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Code example for SendInput in C++

I'm currently trying  to develop an application that can generate keystrokes into another existing application. I've read around a bit and found that SendInput() is probably the function I need to be using, yet I'm having some problems getting it working. I'm trying and make it work at a basic level and just send one keystroke of character 'a' to an open text file in notepad. Can someone please tell me what I'm doing wrong in my code and how to fix please?

#define _WIN32_WINNT 0x0501
#include <windows.h>
#include <iostream>

using namespace std;

void main()
{
char end;
HWND windowHandle = FindWindow(0, "test.txt - Notepad");
INPUT *key;
if(windowHandle == NULL)
 cout << "not found";
SetForegroundWindow(windowHandle);
Sleep(1000);

key = new INPUT;
key->type = INPUT_KEYBOARD;
key->ki.wVk = 41;
key->ki.dwFlags = 0;
key->ki.time = 0;
key->ki.wScan = 0;
key->ki.dwExtraInfo = 0;

SendInput(1,key,sizeof(key));

key->ki.dwExtraInfo = KEYEVENTF_KEYUP;

SendInput(1,key,sizeof(key));
cout << "key inputted";
cin >> end;
}

Thanks for your help.
0
daumont
Asked:
daumont
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1 Solution
 
AlexFMCommented:
You need to send key to Notepad edit area which is child of Notepad frame window, and not to Notepad frame itself. Use GetWindow to find child edit box from windowHandle parent. Use Spy++ to see windows hierarchy.
0
 
daumontAuthor Commented:
I have added and changed part of the code to:
HWND childWindow = GetWindow(windowHandle,GW_CHILD);
SetForeGroundWindow(childWindow);

I've also checked that childwindow handle matches the one in Spy++.
It still does not print anything into the notepad. Is using setforegroundwindow() the wrong way to set the focus on the application about to receive the input?
0
 
AlexFMCommented:
SendInput(1,key,sizeof(key));

replace with:


SendInput(1,key,sizeof(INPUT));

sizeof(key) is 4 sins key is pointer.

0
 
daumontAuthor Commented:
Excellent work!. thanks
0
 
DanielRDCommented:
Can I get the finished code for this example?
0

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