下载源码：imgui github地址

将需要的文件拖拽入项目外部库的imgui文件夹

backends文件夹里选择与环境适配的文件，我这里用了glfw和opengl3

目录结构：

CMakeLists.txt

cmake_minimum_required(VERSION 3.24)
project(proforlearn)
set(CMAKE_CXX_STANDARD 17)


file(GLOB SRC
        ${PROJECT_SOURCE_DIR}/external/imgui/*.h
        ${PROJECT_SOURCE_DIR}/external/imgui/*.cpp
)
add_executable(proforlearn ${SRC} main.cpp)

find_package(OpenGL REQUIRED)
include_directories(${PROJECT_SOURCE_DIR}/external/glfw/include)
link_directories(${PROJECT_SOURCE_DIR}/external/glfw/lib-mingw-w64)
target_link_libraries(proforlearn opengl32 glfw3.dll)

include_directories(${PROJECT_SOURCE_DIR}/external/imgui)

测试代码：

#include "imgui.h"
#include "imgui_impl_glfw.h"
#include "imgui_impl_opengl3.h"

#include <GLFW/glfw3.h>

int main(void)
{
    GLFWwindow* window;

    /* Initialize the library */
    if (!glfwInit())
        return -1;

    /* Create a windowed mode window and its OpenGL context */
    window = glfwCreateWindow(640, 480, "Hello World", NULL, NULL);
    if (!window)
    {
        glfwTerminate();
        return -1;
    }

    /* Make the window's context current */
    glfwMakeContextCurrent(window);

    IMGUI_CHECKVERSION();
    ImGui::CreateContext();
    ImGuiIO& io = ImGui::GetIO(); (void)io;
    ImGui_ImplGlfw_InitForOpenGL(window, true);
    ImGui_ImplOpenGL3_Init("#version 330");

    /* Loop until the user closes the window */
    while (!glfwWindowShouldClose(window))
    {
        /* Render here */
        glClear(GL_COLOR_BUFFER_BIT);

        ImGui_ImplOpenGL3_NewFrame();
        ImGui_ImplGlfw_NewFrame();
        ImGui::NewFrame();

        ImGui::Begin("My name is window, ImGUI window");
        ImGui::Text("Hello there new born!");
        ImGui::End();
        ImGui::Render();
        ImGui_ImplOpenGL3_RenderDrawData(ImGui::GetDrawData());


        /* Swap front and back buffers */
        glfwSwapBuffers(window);

        /* Poll for and process events */
        glfwPollEvents();
    }

    ImGui_ImplOpenGL3_Shutdown();
    ImGui_ImplGlfw_Shutdown();
    ImGui::DestroyContext();

    glfwTerminate();
    return 0;
}

运行结果：glfw黑框中成功出现imgui文本界面！