![\"npm](\"https:\/\/devblogs.microsoft.com\/cse\/wp-content\/uploads\/sites\/55\/2020\/03\/2015-11-09-NodeJS-Windows-Registry-npm.jpg\")
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Overview of the Solution<\/h2>\n
We partnered with GitHub, the maintainer of Electron, and Visual Studio Code, to enable registry operations and file associations for Node application on Windows. As a result of our hackathon, there is now a NPM module for Windows Registry<\/a> you can include in your application to do just that.<\/p>\n This library interacts with native Windows APIs. We leveraged the following node modules to enable Node.js application to communicate with Windows interfaces:<\/p>\n We leveraged the following Windows DLLs to communicate with Windows APIs.<\/p>\n Let\u2019s dive into the code!<\/p>\n We created a Node wrapper adv_api.js<\/a> for In C++, the follow example illustrates the use of In our Node.js wrapper, we used the Similarly, we created a Node wrapper shell32.js<\/a> for In C++, the following example illustrates the use of In our Node.js wrapper, we used the As you can see, in order to replicate the exact Windows API call in JavaScript, we needed to create the same function with the exact inputs and outputs of the same data type as the Windows native data types.<\/p>\n For example, let\u2019s look at how we defined the data types for the In C++, here is the definition of the With the above definition, In C++, this is the definition of the In our Node.js wrapper windef.js<\/a>, we needed to create the same For each struct member, we looked up its data type and its size from the Windows Data Types reference<\/a>, then created the same data type with the same properties in types.js<\/a>. We leveraged the Interact with Windows APIs<\/h3>\n
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Creating Node Wrappers for Windows APIs<\/h3>\n
Advapi32.dll<\/code> to support basic registry manipulation. Using the ffi<\/code> node module, we can load Advapi32.dll<\/code>. Then for each Windows API we wanted to call, we created a Javascript API with the expected inputs and outputs.<\/p>\nRegOpenCurrentUser<\/code>, which is used to retrieve a handle to the HKEY_CURRENT_USER key for the user that the current thread is impersonating.<\/p>\nHKEY keyCurrentUser;\r\nlResult = RegOpenCurrentUser(KEY_READ, &keyCurrentUser);\r\n<\/code><\/pre>\n<\/div>\nffi<\/code> node module to load Advapi32.dll<\/code>. Then we defined the RegOpenCurrentUser<\/code> API and other Registry related APIs with their expected inputs and outputs.<\/p>\nvar<\/span> ffi<\/span> =<\/span> require<\/span>(<\/span>'ffi'<\/span>);<\/span>\r\nvar<\/span> advApi<\/span> =<\/span> ffi<\/span>.<\/span>Library<\/span>(<\/span>'Advapi32'<\/span>,<\/span> {<\/span>\r\n RegOpenCurrentUser<\/span>:<\/span> [<\/span>'uint64'<\/span>,<\/span> [<\/span>types<\/span>.<\/span>REGSAM<\/span>,<\/span> types<\/span>.<\/span>PHKEY<\/span>]],<\/span>\r\n RegQueryValueExA<\/span>:<\/span> [<\/span>'uint64'<\/span>,<\/span> [<\/span>types<\/span>.<\/span>HKEY<\/span>,<\/span> 'string'<\/span>,<\/span> 'pointer'<\/span>,<\/span> types<\/span>.<\/span>LPDWORD<\/span>,<\/span> types<\/span>.<\/span>LPBYTE<\/span>,<\/span> types<\/span>.<\/span>LPDWORD<\/span>]],<\/span>\r\n ...<\/span>\r\n\r\n});<\/span>\r\n<\/code><\/pre>\n<\/div>\nShell32.dll<\/code>, which is used to launch a process on Windows.<\/p>\nShellExecuteEx<\/code> to launch an application:<\/p>\nBOOL result = ShellExecuteExA(&ShExecInfo);\r\n<\/code><\/pre>\n<\/div>\nffi<\/code> node module to load Shell32.dll<\/code>, then we defined the ShellExecuteExA<\/code> API with its expected input and output.<\/p>\nvar<\/span> ffi<\/span> =<\/span> require<\/span>(<\/span>'ffi'<\/span>);<\/span>\r\nvar<\/span> shell32<\/span> =<\/span> ffi<\/span>.<\/span>Library<\/span>(<\/span>'Shell32'<\/span>,<\/span> {<\/span>\r\n\r\n ShellExecuteExA<\/span>:<\/span> [<\/span>'bool'<\/span>,<\/span> [<\/span>SHELLEXECUTEINFOPtr<\/span>]]<\/span>\r\n});<\/span>\r\n<\/code><\/pre>\n<\/div>\nCreate Windows Data Types in JavaScript<\/h3>\n
ShellExecuteExA<\/code> function.<\/p>\nShellExecuteEx<\/code> function:<\/p>\nBOOL ShellExecuteExA(\r\n _Inout_ SHELLEXECUTEINFO *pExecInfo\r\n);\r\n<\/code><\/pre>\n<\/div>\nShellExecuteEx<\/code> expects a parameter of the type SHELLEXECUTEINFO*<\/code>, which is a pointer to a SHELLEXECUTEINFO<\/code> structure that contains and receives information about the application being executed. It also has a return value of type BOOL<\/code>, which represents the result of executing this call.<\/p>\nSHELLEXECUTEINFO<\/code> structure.<\/p>\ntypedef struct _SHELLEXECUTEINFO {\r\n DWORD cbSize;\r\n ULONG fMask;\r\n HWND hwnd;\r\n LPCTSTR lpVerb;\r\n LPCTSTR lpFile;\r\n LPCTSTR lpParameters;\r\n LPCTSTR lpDirectory;\r\n int nShow;\r\n HINSTANCE hInstApp;\r\n LPVOID lpIDList;\r\n LPCTSTR lpClass;\r\n HKEY hkeyClass;\r\n DWORD dwHotKey;\r\n union {\r\n HANDLE hIcon;\r\n HANDLE hMonitor;\r\n } DUMMYUNIONNAME;\r\n HANDLE hProcess;\r\n} SHELLEXECUTEINFO, *LPSHELLEXECUTEINFO;\r\n<\/code><\/pre>\n<\/div>\nSHELLEXECUTEINFO<\/code> struct. Luckily, we had ref<\/code>, ref struct<\/code>, and ref union<\/code> node modules to help us create the same struct in Javascript.<\/p>\nSHELLEXECUTEINFO<\/span>:<\/span> struct<\/span>({<\/span>\r\n cbSize<\/span>:<\/span> types<\/span>.<\/span>DWORD<\/span>,<\/span>\r\n fMask<\/span>:<\/span> types<\/span>.<\/span>ULONG<\/span>,<\/span>\r\n hwnd<\/span>:<\/span> types<\/span>.<\/span>HWND<\/span>,<\/span>\r\n lpVerb<\/span>:<\/span> types<\/span>.<\/span>STRING<\/span>,<\/span>\r\n lpFile<\/span>:<\/span> types<\/span>.<\/span>STRING<\/span>,<\/span>\r\n lpParameters<\/span>:<\/span> types<\/span>.<\/span>STRING<\/span>,<\/span>\r\n lpDirectory<\/span>:<\/span> types<\/span>.<\/span>STRING<\/span>,<\/span>\r\n nShow<\/span>:<\/span> types<\/span>.<\/span>INT<\/span>,<\/span>\r\n hInstApp<\/span>:<\/span> types<\/span>.<\/span>HINSTANCE<\/span>,<\/span>\r\n lpIDList<\/span>:<\/span> types<\/span>.<\/span>LPVOID<\/span>,<\/span>\r\n lpClass<\/span>:<\/span> types<\/span>.<\/span>STRING<\/span>,<\/span>\r\n hkeyClass<\/span>:<\/span> types<\/span>.<\/span>HKEY<\/span>,<\/span>\r\n dwHotKey<\/span>:<\/span> types<\/span>.<\/span>DWORD<\/span>,<\/span>\r\n DUMMYUNIONNAME<\/span>:<\/span> DUMMYUNIONNAME<\/span>,<\/span>\r\n hProcess<\/span>:<\/span> types<\/span>.<\/span>HANDLE<\/span>\r\n })<\/span>\r\n<\/code><\/pre>\n<\/div>\nref<\/code> node module to create types.<\/p>\n