我想要关闭渲染但不退出程序

如果你想要关闭渲染但不退出程序，可以修改示例代码来实现。以下是修改后的示例代码：

#include <Windows.h>
#include <d3d11.h>

LRESULT CALLBACK WindowProc(HWND hWnd, UINT message, WPARAM wParam, LPARAM lParam);

HWND g_hWnd;
ID3D11Device* g_pDevice = nullptr;
ID3D11DeviceContext* g_pDeviceContext = nullptr;
IDXGISwapChain* g_pSwapChain = nullptr;
bool g_isRendering = true;

int WINAPI WinMain(HINSTANCE hInstance, HINSTANCE hPrevInstance, LPSTR lpCmdLine, int nCmdShow)
{
    // 创建窗口
    WNDCLASSEX wc = { sizeof(WNDCLASSEX), CS_CLASSDC, WindowProc, 0L, 0L, GetModuleHandle(NULL), NULL, NULL, NULL, NULL, _T("DX11App"), NULL };
    RegisterClassEx(&wc);
    g_hWnd = CreateWindow(wc.lpszClassName, _T("DX11 Application"), WS_OVERLAPPEDWINDOW, 100, 100, 800, 600, NULL, NULL, wc.hInstance, NULL);

    // 初始化 DirectX 设备和交换链
    DXGI_SWAP_CHAIN_DESC swapChainDesc = { 0 };
    swapChainDesc.BufferCount = 1;
    swapChainDesc.BufferDesc.Width = 800;
    swapChainDesc.BufferDesc.Height = 600;
    swapChainDesc.BufferDesc.Format = DXGI_FORMAT_R8G8B8A8_UNORM;
    swapChainDesc.BufferUsage = DXGI_USAGE_RENDER_TARGET_OUTPUT;
    swapChainDesc.OutputWindow = g_hWnd;
    swapChainDesc.SampleDesc.Count = 1;
    swapChainDesc.Windowed = TRUE;

    D3D11CreateDeviceAndSwapChain(NULL, D3D_DRIVER_TYPE_HARDWARE, NULL, 0, NULL, 0, D3D11_SDK_VERSION, &swapChainDesc, &g_pSwapChain, &g_pDevice, NULL, &g_pDeviceContext);

    // 创建渲染目标视图
    ID3D11RenderTargetView* pRenderTargetView = nullptr;
    ID3D11Texture2D* pBackBuffer = nullptr;
    g_pSwapChain->GetBuffer(0, __uuidof(ID3D11Texture2D), (LPVOID*)&pBackBuffer);
    g_pDevice->CreateRenderTargetView(pBackBuffer, NULL, &pRenderTargetView);
    pBackBuffer->Release();

    // 渲染循环
    MSG msg;
    while (g_isRendering)
    {
        if (PeekMessage(&msg, NULL, 0U, 0U, PM_REMOVE))
        {
            TranslateMessage(&msg);
            DispatchMessage(&msg);
        }
        else
        {
            // 清空渲染目标视图
            float clearColor[4] = { 0.0f, 0.0f, 0.0f, 0.0f }; // RGBA颜色，这里设置为透明色
            g_pDeviceContext->ClearRenderTargetView(pRenderTargetView, clearColor);

            // 在这里添加你的渲染代码

            // 呈现到屏幕
            g_pSwapChain->Present(0, 0);
        }
    }

    // 释放资源
    pRenderTargetView->Release();
    g_pDeviceContext->Release();
    g_pSwapChain->Release();
    g_pDevice->Release();

    // 销毁窗口
    DestroyWindow(g_hWnd);
    UnregisterClass(wc.lpszClassName, wc.hInstance);

    return 0;
}

LRESULT CALLBACK WindowProc(HWND hWnd, UINT message, WPARAM wParam, LPARAM lParam)
{
    switch (message)
    {
    case WM_CLOSE:
        g_isRendering = false; // 关闭渲染循环
        return 0;
    case WM_DESTROY:
        PostQuitMessage(0);
        return 0;
    }

    return DefWindowProc(hWnd, message, wParam, lParam);
}

在这个示例代码中，我们增加了一个全局变量 `g_isRendering` 来控制渲染循环是否继续进行。当收到 `WM_CLOSE` 消息时，我们将 `g_isRendering` 设置为 `false`，从而关闭渲染循环，但程序仍然保持运行。

这样，你可以在其他地方通过调用 `PostMessage(g_hWnd, WM_CLOSE, 0, 0)` 来关闭渲染循环，而不会退出程序。