Are you looking to create your own window using the CreateWindow function in C++? Look no further! In this step-by-step guide, we’ll take you through the process of creating a window from scratch using CreateWindow.

Before we get started, you’ll need a basic understanding of C++ programming and the Win32 API. If you’re new to either of these, we suggest taking a few online tutorials or classes to get up to speed.

Now, let’s begin.

Step 1: Create a Project

First, create a new project in your IDE of choice. In this example, we’ll be using Visual Studio 2019. Select “Win32 Console Application” and give your project a name. Be sure to select the “Empty Project” option, as we’ll be adding our own code.

Step 2: Include Windows.h

Next, we need to include the Windows.h header file, which contains the declarations for all of the Windows API functions we’ll be using. Add the following line at the top of your main.cpp file:

#include

Step 3: Declare Global Variables

Before we start creating our window, we need to declare some global variables that will be used throughout the program.

First, we’ll need a handle to our main window. Add the following line below the #include statement:

HWND hwnd;

Next, we’ll define our window class. The window class is a data structure that specifies the attributes of our window, such as its style, background color, and title. Add the following code below the hwnd declaration:

const char* CLASS_NAME = "MyWindowClass";

LRESULT CALLBACK WindowProc(HWND hwnd, UINT uMsg, WPARAM wParam, LPARAM lParam);

Step 4: Register the Window Class

Now, we’ll register our window class using the RegisterClassEx function. This tells Windows about the class of window we want to create. Add the following code to your main function:

WNDCLASSEX wc = {};

wc.cbSize = sizeof(WNDCLASSEX);

wc.style = CS_HREDRAW | CS_VREDRAW;

wc.lpfnWndProc = WindowProc;

wc.hInstance = hInstance;

wc.hCursor = LoadCursor(NULL, IDC_ARROW);

wc.hbrBackground = (HBRUSH)(COLOR_WINDOW + 1);

wc.lpszClassName = CLASS_NAME;

RegisterClassEx(&wc);

Here, we create a new WNDCLASSEX structure, set its size, style, and other attributes, and register it using the RegisterClassEx function.

Step 5: Create the Window

Now, we’re ready to create our window using the CreateWindow function. Add the following code to your main function:

hwnd = CreateWindow(CLASS_NAME, "My Window", WS_OVERLAPPEDWINDOW,

CW_USEDEFAULT, CW_USEDEFAULT, 800, 600, NULL, NULL, hInstance, NULL);

Here, we specify the class name, window title, style, and size of our window. The last argument, hInstance, is a handle to the current instance of the application.

Step 6: Show and Update the Window

Finally, we need to show and update our new window. Add the following code at the end of your main function:

ShowWindow(hwnd, nCmdShow);

UpdateWindow(hwnd);

The ShowWindow function shows the window on the screen, while UpdateWindow processes any messages that are waiting in the message queue.

Step 7: Handle Window Messages

Now, we need to handle any messages that are sent to our window, such as mouse clicks or keyboard input. Add the following code outside of your main function:

LRESULT CALLBACK WindowProc(HWND hwnd, UINT uMsg, WPARAM wParam, LPARAM lParam)

{

switch (uMsg)

{

case WM_DESTROY:

PostQuitMessage(0);

break;

default:

return DefWindowProc(hwnd, uMsg, wParam, lParam);

}

return 0;

}

Here, we define a new function that takes care of our window messages. Currently, it only handles the WM_DESTROY message, which is sent when the user closes the window.

Step 8: Build and Run Your Program

Finally, we’re ready to build and run our program. Press F5 in Visual Studio to build and run the program. You should see a new window appear on the screen with the title “My Window”.

Congratulations! You’ve successfully created a window from scratch using the CreateWindow function. With this knowledge, you’ll be able to create all sorts of custom windows for your applications.