Call Windows API functions in C #
For the call of the Windows system API function, it is sometimes essential in programming, and various programming languages specifies the way the calls and interfaces, the calling methods in the C # language are as follows (the following programming environment is Visual Studio .NET):
1. Add a new item to the project, open this class file, add a reference to the following namespace in the file header:
Using system.Runtime.InteropServices;
In the class definition body, add a reference to the API in a static call, and the API calls below this article are:
///
/// Open and close the CD tray.
///
[DLLIMPORT ("Winmm.dll", entrypoint = "mciSendstring", charset = charset.auto)]
Public Static Extern Int McIndString (String LPSTRCOMMAND, STRING LPSTRRRNSTRING, INT URETURNLENGTH, INT HWNDCALLBACK);
///
/// Display and hide the mouse pointer.
///
[DLLIMPORT ("User32.dll", entrypoint = "showcursor", charset = charset.Auto)]
Public Static Extern Int Showcursor (int bshow);
///
/// Empty the recycle station.
///
[DLLIMPORT ("shell32.dll", entrypoint = "shemptyrecyclebin", charset = charset.auto)]
Public Static Extern long writtyrecyclebin (INTPTR HWND, STRING PSZROOTPATH, Long Dwflags);
///
/// Open the browser
///
[DLLIMPORT ("shell32.dll", entrypoint = "shellexecute", charset = charset.auto)]
Public Static Extern int Shellexecute (INTPTR HWND, STRING LPOPERATION, STRING LPFILE, STRING LPPARES, STRING LPDIRECTORY, INT NSHOWCMD);
///
/// Maximum window, minimize windows, normal size window;
///
[DLLIMPORT ("User32.dll", entrypoint = "showwindow", charset = charset.auto)]
Public Static Extern Int ShowWindow (INTPTR HWND, INT NCMDSHOW);
2. After having the above file, you can call the above API in the event processing of your own form object, the method is as follows:
The following strreturn is a public variable of the String type, and Apicalls refers to the class name created in the first step.
Open CD tray: long lngreturn = apicalls.mcisendstring ("set cdaudio door open", strreturn, 127, 0);
Close CD tray:
Long lngreturn = apicalls.mcisendstring ("Set CDAUDIO DOOR CLOSED", STRRETURN, 127, 0);
Display the mouse pointer in the application form:
Apicalls.showcursor (1);
Hide mouse pointers in the application form:
Apicalls.showcursor (0);
Empty recycle bin:
Apicalls.ShemptyRecyclebin (form.activeform.handle, "", 0x00000000);
Open the browser window, TextBox1.text indicates the URL address to access:
Long lngreturn = apicalls.shellexecute (form.activeform.handle, "open", textbox1.text, ",", 1);
Maximize windows:
Apicalls.ShowWindow (Form.Activeform.handle, 3);
Minimize windows:
Apicalls.ShowWindow (Form.Activeform.handle, 2);
Restore normal size window:
Apicalls.ShowWindow (Form.Activeform.handle, 1);
