C # Calling the Windows API sample

One, callWindowsApi.
The Windows API methods for C # downgrade are as follows:
1. Introduction of namespaces: Using System.Runtime.InteropServices;
2, the reference needs to use the method, format: [DllImport ("DLL file")] method declaration;
[DllImport ("User32.dll")]private static extern bool ShowWindow (IntPtr hWnd, int ncmdshow);
[DllImport ("User32.dll")]private static extern bool SetForegroundWindow (IntPtr hWnd);
[DllImport ("User32.dll")]private static extern IntPtr FindWindow (string lpclassname,string lpwindowname);
[DllImport ("User32.dll")]private static extern int SendMessage (IntPtr hwnd,int msg,int wparam,int lParam);
[DllImport ("User32.dll")]private static extern bool Setcursorpos (int X, int Y);
[DllImport ("User32.dll")]private static extern void mouse_event (int dwFlags, int dx, int dy, int dwdata, int dwextrainfo);
[DllImport ("User32.dll")]private static extern void keybd_event (byte bvk, byte bscan, uint dwFlags, uint dwextrainfo);
[DllImport ("User32.dll")]private static extern bool SetWindowPos (IntPtr hWnd, IntPtr hwndlnsertafter, int X, int Y, int cx , int cy, uint Flags);
ShowWindow parameters
Private Const int SW_SHOWNORMAL = 1;
Private Const int sw_restore = 9;
Private Const int sw_shownoactivate = 4;
SendMessage parameters
Private Const int WM_KEYDOWN = 0X100;
Private Const int WM_KEYUP = 0X101;
Private Const int WM_SYSCHAR = 0x106;
Private Const int wm_syskeyup = 0x105;
Private Const int wm_syskeydown = 0x104;
Private Const int WM_CHAR = 0X102;

Second, find the target window
1), the handle is obtained according to the title of the window
IntPtr myintptr = FindWindow (null, "window name"); Null is the class name, can be obtained with Spy + +, or it can be empty
ShowWindow (Myintptr, Sw_restore); Restore a window
SetForegroundWindow (MYINTPTR); If there is no ShowWindow, this method cannot set the minimized window
2), traverse all windows to get handle
1 Define delegate method callback, Enumerate window API (EnumWindows), Get Window name API (GETWINDOWTEXTW) and Get window class name API (Getclassnamew)
Public delegate bool CallBack (int hwnd, int lParam);
[DllImport ("user32")]public static extern int EnumWindows (CallBack x, int y);
[DllImport ("User32.dll")]private static extern int getwindowtextw (IntPtr hWnd, [MarshalAs (UNMANAGEDTYPE.LPWSTR)] StringBuilder lpstring, int nmaxcount);
[DllImport ("User32.dll")]private static extern int Getclassnamew (IntPtr hWnd, [MarshalAs (UNMANAGEDTYPE.LPWSTR)] StringBuilder lpstring, int nmaxcount);
2 Calling EnumWindows Traversal window
CallBack mycallback = new CallBack (Recall);
EnumWindows (mycallback, 0);
3 callback method recall
public bool Recall (int hwnd, int lParam)
{
StringBuilder sb = new StringBuilder (256);
IntPtr PW = new IntPtr (HWND);

GETWINDOWTEXTW (PW,SB,SB. capacity); Get the window name and save it in strname
String strName = sb. ToString ();

Getclassnamew (PW,SB,SB. capacity); Get the window class name and save it in strclass
String strclass = sb. ToString ();

if (Strname.indexof ("Window name keyword") >= 0 && strclass.indexof ("Class name keyword") >= 0)
{
return false; Returns false aborts EnumWindows traversal
}
Else
{
return true; Returns true to continue enumwindows traversal
}
}
3), open the window to get the handle
1 Define Settings active window API (SetActiveWindow), set foreground window API (SetForegroundWindow)
[DllImport ("user32.dll")]static extern IntPtr SetActiveWindow (IntPtr hWnd);
[DllImport ("User32.dll")] [Return:marshalas (Unmanagedtype.bool)]static extern Bool SetForegroundWindow (IntPtr hWnd);
2 Open Window
Process proc = Process.Start (@ "target program path");
SetActiveWindow (Proc. Mainwindowhandle);
SetForegroundWindow (Proc. Mainwindowhandle);

Iii. entering data into a specified window
1 sending data to a window using the Send Message API (SendMessage)
Inputstr (Myintptr, _gameid); Enter the game ID
SendMessage (Myintptr, Wm_syskeydown, 0X09, 0); Enter tab (0X09)
SendMessage (Myintptr, Wm_syskeyup, 0X09, 0);
Inputstr (Myintptr, _gamepass); Enter the game password
SendMessage (Myintptr, Wm_syskeydown, 0X0D, 0); Enter Enter (0x0d)
SendMessage (Myintptr, Wm_syskeyup, 0X0D, 0);

<summary>
Send a string
</summary>
<param name= "myintptr" > Window handles </param>
<param name= "Input" > String </param>
public void Inputstr (IntPtr myintptr, String Input)
{
byte[] ch = (ASCIIEncoding.ASCII.GetBytes (Input));
for (int i = 0; i < Ch. Length; i++)
{
SendMessage (PW, WM_CHAR, ch, 0);
}
}
2 using mouse and keyboard to simulate sending data to a window
SetWindowPos (PW, (INTPTR) ( -1), 0, 0, 0, 0, 0x0040 | 0x0001); Set Window Position
Setcursorpos (476, 177); Setting the mouse position
Mouse_event (0x0002, 0, 0, 0, 0); Simulate mouse down action
Mouse_event (0x0004, 0, 0, 0, 0); Simulate Mouse release action
Sendkeys.send (_gameid); Analog keyboard input Game ID
Sendkeys.send ("{tab}"); Analog Keyboard Input Tab
Sendkeys.send (_gamepass); Analog keyboard Input Game password
Sendkeys.send ("{ENTER}"); Analog keyboard Input Enter

Another: The Keybd_event method is mentioned above, the usage and the Mouse_event method are similar, the function and the Sendkeys.send same.

C # Calling the Windows API sample