C # WindowsAPI,

C # WindowsAPI,

Windows is a powerful operating system. It also provides developers with a large number of system APIs to help developers develop Windows system software.

For some Windows APIs, C # can be called directly.

1. the icon of the .exe application is obtained.

1 [DllImport ("shell32.DLL", EntryPoint = "ExtractAssociatedIcon")] 2 private static extern int ExtractAssociatedIconA (int hInst, string lpIconPath, ref int lpiIcon); // declare function 3 System. intPtr thisHandle; 4 public System. drawing. icon GetIco (string filePath) // filePath is the file path to be obtained. The ico format file 5 {6 int RefInt = 0; 7 thisHandle = new IntPtr (ExtractAssociatedIconA (0, filePath, ref RefInt); 8 return System. drawing. icon. fromHandle (thisHandle); 9}

2. Obtain hard disk Information

Public string GetComputorInformation () {StringBuilder mStringBuilder = new StringBuilder (); DriveInfo [] myAllDrivers = DriveInfo. getDrives (); try {foreach (DriveInfo myDrive in myAllDrivers) {if (myDrive. isReady) {mStringBuilder. append ("disk drive letter:"); mStringBuilder. appendLine (myDrive. name); mStringBuilder. append ("disk volume label:"); mStringBuilder. appendLine (myDrive. volumeLabel); mStringBuilder. append ("disk type:"); mStringBuilder. appendLine (myDrive. driveType. toString (); mStringBuilder. append ("disk format:"); mStringBuilder. appendLine (myDrive. driveFormat); mStringBuilder. append ("disk size:"); decimal resultmyDrive = Math. round (decimal) myDrive. totalSize/1024/1024/1024, 2); mStringBuilder. appendLine (resultmyDrive "GB"); mStringBuilder. append ("available space:"); decimal resultAvailableFreeSpace = Math. round (decimal) myDrive. availableFreeSpace/1024/1024/1024, 2); mStringBuilder. appendLine (resultAvailableFreeSpace "GB"); mStringBuilder. append ("total available space (including Disk Quota):"); decimal resultTotalFreeSpace = Math. round (decimal) myDrive. totalFreeSpace/1024/1024/1024, 2); mStringBuilder. appendLine (resultTotalFreeSpace "GB"); mStringBuilder. appendLine ("-----------------------------------") ;}} catch (Exception ex) {throw ex;} return mStringBuilder. toString ();}

3. Start the program

// Obtain the Registry Startup location RegistryKey RKey = Registry. localMachine. openSubKey ("SOFTWARE \ Microsoft \ Windows \ CurrentVersion \ Run", true ); /// <summary> /// set boot start /// </summary> /// <param name = "path"/> public void StartRunApp (string path) {string strnewName = path. substring (path. lastIndexOf ("\") 1); // if (! File. exists (path) // determines whether the specified file has a return; if (RKey = null) {RKey = Registry. localMachine. createSubKey ("SOFTWARE \ Microsoft \ Windows \ CurrentVersion \ Run");} RKey. setValue (strnewName, path); // modify the registry, enable the program to run automatically at startup} // <summary> // cancel startup /// </summary> /// <param name = "path"/> public void ForbitStartRun (string path) {string strnewName = path. substring (path. lastIndexOf ("\") 1); // name of the key to be written to the Registry RKey. deleteValue (strnewName, false); // by modifying the registry, cancel the program to run automatically at startup}

4. System hotkey operation

[DllImport ("user32.dll")] // declare the api function public static extern bool RegisterHotKey (IntPtr hwnd, // window handle int id, // hotkey ID uint fsmodifiers, // hotkey modify option Keys vk // hotkey); [DllImport ("user32.dll")] // declare the api function public static extern bool UnregisterHotKey (IntPtr hwnd, // window handle int id // hotkey ID); public enum keymodifiers // key combination enumeration {none = 0, alt = 1, control = 2, shift = 4, windows = 8} private void processhotkey (Message m) // call this function {IntPtr id = m when you press the set key. WParam; // intptr indicates the platform-specific type of pointer or handle. // messagebox. show (id. tostring (); string sid = id. toString (); switch (sid) {case "100": break; case "200": break ;}} /// <summary> /// register the hotkey /// </summary> public void RegisterHotkey (IntPtr handle, int hotkeyID, uint fsmodifiers, Keys mKeys) {RegisterHotKey (handle, hotkeyID, fsmodifiers, mKeys );} /// <summary> /// uninstall the hotkey /// </summary> /// <param name = "handle"/> /// <param name = "hotkeyID" /> public void UnregisterHotkey (IntPtr handle, int hotkeyID) {UnregisterHotKey (handle, hotkeyID );}

5. system process operations

Public class GetProcess {bool isSuccess = false; [DllImport ("kernel32")] public static extern void GetWindowsDirectory (StringBuilder WinDir, int count); [DllImport ("kernel32")] public static extern void GetSystemDirectory (StringBuilder SysDir, int count); [DllImport ("kernel32")] public static extern void GetSystemInfo (ref CPU_INFO cpuinfo); [DllImport ("kernel32")] public static extern void GlobalMemoryStatus (ref MEMORY_INFO meminfo); [DllImport ("kernel32")] public static extern void GetSystemTime (ref SYSTEMTIME_INFO stinfo ); // define the CPU information structure [StructLayout (LayoutKind. sequential)] public struct CPU_INFO {public uint dwOemId; public uint dwPageSize; public uint lpMinimumApplicationAddress; public uint role; public uint dwProcessorType; public uint role; public uint dwProcessorLevel; public uint dwProcessorRevision;} // defines the memory information structure [StructLayout (LayoutKind. sequential)] public struct MEMORY_INFO {public uint dwLength; public uint dwMemoryLoad; public uint dwTotalPhys; public uint values; public uint dwTotalVirtual; public uint dwAvailVirtual ;} // define the system time information structure [StructLayout (LayoutKind. sequential)] public struct SYSTEMTIME_INFO {public ushort wYear; public ushort wMonth; public ushort week; public ushort wDay; public ushort wHour; public ushort wMinute; public ushort wSecond; public ushort second ;} public string GetSystemInformation () {MEMORY_INFO MemInfo = new MEMORY_INFO (); GlobalMemoryStatus (ref MemInfo); return MemInfo. dwMemoryLoad. toString ();} public string GetSystemCup () {CPU_INFO CpuInfo = new CPU_INFO (); GetSystemInfo (ref CpuInfo); return CpuInfo. dwProcessorType. toString () ;}/// <summary> /// obtain all processes currently /// </summary> /// <returns> </returns> public DataTable GetAllProcess () {DataTable mDataTable = new DataTable (); mDataTable. rows. clear (); mDataTable. columns. add ("ProcessID"); mDataTable. columns. add ("ProcessName"); mDataTable. columns. add ("Memory"); mDataTable. columns. add ("StartTime"); mDataTable. columns. add ("FileName"); mDataTable. columns. add ("ThreadNumber"); Process [] myProcess = Process. getProcesses (); foreach (Process p in myProcess) {DataRow mDataRow = mDataTable. newRow (); mDataRow [0] = p. id; mDataRow [1] = p. processName; mDataRow [2] = string. format ("{0 :##,## 0.00} KB", p. privateMemorySize64/1024); // some processes cannot obtain the start time and file name information, so try/catch; try {mDataRow [3] = string. format ("{0}", p. startTime); mDataRow [4] = p. mainModule. fileName; mDataRow [5] = p. threads. count;} catch {mDataRow [3] = ""; mDataRow [4] = "";} mDataTable. rows. add (mDataRow);} return mDataTable ;} /// <summary> /// end the process /// </summary> /// <param name = "processName"/>/// <returns> </returns> public bool KillProcess (string processName) {try {System. diagnostics. process [] process = System. diagnostics. process. getProcessesByName (processName); foreach (System. diagnostics. process p in process) {p. kill () ;}} catch {isSuccess = false;} return isSuccess ;}}

6. Change the window

public const int SE_SHUTDOWN_PRIVILEGE = 0x13;            [DllImport("user32.dll")]         public static extern IntPtr FindWindow(string lpClassName, string lpWindowName);            [DllImport("user32.dll")]         public static extern IntPtr SetParent(IntPtr hWndChild, IntPtr hWndNewParent);            [DllImport("user32.dll")]         public static extern bool SetWindowPos(IntPtr hWnd, int hWndInsertAfter, int X, int Y, int cx,             int cy, uint uFlags);