Hey there! I totally get where you're coming from—helping a family member simplify repetitive tasks is such a nice gesture, and it's totally doable with the Windows API even if you're new to C++. Let's walk through this step by step.

Core Approach: Use SendInput from windows.h #

You were on the right track with windows.h! The key API you need is SendInput—it's the modern, reliable way to simulate keyboard input on Windows (way better than the older keybd_event which is deprecated). Here's how to put it together:

Step 1: Basic Setup & Helper Functions #

First, we'll create simple helper functions to handle single key presses and typing full strings. These will make your main code clean and easy to follow.

#include <windows.h>
#include <string>

// Helper to press and release a single key
void PressKey(WORD keyCode) {
    INPUT input = {0};
    input.type = INPUT_KEYBOARD;
    input.ki.wVk = keyCode;

    // Press the key
    SendInput(1, &input, sizeof(INPUT));

    // Release the key
    input.ki.dwFlags = KEYEVENTF_KEYUP;
    SendInput(1, &input, sizeof(INPUT));
}

// Helper to type a full string (handles uppercase, symbols too!)
void TypeString(const std::string& text) {
    for (char c : text) {
        // Convert character to virtual key code + shift state
        SHORT keyInfo = VkKeyScanA(c);
        WORD keyCode = LOBYTE(keyInfo);
        bool needsShift = (HIBYTE(keyInfo) & 1) != 0;

        // Press Shift if needed (for uppercase/symbols like !@#)
        if (needsShift) {
            INPUT shiftInput = {0};
            shiftInput.type = INPUT_KEYBOARD;
            shiftInput.ki.wVk = VK_SHIFT;
            SendInput(1, &shiftInput, sizeof(INPUT));
        }

        // Press and release the character key
        PressKey(keyCode);

        // Release Shift if we pressed it
        if (needsShift) {
            INPUT shiftInput = {0};
            shiftInput.type = INPUT_KEYBOARD;
            shiftInput.ki.wVk = VK_SHIFT;
            shiftInput.ki.dwFlags = KEYEVENTF_KEYUP;
            SendInput(1, &shiftInput, sizeof(INPUT));
        }
    }
}

Step 2: Main Logic for Your Automation #

Now, the main function will handle the sequence you want: username → TAB → password → ENTER. We'll add a short delay to let your family member switch to the target program first.

int main() {
    // Wait 3 seconds so the user can switch to the program they want to input into
    Sleep(3000);

    // Type the username
    TypeString("username");
    // Press Tab to move to password field
    PressKey(VK_TAB);
    // Type the password
    TypeString("password");
    // Press Enter to submit
    PressKey(VK_RETURN);

    return 0;
}

Important Notes for Compilation & Usage #

• Link the required library: When compiling with MSVC, you need to link user32.lib (where SendInput lives). You can either add #pragma comment(lib, "user32.lib") at the top of your code, or add /link user32.lib to your compile command.
• Run with correct permissions: If the target program is running as administrator, your automation program also needs to run as admin—otherwise it might not be able to send input to the window.
• Testing tip: Start small! Test just typing a single character first, then add the Tab and Enter steps once that works. This helps you debug if something goes wrong.
• Alternative for stubborn programs: Some apps (like security tools or games) block SendInput. If that happens, you can try sending WM_CHAR messages directly to the input field's window handle, but that requires finding the specific input box (using FindWindowEx), which is a bit more advanced. Let me know if you need help with that!

Hope this gets you up and running smoothly. Take it slow, and don't hesitate to tweak the delay or adjust the functions to fit your family member's exact needs.

内容的提问来源于stack exchange，提问作者gabelepoudre