I am working on a project where I need to program for print operations from device.
It has WIN CE 6.0. I am using Visual Studio 2005 (MFC).
The printer can be any PCL-compatible printer.
Currently, to get printer DC, I am using CreateDC().
hPrinterDC = CreateDC(L"PCL.DLL", L"Any Name", L"LPT1", NULL);
Using this call I am able to print successfully.
Here I am passing DEVMODE specific input parameter as NULL. But for having finer control over these print operations, I need to pass DEVMODE information to CreateDC().
For that I am planning to make a call to CreateDC() as specified above to generate DEVMODE specific information in the registry. I can then read this DEVMODE data from registry into local variable, modify only necessary fields of this variable, and pass this variable to CreateDC() to get printer DC for actual print operations to follow.
I am avoiding direct initialization of DEVMODE struct, as I don't have enough information about certain fields of DEVMODE e.g. dmDriverExtra.
I need to know how can I safely read a struct like DEVMODE from registry? Any relative example will be really helpful.
Kind Regards,
Aftab
This is ancient, but just in case someone finds this still useful.
The DEVMODE contains private and public area, so allocating it with size equal to sizeof(DEVMODE) will exclude some settings. Proper way to initialize the DEVMODE is to query its default state using DocumentProperties() function. It returns number of bytes required when last parameter is set to zero.
Related
In WinSpool.h I can enumerate all the printers using the EnumPrinters function, but I cannot find out how to rename an existing printer?
You can use the SetPrinter function to rename a printer.
You would set the Level parameter to 2 and the pPrinter parameter would point to a PRINTER_INFO_2 structure. The PRINTER_INFO_2::pPrinterName field lets you change the printer name.
Note that the docs for SetPrinter say:
To modify the current printer settings, call the GetPrinter function
to retrieve the current settings into a PRINTER_INFO_2 structure,
modify the members of that structure as necessary, and then call
SetPrinter.
So you would need to call GetPrinter with a properly initialized structure first, before modifying the name and calling SetPrinter.
How to obtain the content and the main parameters of devices using registry section HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Enum?
Well, I need to scan registry tree, containing ..\Enum\{SomeID}\{OneMoreID}\{MyDearValue}, which should contain some description, i.e. "KINGSTON 100500TB Flash of God". And the main question is: how to obtain all of this string descriptions, using WinAPI and C++?
Use the Win32 Registry functions.
http://msdn.microsoft.com/en-us/library/windows/desktop/ms724875(v=vs.85).aspx
Is my code correct? It seems can compile but does not work properly..
CString testing = _T(" --url=") + cstring + _T(" --out=%USERPROFILE%\\snapshot.png");
I want to point it to user's folder..but still cannot work.
The answer is that you don't use environment variables at all. Rather, you use the shell functions specifically designed to retrieve the path of special folders.
On Windows Vista and later, that function is SHGetKnownFolderPath. It takes KNOWNFOLDERID values to identify the folder whose path you wish to retrieve. In your case, that would be FOLDERID_Profile.
If you need to target earlier versions of Windows (such as XP), you will need to use the SHGetSpecialFolderPath function, instead. It takes a CSIDL value identifying the folder whose path you wish to retrieve. Again, in your case, that would be CSIDL_PROFILE.
Of course, you should never store data directly in the user's profile folder. So hopefully the bit of code that you've shown is for demonstration purposes only. Applications should only create files in the specific locations under the user profile folder, designed for application data storage.
These locations are CSIDL_APPDATA or CSIDL_LOCAL_APPDATA. If you are creating data that the user should be able to modify and should treat as his/her own, then it would be appropriate to store that data in the user's documents folder (CSIDL_MYDOCUMENTS).
More usage information is available in my answer here.
Sample code:
TCHAR szFolderPath[MAX_PATH];
if (!SHGetSpecialFolderPath(NULL, szFolderPath, CSIDL_APPDATA, FALSE))
{
// Uh-oh! An error occurred; handle it.
}
Or, using MFC's CString class:
CString buffer;
BOOL bRet = SHGetSpecialFolderPath(NULL, buffer.GetBuffer(MAX_PATH), CSIDL_APPDATA, FALSE);
buffer.ReleaseBuffer();
if (!bRet)
{
// Uh-oh! An error occurred; handle it.
}
As Cody suggested, it's better to use the SHGetSpecialFolderPath function. However, you could use the GetEnvironmentVariable function to get that and other variables set in the system.
TCHAR szBuf[MAX_PATH] = {0};
::GetEnvironmentVariable(_T( "USERPROFILE" ), szBuf, MAX_PATH);
I'm learning how to write a scriptable ActiveX control. My goal is to have a tiny control that can check to see if something is installed on the system. What I've done so far is:
Create a MFC ActiveX control project in VS2008
Add some 'safe for scripting' bits that I found here.
Extend the IDL to provide my "IsInstalled" method, which for now returns TRUE unconditionally (but will later read some keys from the registry.)
Build the control and run regsvr32 on it. I verified that it does show up in HKEY_CLASSES_ROOT, and when I instantiate the object, the IE Developer Tools "Locals" pane shows that the object is of type _D[my plugin name]. Not only that, but my IsInstalled() method shows up underneath that object.
However, when I call IsInstalled(), I just can't get it to work:
JScript Debugger - Breaking on JScript runtime error -(n http://img138.imageshack.us/img138/1586/whycomwhy.png
I'm at a loss. I've also tried making IsInstalled a property instead of a method, using VARIANT_BOOL instead of boolean instead of BOOL in the IDL, you name it.
Here's the relevant excerpts of code.
The header:
afx_msg VARIANT_BOOL IsInstalled();
The implementation:
afx_msg VARIANT_BOOL
CMyAXCtrl::IsInstalled()
{
return TRUE;
}
The dispatch map:
BEGIN_DISPATCH_MAP(CMyAXCtrl, COleControl)
DISP_FUNCTION_ID(CMyAXCtrl, "IsInstalled", dispidIsInstalled, IsInstalled, VT_BOOL, VTS_NONE)
END_DISPATCH_MAP()
The dispatch part of the IDL:
[ uuid(6B662202-CF13-4144-AA33-C3FEE9C2C962),
helpstring("Dispatch interface for My Control")]
dispinterface _Daxplugin
{
properties:
methods:
[id(1)] VARIANT_BOOL IsInstalled();
};
If there's any other relevant bits of code I should provide, let me know. But I'm stumped here. Thank you in advance!
You almost certainly have the wrong prototype for a scriptable function. OLE Automation for scripting languages tends to rely on returning a HRESULT then using an out parameter for the actual return code.
So change it to
[id(1)] HRESULT IsInstalled(VARIANT_BOOL* p);
Also TRUE != VARIANT_TRUE, you must return VARIANT_TRUE which is equal to -1 instead of 1.
Hope some of that actually helps, but without the actual error I might be mistaken :)
You could mark your control as save for scripting by implementing IObjectSafety or by marking the Object as save while registering it (as supposed by the link you provided).
Have you run regsvr32 after adding the code to mark it save for scripting?
You can check the registry if your control has the safe for scripting bits set.
If the bits are set you will find the two keys {7DD95802-9882-11CF-9FA9-00AA006C42C4} (Safe for Initialization)
{7DD95801-9882-11CF-9FA9-00AA006C42C4}(Safe For Scripting) as subkeys of ImplementedCategories in your object.
I would suggest to implement IObjectSafety since it doesn't depend on your class to register itself.
I would like to know the cleanest way of registering a file extension with my C++ application so that when a data file associated with my program is double clicked, the application is opened and the filename is passed as a parameter to the application.
Currently, I do this through my wix installer, but there are some instances where the application will not be installed on ths user's computer, so I also need the option of creating the registry key through the application.
Additionally, will this also mean that if the application is removed, unused entries in the registry will be left lying around?
Your basic overview of the process is found in this MSDN article. The key parts are at the bottom of the list:
Register the ProgID
A ProgID (essentially, the file type registry key) is what contains your important file type properties, such as icon, description, and context menu items including applications used when the file is double clicked. Many extensions may have the same file type. That mapping is done in the next step:
Register the file name extension for the file type
Here, you set a registry value for your extension, setting that extension's file type to the ProgID you created in the previous step.
The minimum amount of work required to get a file to open with your application is setting/creating two registry keys. In this example .reg file, I create a file type (blergcorp.blergapp.v1) and associate a file extension (.blerg) with it.
Windows Registry Editor Version 5.00
[HKEY_CURRENT_USER\Software\Classes\blergcorp.blergapp.v1\shell\open\command]
#="c:\path\to\app.exe \"%1\""
[HKEY_CURRENT_USER\Software\Classes\.blerg]
#="blergcorp.blergapp.v1"
Now, you probably want to accomplish this programmatically. To be absolutely kosher, you could check for the existence of these keys, and change your program behavior accordingly, especially if you're assuming control of some common file extension. However, the goal can be accomplished by setting those two keys using the SetValue function.
I'm not positive of the exact C++ syntax, but in C# the syntax looks something like this:
Registry.SetValue(#"HKEY_CURRENT_USER\Software\Classes\blergcorp.blergapp.v1\shell\open\command", null, #"c:\path\to\app.exe \"%1\"");
Registry.SetValue(#"HKEY_CURRENT_USER\Software\Classes\.blerg", null, "blergcorp.blergapp.v1");
Of course you could manually open each sub key, manually create the ProgID and extension subkey, and then set the key value, but a nice thing about the SetValue function is that if the keys or values don't exist, they will automatically be created. Very handy.
Now, a quick word about which hive to use. Many file association examples online, including ones on MSDN, show these keys being set in HKEY_CLASSES_ROOT. I don't recommend doing this. That hive is a merged, virtual view of HKEY_LOCAL_MACHINE\Software\Classes (the system defaults) and HKEY_CURRENT_USER\Software\Classes (the per-user settings), and writes to any subkey in the hive are redirected to the same key in HKEY_LOCAL_MACHINE\Software\Classes. Now, there's no direct problem doing this, but you may run into this issue: If you write to HKCR (redirected to HKLM), and the user has specified the same keys with different values in HKCU, the HKCU values will take precedence. Therefore, your writes will succeed but you won't see any change, because HKEY_CURRENT_USER settings take precedence over HKEY_LOCAL_MACHINE settings.
Therefore, you should take this into consideration when designing your application. Now, on the flip side, you can write to only HKEY_CURRENT_USER, as my examples here show. However, that file association setting will only be loaded for the current user, and if your application has been installed for all users, your application won't launch when that other user opens the file in Windows.
That should be a decent primer for what you want to do. For further reading I suggest
Best Practices for File Association
File Types and File Association, especially
How File Associations Work
And see also my similar answer to a similar question:
Associating file extensions with a program
This is a two step process:
1. Define a program that would take care of extension: (unless you want to use existing one)
1.1 create a key in "HKCU\\Software\\Classes\\" for example
"Software\\Classes\\YourProgramName.file.ext"
1.2 create subkey "Software\\Classes\\YourProgramName.file.ext\\DefaultIcon"
1.2.1 set default value ("") to your application full path to get
icon from resources
1.3 create a subkey "Software\\Classes\\YourProgramName.file.ext\\Shell\\OperationName\\Command"
OperationName = for example Open, Print or Other
1.3.1 set default value ("") to your application full path +optional runtime params (filename)
2.Associate file extension with program.
2.1 create a key HKCU\\Software\\Classes\\.ext - here goes your extension
2.2 set default value to the program definition key
("YourProgramName.file.ext")
Below is part of the program written in c# which associate file extension. It is not c++ but i think it is simple enought to explain itself and AFAIK it is verv simmilar if not identical to the code in c++
1.
RegistryKey keyPFCTExt0 = Registry.CurrentUser.OpenSubKey("Software\\Classes\\PFCT.file.enc", true);
if (keyPFCTExt0 == null)
{
keyPFCTExt0 = Registry.CurrentUser.CreateSubKey("Software\\Classes\\PFCT.file.enc");
keyPFCTExt0.CreateSubKey("DefaultIcon");
RegistryKey keyPFCTExt0ext = Registry.CurrentUser.OpenSubKey("Software\\Classes\\PFCT.file.enc\\DefaultIcon", true);
keyPFCTExt0ext.SetValue("", Application.ExecutablePath +",0");
keyPFCTExt0ext.Close();
keyPFCTExt0.CreateSubKey("Shell\\PFCT_Decrypt\\Command");
}
keyPFCTExt0.SetValue("", "PFCT.file.enc");
keyPFCTExt0.Close();
2.
RegistryKey keyPFCTExt1 = Registry.CurrentUser.OpenSubKey("Software\\Classes\\PFCT.file.enc\\Shell\\PFCT_Decrypt\\Command", true);
if (keyPFCTExt1 == null)
keyPFCTExt1 = Registry.CurrentUser.CreateSubKey("Software\\Classes\\PFCT.file.enc\\Shell\\PFCT_Decrypt\\Command");
keyPFCTExt1.SetValue("", Application.ExecutablePath + " !d %1"); //!d %1 are optional params, here !d string and full file path
keyPFCTExt1.Close();
I don't know why people keep saying that HKEY_CURRENT_USER\Software\Classes\<.ext>'s Default value (which will redirect you into another (software-created) class.
It does work, but it will be overridden by
HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Explorer\FileExts\<.ext>\UserChoice
And I believe Microsoft recommends the second practice- because it's what the built-in "open with" is doing. The value of Progid" key is equal to default value of HKEY_CURRENT_USER\Software\Classes\<.ext> in this case.
I found the following while trying to manipulate associations using C#:
hkcu\software\microsoft\windows\currentVersion\explorer\fileexts.reg\userchoice -> for user specific settings. The values in the openWithProgIds
key point to the keys in the hkcr.
hkcr\xfile\shell\open\muiVerb value or hkcr\xfile\shell\open\command\default value -> affects open handler. This is the value that contains the path to a program.
hkcr\ .x -> affects context menu (new x) among other things related to the menus.
I don't know the C++ code, but given these info you must be able to manipulate the registry using the registry API.