticed that drawing using
Graphics g = Graphics.FromHwnd(form.Handle);
draws on the form background, under its controls. Is it whatyou want to acomplish?
// draw the rectangle
Brush b = new SolidBrush(Color.FromArgb(20, 0, 0, 255));
g.FillRectangle(b, new Rectangle(5, 5, 200, 200));
// clear the rectangle
g.Clear(this.BackColor);
If I draw on the screen directly, with this:
Graphics g = Graphics.FromHwnd(IntPtr.Zero);
the rectangle disapears immediately after Windows refreshes the screen.
There is a third option, which is not realy strightforward.
Instead of drawing a rectangle, create a form with lowered opacity, TopMost property set to true and without borders. Then make it transparent to events:
protected override void WndProc(ref Message m)
{
const int WM_NCHITTEST = 0x0084;
const int HTTRANSPARENT = (-1);
if (m.Msg == WM_NCHITTEST)
{
m.Result = (IntPtr)HTTRANSPARENT;
}
else
{
base.WndProc(ref m);
}
}
The only things you have to take care after that is this form's Visible, Location and Size properties.

bool change = false;
private void timer1_Tick(object sender, EventArgs e)
{
try
{
if (change)
{
InvalidateRect(IntPtr.Zero, IntPtr.Zero, true);
change = false;
}
else
{
PaintRectangleToScreen();
change = true;
}
}
catch (System.Exception caught)
{
MessageBox.Show(caught.Message);
}
}

Setting calendar size when overriding DateTimePicker to add week numbers

I'm trying to create a DateTimePicker with week numbers displayed, as shown here (Code project example).
It works fairly well, except for one minor detail; The calender popping up when trying to select a date is not the right size. As you can see, the calendar area is sort of "cramped", especially along the right edge.
I can click the bottom right corner here, and drag it out a little - just enough to expand it so that it looks right:
I can't seem to find any way to force the calendar to be the correct/full size from the beginning, or to resize it.

Finally found a solution that seems to work - at least for now.
It seems there are two windows in the calendar part of the DateTimePicker. Apparently my code would automatically find the correct size for the inner one (more or less at least?), but not the outer one.
A bit of research has led to the code below. The following links provide some useful and relevant info:
GetWindowLong function (Used for getting info about the window to edit)
GetParent function (Finding the outer window, so we could apply settings to that too)
The trick was to add a little to the height and width of the (inner) window, then apply the same height and width to the outer window (which I access using the GetParrent() function). I found the "correct" size by trial and error: When the size matched what was needed for the contents of the calendar, it could not be resized any longer.
Yes, this feels a little like a hack, and no, I haven't been able to verify that it works perfectly on other computers than my own yet. I'm a little worried about having to give specific values for height and width, but I'm hoping this won't be affected by screen resolutions or whatever else.
Hope someone else in a similar situation will find the code useful.
(The following can directly replace a regular DateTimePicker to show week numbers in the calendar)
using System;
using System.ComponentModel;
using System.Drawing;
using System.Runtime.InteropServices;
using System.Windows.Forms;
public class DatePickerWithWeekNumbers : DateTimePicker
{
[DllImport("User32.dll")]
private static extern int GetWindowLong(IntPtr handleToWindow,
int offsetToValueToGet);
[DllImport("User32.dll")]
private static extern int SetWindowLong(IntPtr h,
int index,
int value);
private const int McmFirst = 0x1000;
private const int McmGetminreqrect = (McmFirst + 9);
private const int McsWeeknumbers = 0x4;
private const int DtmFirst = 0x1000;
private const int DtmGetmonthcal = (DtmFirst + 8);
[DllImport("User32.dll")]
private static extern IntPtr SendMessage(IntPtr h,
int msg,
int param,
int data);
[DllImport("User32.dll")]
private static extern IntPtr GetParent(IntPtr h);
[DllImport("User32.dll")]
private static extern int SendMessage(IntPtr h,
int msg,
int param,
ref Rectangle data);
[DllImport("User32.dll")]
private static extern int MoveWindow(IntPtr h,
int x,
int y,
int width,
int height,
bool repaint);
[Browsable(true), DesignerSerializationVisibility(
DesignerSerializationVisibility.Visible)]
public bool DisplayWeekNumbers { get; set; }
protected override void OnDropDown(EventArgs e)
{
// Hex value to specify that we want the style-attributes
// for the window:
const int offsetToGetWindowsStyles = (-16);
IntPtr pointerToCalenderWindow = SendMessage(Handle,
DtmGetmonthcal,
0,
0);
int styleForWindow = GetWindowLong(pointerToCalenderWindow,
offsetToGetWindowsStyles);
// Check properties for the control - matches available
// property in the graphical properties for the DateTimePicker:
if (DisplayWeekNumbers)
{
styleForWindow = styleForWindow | McsWeeknumbers;
}
else
{
styleForWindow = styleForWindow & ~McsWeeknumbers;
}
// Get the size needed to display the calendar (inner window)
var rect = new Rectangle();
SendMessage(pointerToCalenderWindow, McmGetminreqrect, 0, ref rect);
// Add to size as needed (I don't know why
// this was not correct initially!)
rect.Width = rect.Width + 28;
rect.Height = rect.Height + 6;
// Set window styles..
SetWindowLong(pointerToCalenderWindow,
offsetToGetWindowsStyles,
styleForWindow);
// Dont move the window - just resize it as needed:
MoveWindow(pointerToCalenderWindow,
0,
0,
rect.Right,
rect.Bottom,
true);
// Now access the parrent window..
var parentWindow = GetParent(pointerToCalenderWindow);
// ...and resize that the same way:
MoveWindow(parentWindow, 0, 0, rect.Right, rect.Bottom, true);
base.OnDropDown(e);
}
}

For me, setting MCS_WEEKNUMBERS via the DateTimePicker's DTM_SETMCSTYLE message automatically resulted in the correct size of the MonthCal control:
SendMessage(Handle, DTM_FIRST + 11, 0, SendMessage(Handle, DTM_FIRST + 12, 0, 0) | MCS_WEEKNUMBERS);
Where DTM_FIRST = 0x1000 and MCS_WEEKNUMBERS = 0x4 as in Kjartan's solution. DTM_FIRST + 11 is DTM_SETMCSTYLE and DTM_FIRST + 12 is DTM_GETMCSTYLE in Microsoft's documentation.
Unlike Kjartan's solution, this call must be used before the first dropdown, but right at form initialization didn't work for me in some cases, so I delayed it to when the form was already created and visible in these cases. One call is enough, the DateTimePicker will save the style for future dropdowns.

Ok, Try to comment line in Program.cs
Application.EnableVisualStyles();
and then try to execute.

How do I find the position / location of a window given a hWnd without NativeMethods?

I'm currently working with WatiN, and finding it to be a great web browsing automation tool. However, as of the last release, it's screen capturing functionality seems to be lacking. I've come up with a workable solution for capturing screenshots from the screen (independently generating code similar to this StackOverflow question) in addition to some code by Charles Petzold. Unfortunately, there is a missing component: Where is the actual window?
WatiN conveniently provides the browser's hWnd to you, so we can (with this simplified example) get set to copy an image from the screen, like so:
// browser is either an WatiN.Core.IE or a WatiN.Core.FireFox...
IntPtr hWnd = browser.hWnd;
string filename = "my_file.bmp";
using (Graphics browser = Graphics.FromHwnd(browser.hWnd) )
using (Bitmap screenshot = new Bitmap((int)browser.VisibleClipBounds.Width,
(int)browser.VisibleClipBounds.Height,
browser))
using (Graphics screenGraphics = Graphics.FromImage(screenshot))
{
int hWndX = 0; // Upper left of graphics? Nope,
int hWndY = 0; // this is upper left of the entire desktop!
screenGraphics.CopyFromScreen(hWndX, hWndY, 0, 0,
new Size((int)browser.VisibileClipBounds.Width,
(int)browser.VisibileClipBounds.Height));
screenshot.Save(filename, ImageFormat.Bmp);
}
Success! We get screenshots, but there's that problem: hWndX and hWndY always point to the upper left most corner of the screen, not the location of the window we want to copy from.
I then looked into Control.FromHandle, however this seems to only work with forms you created; this method returns a null pointer if you pass the hWnd into it.
Then, further reading lead me to switch my search criteria...I had been searching for 'location of window' when most people really want the 'position' of the window. This lead to another SO question that talked about this, but their answer was to use native methods.
So, Is there a native C# way of finding the position of a window, only given the hWnd (preferably with only .NET 2.0 era libraries)?

I just went through this on a project and was unable to find any managed C# way.
To add to Reed's answer the P/Invoke code is:
[DllImport("user32.dll", SetLastError = true)]
[return: MarshalAs(UnmanagedType.Bool)]
static extern bool GetWindowRect(IntPtr hWnd, ref RECT lpRect);
[StructLayout(LayoutKind.Sequential)]
private struct RECT
{
public int Left;
public int Top;
public int Right;
public int Bottom;
}
Call it as:
RECT rct = new RECT();
GetWindowRect(hWnd, ref rct);

No - if you didn't create the form, you have to P/Invoke GetWindowRect. I don't believe there is a managed equivalent.

The answer is as others have stated, probably "No, you cannot take a screenshot of a random window from an hwnd without native methods.". Couple of caveats before I show it:
Forewarning:
For anyone who wants to use this code, note that the size given from the VisibleClipBounds is only inside the window, and does not include the border or title bar. It's the drawable area. If you had that, you might be able to do this without p/invoke.
(If you could calculate the border of the browser window, you could use the VisibleClipBounds. If you wanted, you could use the SystemInformation object to get important info like Border3DSize, or you could try to calculate it by creating a dummy form and deriving the border and title bar height from that, but that all sounds like the black magic that bugs are made of.)
This is equivalent to Ctrl+Printscreen of the window. This also does not do the niceties that the WatiN screenshot capability does, such as scroll the browser and take an image of the whole page. This is suitable for my project, but may not be for yours.
Enhancements:
This could be changed to be an extension method if you're in .NET 3 and up-land, and an option for the image type could be added pretty easily (I default to ImageFormat.Bmp for this example).
Code:
using System.Drawing;
using System.Drawing.Imaging;
using System.Runtime.InteropServices;
public class Screenshot
{
class NativeMethods
{
// http://msdn.microsoft.com/en-us/library/ms633519(VS.85).aspx
[DllImport("user32.dll", SetLastError = true)]
[return: MarshalAs(UnmanagedType.Bool)]
public static extern bool GetWindowRect(IntPtr hWnd, ref RECT lpRect);
// http://msdn.microsoft.com/en-us/library/a5ch4fda(VS.80).aspx
[StructLayout(LayoutKind.Sequential)]
public struct RECT
{
public int Left;
public int Top;
public int Right;
public int Bottom;
}
}
/// <summary>
/// Takes a screenshot of the browser.
/// </summary>
/// <param name="b">The browser object.</param>
/// <param name="filename">The path to store the file.</param>
/// <returns></returns>
public static bool SaveScreenshot(Browser b, string filename)
{
bool success = false;
IntPtr hWnd = b.hWnd;
NativeMethods.RECT rect = new NativeMethods.RECT();
if (NativeMethods.GetWindowRect(hWnd, ref rect))
{
Size size = new Size(rect.Right - rect.Left,
rect.Bottom - rect.Top);
// Get information about the screen
using (Graphics browserGraphics = Graphics.FromHwnd(hWnd))
// apply that info to a bitmap...
using (Bitmap screenshot = new Bitmap(size.Width, size.Height,
browserGraphics))
// and create an Graphics to manipulate that bitmap.
using (Graphics imageGraphics = Graphics.FromImage(screenshot))
{
int hWndX = rect.Left;
int hWndY = rect.Top;
imageGraphics.CopyFromScreen(hWndX, hWndY, 0, 0, size);
screenshot.Save(filename, ImageFormat.Bmp);
success = true;
}
}
// otherwise, fails.
return success;
}
}