Hi all am creating an message application but as soon as the app snatch a picture from my webcam it starts showing a window to choice a camera know its only one camera installed
[DllImport("user32", EntryPoint = "SendMessage")]
static extern int SendMessage(int hWnd, uint Msg, int wParam, int lParam);
[DllImport("avicap32.dll", EntryPoint = "capCreateCaptureWindowA")]
static extern int capCreateCaptureWindowA(string lpszWindowName, int dwStyle,
int X, int Y, int nWidth, int nHeight, int hwndParent, int nID);
const int WM_CAP_CONNECT = 1034;
const int WM_CAP_DISCONNECT = 1035;
const int WM_CAP_COPY = 1054;
const int WM_CAP_GET_FRAME = 1084;
This api works on windows xp with a service application so i created service app which pipe communicate with the appliaction and transfer the picture in bytes but note it only works on windows xp
how can i catch a webcam picture without this window am using some api in windows vista,7,8
Thanks B.
The API you are referring to (Video for Windows) is not supposed to operate without a window. The window however does not need to be visible, and you can move it out of work area too. It does not have to paint actually captured video as well, the window purpose is to communicate with the API. So it is usable in Window 7 too, provided of course that you have a well operating driver for these operating systems as well.
Other APIs you might want to look at are DirectShow and Media Foundation. DirectShow is the richest and best compatible throughout versions of Windows API, and you can do the task mentioned in the subject (capture without showing). From C# you typically work with it via DirectShow.NET library/binding and it has decent samples to look at on the website.
Related
You know when you right-click the desktop and there's a "Sort by" option that allows you to sort the icons by "Name", "Size", "Item Type", or "Date Modified"? Well, I want to find a way to sort the desktop's icons with a push of a button.
I saw a similar question being asked here on stackoverflow but it's old and the code didn't work for me. The link to the question is: Arranging desktop icons with C# . I'm trying to achieve this in Windows 10.
There was a comment on there that said that the LVM_* and LVA_* values are stored in the commctrl.h file which comes with the SDK. I couldn't find that file for some reason.
Here's what i'm using:
//sort desktop
public const int LVM_ARRANGE = 4118;
public const int LVM_ALIGNLEFT = 1;
[DllImport("user32.dll", CharSet = CharSet.Auto)]
public static extern IntPtr GetDesktopWindow();
[DllImport("user32.dll")]
public static extern int SendMessage(IntPtr hWnd, uint Msg, int wParam, int lParam);
//end of sort desktop
private void organizeBtn_Click(object sender, EventArgs e)
{
var DesktopHandle = GetDesktopWindow();
MessageBox.Show(GetDesktopWindow().ToString());
SendMessage(GetDesktopWindow(), LVM_ARRANGE, LVM_ALIGNLEFT, 0);
}
I've been digging for info or some sort of direction about this topic, especially regarding windows 10, but I can't find much. Please help?
In Windows 10, the desktop (not tile world!) is still a SysListView32, but the GetDesktopWindow API call will return the handle of its grandparent, a Progman window - reminiscence of the ancient "Program Manager" of Windows 3.0. Then there is a shim of the SHELLDLL_DefView class, and below that you find buried the listview you're after.
Use the information from this answer to move down from the shell window to the folder view, which you can eventually send the LVM_ARRANGE message.
This is a brittle approach, as it relies on undocumented properties of the operating system, which may change at any time with updates or new versions. It will probably break also when a user uses a slideshow as desktop background, because Windows then rearranges the desktop window stack. Hack to deal with this here.
Another approach which is documented and less likely to break in future versions, with the downside of involving COM and a nightmare from C#, is via the IFolderView of shell automation, two relevant finds here and here.
I develop C# .Net CF applications for a Win CE device, and am having problems getting the speaker volume change to affect actual volume when playing sound.
The interface I use is:
int waveOutSetVolume(IntPtr hMod, UInt32 dwVolume);
int PlaySound(string szSound, IntPtr hMod, int flags);
The code I use worked well with our old device which had the following setup:
AC'97 Audio codec, Windows CE 5, .Net CF 2.0.
However, on the new device the sound is played but I'm not able to change the volume. The setup is as follows:
HDA Audio codec, Windows CE 6, .Net CF 3.5.
I am uncertain whether this problem is within the Windows CE 6 OS image (e.g. missing/incorrect audio driver), or if I use the incorrect interface in my C# code.
Any help and ideas are most welcome!
Thanks,
Karl
Additional details:
Code:
public unsafe int SetVolume(int newVolumeInPercent)
{
UInt32 newVol = (UInt32)((double)(newVolumeInPercent * ushort.MaxValue) / 100.0);
newVol = newVol + (newVol << 16);
int resultSetVolume = waveOutSetVolume(IntPtr.Zero, newVol);
return (int)Math.Round((double)resultSetVolume * 100 / ushort.MaxValue);
}
public void playSound(string soundFile)
{
PlaySound(soundFile, IntPtr.Zero, (int)(Flags.SND_ASYNC | Flags.SND_FILENAME));
}
[DllImport("CoreDll.dll")]
private extern static int waveOutSetVolume(IntPtr hMod, UInt32 dwVolume);
[DllImport("CoreDll.dll", EntryPoint = "PlaySound", SetLastError = true)]
private extern static int PlaySound(string szSound, IntPtr hMod, int flags);
private enum Flags
{
SND_ASYNC = 0x0001,
SND_FILENAME = 0x00020000,
}
As you see in the code, I use the argument percentage volume for both the left and right channel.
Using Windows CE Remote Process Viewer, I can see that the audio driver (i.e. "jwavehda.dll") is loaded. Also the "waveapi.dll" (generic Window wave api?) is loaded.
I do get sound when tapping the screen, and using the "PlaySound" function I am able to play a wave file. The only problem is that I cannot affect the volume.
Thanks!
I'd need to see your calling code (and your p/invoke declaration here are incomplete as well) to be sure. Are you aware that the waveOutSetVolume dwVolume is split into two words, the upper work being the left channel volume and the lower work being the right channel volume? The value you're sending in might be affecting the behavior (you didn't show that part of your code).
The fact that the code worked on one platform but fails on another indicates to me that it's likely an OS/Platform issue. Do you get audio for things like screen taps or other system events? Do you have an audio control panel applet? Did you look for an audio driver in the registry to make sure it both exists in the OS and is also loaded?
I am developing an application for WINDOWS CE5.0 based device. It requires ORIYA language(INDIAN REGIONAL LANGUAGE) to be used completely. As visual studio use ENGLISH as standard language, please tell me how to proceed? I tried to copy the font in WINDOWS CE device's WINDOWS/FONTS folder but as i restart the device that font file disappears. I developed the application in c# and changed labels text into oriyaa in Development system. It looks fine on the development system but as i deployed it into device, All label text appears in ENGLISH. I dont know whats happening? I also need to set the LABEL.TEXT property in ORIYA language. Is it possible? How to take user input in ORIYA? Please help..... Thanks...
Not very sure as what you meant by browser but for the Forms you can go about using PrivateFontCollection
you can load the font from a folder in your app and then use
AddFontFile or AddMemoryFont as per your need. So now the Client can see the controls in the font you set and its available to it irrespective of its installed or not
I have used the following approach with English-based fonts, but I am not sure if it will work on your case. The original source of this approach is a nice post from Chris Tacke (SO user #ctacke) with some modifications.
[DllImport("coredll.dll")]
private static extern int AddFontResource(string lpszFilename);
[DllImport("coredll.dll", SetLastError = true)]
private static extern int SendMessage(IntPtr hWnd, int wMsg, IntPtr wParam, IntPtr lParam);
static IntPtr HWND_BROADCAST = (IntPtr)0xFFFF;
const int WM_Fontchange = 0x001D;
private static void RegisterFont(string aFontPath, string aTargetFontPath)
{
IntPtr thir = (IntPtr)0;
IntPtr fourth = (IntPtr)0;
try
{
if (!System.IO.File.Exists(aTargetFontPath))
System.IO.File.Copy(aFontPath, aFontTargetPath);
}
catch { throw; }
int _Loaded = AddFontResource(aFontTargetPath);
if (_Loaded != 0)
SendMessage(HWND_BROADCAST, WM_Fontchange, thir, fourth);
}
Is there a way to change the Windows wallpaper using some new feature in .NET 4?
You can use SystemParametersInfo to set the desktop wallpaper. This should work consistently on all versions of windows that your app can run on, however will require some interop.
The following interop declarations are what you need
public const int SPI_SETDESKWALLPAPER = 20;
public const int SPIF_UPDATEINIFILE = 1;
public const int SPIF_SENDCHANGE = 2;
[DllImport("user32.dll", CharSet = CharSet.Auto, SetLastError = true)]
public static extern int SystemParametersInfo(
int uAction, int uParam, string lpvParam, int fuWinIni);
Which can be used like this to change the desktop wallpaper
SystemParametersInfo(
SPI_SETDESKWALLPAPER, 0, "filename.bmp",
SPIF_UPDATEINIFILE | SPIF_SENDCHANGE);
You set the wallpaper by updating the registry. Here's an article from 2006 explaining how to do it. The details may have changed with newer versions of Windows, but the concept should be the same. Framework version should be irrelevant.
http://blogs.msdn.com/coding4fun/archive/2006/10/31/912569.aspx
Note that SystemParametersInfo will even return true, if the specified file does not exist! (on Windows 8 at least)
Plus you must give the full path to the file, not just a relative path.
Also on windows 7 and above this will create a new theme, and will turn off picture shuffling of course.
How on earth can you control the volume of the sound played using SndPlayAsync on Windows Mobile 6??
It seems like no one knows! The documentation doesn't mention anything regarding it...
So either there's no way, or it is kept top secret...
In addition, I am aware of the possibility of using the Windows Media Player, but I rather not, if possible.
Thanks for any help!
Aviv.
My suggestion is:
[DllImport("coredll.dll", SetLastError = true)]
protected static extern int waveOutSetVolume(IntPtr device, uint volume);
[DllImport("coredll.dll", SetLastError = true)]
internal static extern int waveOutGetVolume(IntPtr device, ref int volume);
And then you can call methods:
int before;
uint maxVol = uint.MaxValue;
waveOutGetVolume(IntPtr.Zero, ref before);
waveOutSetVolume(IntPtr.Zero, maxVol);
//Do some playing
waveOutSetVolume(IntPtr.Zero, before);
You can debug for other values. This will set it to highest.
Hope it helps?
You need to use the mixer... API functions to set the master volume. Here is a code sample:
http://www.csharp-home.com/index/tiki-read_article.php?articleId=134
To use this code in your Windows Mobile application, you need to change "winmm.dll" to "coredll.dll". Also, these methods may not be supported in Windows Mobile, but I'm pretty sure they are.