如何生成简单的可视化树
注意
对于 Windows 10 上的应用，建议使用 Windows.UI.Composition API 而不是 DirectComposition。 有关详细信息，请参阅 使用视觉对象层实现桌面应用的现代化。
本主题演示如何生成简单的 Microsoft DirectComposition 可视化树。 本主题中的示例生成并编写一个由根视觉对象和三个子视觉对象组成的可视化树。 根视觉对象的内容是浅蓝色位图，用作子视觉对象的背景。 此图显示了本主题中的示例代码创建的合成。
需要了解的事项
技术
先决条件
了解：
- C/C++
- Microsoft Win32
- 组件对象模型 (COM)
Instructions
步骤 1：初始化设备和组合目标对象
有关详细信息，请参阅 如何初始化 DirectComposition。
步骤 2：创建视觉对象并设置位图内容
使用 IDCompositionDevice：：CreateVisual 方法创建视觉对象，使用 IDCompositionVisual：：SetContent 方法设置视觉对象的位图内容。
注意
在以下示例中，数组的第一个 m_hBitmaps 元素包含根视觉对象的位图，其余元素包含子视觉对象的位图。
#define NUM_VISUALS 4 // number of visuals in the composition
HBITMAP m_hBitmaps[NUM_VISUALS];
HRESULT hr = S_OK;
IDCompositionVisual *pVisuals[NUM_VISUALS]{ };
IDCompositionSurface *pSurface{ nullptr };
// Create a visual objects and set their content.
for (int i = 0; i < NUM_VISUALS; i++)
{
hr = m_pDevice->CreateVisual(&pVisuals[i]);
if (SUCCEEDED(hr))
{
// This application-defined function creates a DirectComposition
// surface and renders a GDI bitmap onto the surface.
hr = MyCreateGDIRenderedDCompSurface(m_hBitmaps[i], &pSurface);
if (SUCCEEDED(hr))
{
// Set the bitmap content.
hr = pVisuals[i]->SetContent(pSurface);
}
SafeRelease(&pSurface);
}
if (FAILED(hr))
{
goto Cleanup;
}
}
以下应用程序定义的函数演示如何创建 Microsoft DirectComposition 图面，以及如何将 Windows 图形设备接口 (GDI) 位图呈现到图面。
// MyCreateGDIRenderedDCompSurface - Creates a DirectComposition surface and
// copies the bitmap to the surface.
//
// Parameters:
// hBitmap - a GDI bitmap.
// ppSurface - the composition surface object.
//
HRESULT DemoApp::MyCreateGDIRenderedDCompSurface(HBITMAP hBitmap, IDCompositionSurface **ppSurface)
{
HRESULT hr = S_OK;
int bitmapWidth = 0;
int bitmapHeight = 0;
int bmpSize = 0;
BITMAP bmp = { };
HBITMAP hBitmapOld = NULL;
HDC hSurfaceDC = NULL;
HDC hBitmapDC = NULL;
IDXGISurface1 *pDXGISurface = nullptr;
POINT pointOffset = { };
hr = hBitmap ? S_OK : E_FAIL;
if (SUCCEEDED(hr))
{
// Get information about the bitmap.
bmpSize = GetObject(hBitmap, sizeof(BITMAP), &bmp);
}
hr = bmpSize ? S_OK : E_FAIL;
if (SUCCEEDED(hr))
{
// Save the bitmap dimensions.
bitmapWidth = bmp.bmWidth;
bitmapHeight = bmp.bmHeight;
// Create a DirectComposition-compatible surface that is the same size
// as the bitmap.
hr = m_pDevice->CreateSurface(bitmapWidth, bitmapHeight,
DXGI_FORMAT_B8G8R8A8_UNORM, DXGI_ALPHA_MODE_IGNORE, ppSurface);
}
hr = ppSurface ? S_OK : E_FAIL;
if (SUCCEEDED(hr))
{
hr = (*ppSurface)->BeginDraw(NULL, __uuidof(IDXGISurface1),
reinterpret_cast<void**>(&pDXGISurface), &pointOffset);
}
if (SUCCEEDED(hr))
{
pDXGISurface->GetDC(FALSE, &hSurfaceDC);
}
hr = hSurfaceDC ? S_OK : E_FAIL;
if (SUCCEEDED(hr))
{
hBitmapDC = CreateCompatibleDC(hSurfaceDC);
if (hBitmapDC != NULL)
{
hBitmapOld = (HBITMAP)SelectObject(hBitmapDC, hBitmap);
BitBlt(hSurfaceDC, pointOffset.x, pointOffset.y,
bitmapWidth, bitmapHeight, hBitmapDC, 0, 0, SRCCOPY);
if (hBitmapOld)
{
SelectObject(hBitmapDC, hBitmapOld);
}
DeleteDC(hBitmapDC);
}
pDXGISurface->ReleaseDC(NULL);
}
(*ppSurface)->EndDraw();
SafeRelease(&pDXGISurface);
return hr;
}
步骤 3：设置根视觉对象
设置根视觉对象的水平和垂直偏移量，然后通过调用 IDCompositionTarget：：SetRoot 方法将其添加到可视化树。
float xPosRoot = 50.0;
float yPosRoot = 50.0;
// Set the horizontal and vertical position of the root visual.
pVisuals[0]->SetOffsetX(xPosRoot);
pVisuals[0]->SetOffsetY(yPosRoot);
// Set the root visual of the visual tree.
hr = m_pCompTarget->SetRoot(pVisuals[0]);
步骤 4：添加子视觉对象，并提交合成
使用由每个子视觉对象的 IDCompositionVisual 接口公开的方法设置位图内容和其他属性，然后使用根视觉对象的 IDCompositionVisual：：AddVisual 方法将子视觉对象添加到可视化树的根目录。 调用 IDCompositionDevice：：Commit 将命令批提交到 DirectComposition 进行处理。 生成的组合将显示在目标窗口中。
float xPosChild = 20.0f;
float yPosChild = 20.0f;
if (SUCCEEDED(hr))
{
// Set the positions of the child visuals and add them to the visual tree.
for (int i = 1; i < NUM_VISUALS; i++)
{
pVisuals[i]->SetOffsetX(xPosChild);
pVisuals[i]->SetOffsetY(
static_cast<float>((yPosChild * i) + (CHILD_BITMAP_HEIGHT * (i - 1))));
// Add the child visuals as children of the root visual.
pVisuals[0]->AddVisual(pVisuals[i], TRUE, nullptr);
}
}
// Commit the visual to be composed and displayed.
hr = m_pDevice->Commit();
步骤 5：释放 DirectComposition 对象
在不再需要视觉对象时立即释放它们。 下一位代码调用应用程序定义的 SafeRelease 宏来释放视觉对象。
Cleanup:
// Free the visuals.
for (int i = 0; i < NUM_VISUALS; i++)
{
SafeRelease(&pVisuals[i]);
}
此外，请记住在应用程序退出之前释放设备和组合目标对象。
SafeRelease(&m_pD3D11Device);
SafeRelease(&m_pDevice);
SafeRelease(&m_pCompTarget);
完整示例
// THIS CODE AND INFORMATION IS PROVIDED "AS IS" WITHOUT WARRANTY OF
// ANY KIND, EITHER EXPRESSED OR IMPLIED, INCLUDING BUT NOT LIMITED TO
// THE IMPLIED WARRANTIES OF MERCHANTABILITY AND/OR FITNESS FOR A
// PARTICULAR PURPOSE.
//
// Copyright (c) Microsoft Corporation. All rights reserved
#pragma once
// Modify the following definitions if you need to target a platform prior to the ones specified below.
#ifndef WINVER // Allow use of features specific to Windows 7 or later.
#define WINVER 0x0700 // Change this to the appropriate value to target other versions of Windows.
#endif
#ifndef _WIN32_WINNT // Allow use of features specific to Windows 7 or later.
#define _WIN32_WINNT 0x0700 // Change this to the appropriate value to target other versions of Windows.
#endif
#ifndef UNICODE
#define UNICODE
#endif
#define WIN32_LEAN_AND_MEAN // Exclude rarely-used items from Windows headers
// Windows Header Files:
#include <windows.h>
// C RunTime Header Files
#include <math.h>
#include <dcomp.h>
#include <d3d11.h>
/******************************************************************
* *
* Macros *
* *
******************************************************************/
template<class Interface>
inline void
SafeRelease(
Interface **ppInterfaceToRelease
)
{
if (*ppInterfaceToRelease != NULL)
{
(*ppInterfaceToRelease)->Release();
(*ppInterfaceToRelease) = NULL;
}
}
#ifndef Assert
#if defined( DEBUG ) || defined( _DEBUG )
#define Assert(b) if (!(b)) {OutputDebugStringA("Assert: " #b "\n");}
#else
#define Assert(b)
#endif //DEBUG || _DEBUG
#endif
#ifndef HINST_THISCOMPONENT
EXTERN_C IMAGE_DOS_HEADER __ImageBase;
#define HINST_THISCOMPONENT ((HINSTANCE)&__ImageBase)
#endif
// Application-defined constants
#define NUM_VISUALS 4 // number of visuals in the composition
#define CHILD_BITMAP_HEIGHT 96 // height, in pixels, of a child visual
#define NUM_BITMAPS 4 // number of bitmaps in the composition
/******************************************************************
* *
* DemoApp *
* *
******************************************************************/
class DemoApp
{
public:
DemoApp();
~DemoApp();
HRESULT Initialize();
void RunMessageLoop();
private:
HRESULT InitializeDirectCompositionDevice();
HRESULT CreateResources();
void DiscardResources();
HRESULT OnClientClick();
HRESULT DemoApp::LoadResourceGDIBitmap(
PCWSTR resourceName,
HBITMAP &hbmp
);
HRESULT DemoApp::MyCreateGDIRenderedDCompSurface(HBITMAP hBitmap, IDCompositionSurface **ppSurface);
static LRESULT CALLBACK WndProc(
HWND hWnd,
UINT message,
WPARAM wParam,
LPARAM lParam
);
private:
HWND m_hwnd;
HBITMAP m_hBitmaps[NUM_VISUALS];
ID3D11Device *m_pD3D11Device;
IDCompositionDevice *m_pDevice;
IDCompositionTarget *m_pCompTarget;
};
// THIS CODE AND INFORMATION IS PROVIDED "AS IS" WITHOUT WARRANTY OF
// ANY KIND, EITHER EXPRESSED OR IMPLIED, INCLUDING BUT NOT LIMITED TO
// THE IMPLIED WARRANTIES OF MERCHANTABILITY AND/OR FITNESS FOR A
// PARTICULAR PURPOSE.
//
// Copyright (c) Microsoft Corporation. All rights reserved
// Instructions: Right-click in the client area to cause DirectCompostion
// to create a simple composition consisting a root visual and three child
// visuals. The root visual provides the background bitmap for the
// composition, and the three child visuals provide bitmaps that are
// composed on top of the root. All bitmaps are GDI.
#include "SimpleVisualTree.h"
/******************************************************************
* *
* The application entry point. *
* *
******************************************************************/
int WINAPI WinMain(
HINSTANCE /* hInstance */,
HINSTANCE /* hPrevInstance */,
LPSTR /* lpCmdLine */,
int /* nCmdShow */
)
{
// Ignore the return value because we want to run the program even in the
// unlikely event that HeapSetInformation fails.
HeapSetInformation(NULL, HeapEnableTerminationOnCorruption, NULL, 0);
if (SUCCEEDED(CoInitialize(NULL)))
{
{
DemoApp app;
if (SUCCEEDED(app.Initialize()))
{
app.RunMessageLoop();
}
}
CoUninitialize();
}
return 0;
}
/******************************************************************
* *
* DemoApp::DemoApp constructor *
* *
* Initialize member data. *
* *
******************************************************************/
DemoApp::DemoApp() :
m_hwnd(NULL),
m_hBitmaps(),
m_pD3D11Device(nullptr),
m_pDevice(nullptr),
m_pCompTarget(nullptr)
{
}
/******************************************************************
* *
* Release resources. *
* *
******************************************************************/
DemoApp::~DemoApp()
{
SafeRelease(&m_pD3D11Device);
SafeRelease(&m_pDevice);
SafeRelease(&m_pCompTarget);
}
/*******************************************************************
* *
* Create the application window. *
* *
*******************************************************************/
HRESULT DemoApp::Initialize()
{
HRESULT hr;
// Register the window class.
WNDCLASSEX wcex = { sizeof(WNDCLASSEX) };
wcex.style = CS_HREDRAW | CS_VREDRAW;
wcex.lpfnWndProc = DemoApp::WndProc;
wcex.cbClsExtra = 0;
wcex.cbWndExtra = sizeof(LONG_PTR);
wcex.hInstance = HINST_THISCOMPONENT;
wcex.hbrBackground = (HBRUSH)(COLOR_WINDOW+1);;
wcex.lpszMenuName = NULL;
wcex.hCursor = LoadCursor(NULL, IDC_ARROW);
wcex.lpszClassName = L"DirectCompDemoApp";
RegisterClassEx(&wcex);
// Create the application window.
//
// Because the CreateWindow function takes its size in pixels, we
// obtain the system DPI and use it to scale the window size.
int dpiX = 0;
int dpiY = 0;
HDC hdc = GetDC(NULL);
if (hdc)
{
dpiX = GetDeviceCaps(hdc, LOGPIXELSX);
dpiY = GetDeviceCaps(hdc, LOGPIXELSY);
ReleaseDC(NULL, hdc);
}
m_hwnd = CreateWindow(
L"DirectCompDemoApp",
L"DirectComposition Demo Application",
WS_OVERLAPPEDWINDOW,
CW_USEDEFAULT,
CW_USEDEFAULT,
static_cast<UINT>(ceil(640.f * dpiX / 96.f)),
static_cast<UINT>(ceil(480.f * dpiY / 96.f)),
NULL,
NULL,
HINST_THISCOMPONENT,
this
);
hr = m_hwnd ? S_OK : E_FAIL;
if (SUCCEEDED(hr))
{
ShowWindow(m_hwnd, SW_SHOWNORMAL);
UpdateWindow(m_hwnd);
// Initialize DirectComposition resources, such as the
// device object and composition target object.
hr = InitializeDirectCompositionDevice();
}
if (SUCCEEDED(hr))
{
hr = CreateResources();
}
return hr;
}
/******************************************************************
* *
* This method creates the DirectComposition device object and *
* and the composition target object. These objects endure for *
* the lifetime of the application. *
* *
******************************************************************/
HRESULT DemoApp::InitializeDirectCompositionDevice()
{
HRESULT hr = S_OK;
D3D_FEATURE_LEVEL featureLevelSupported;
IDXGIDevice *pDXGIDevice = nullptr;
// Create the D3D device object.
D3D11CreateDevice(
nullptr,
D3D_DRIVER_TYPE_HARDWARE,
NULL,
D3D11_CREATE_DEVICE_BGRA_SUPPORT,
NULL,
0,
D3D11_SDK_VERSION,
&m_pD3D11Device,
&featureLevelSupported,
NULL);
hr = (m_pD3D11Device == nullptr) ? E_UNEXPECTED : S_OK;
if (SUCCEEDED(hr))
{
// Create the DXGI device used to create bitmap surfaces.
hr = m_pD3D11Device->QueryInterface(&pDXGIDevice);
}
if (SUCCEEDED(hr))
{
// Create the DirectComposition device object.
hr = DCompositionCreateDevice(pDXGIDevice, __uuidof(IDCompositionDevice),
reinterpret_cast<void **>(&m_pDevice));
}
if (SUCCEEDED(hr))
{
// Create the composition target object.
hr = m_pDevice->CreateTargetForHwnd(m_hwnd, TRUE, &m_pCompTarget);
}
SafeRelease(&pDXGIDevice);
return hr;
}
/******************************************************************
* *
* This method creates the GDI bitmaps to be associated with *
* DirectComposition visual objects. *
* *
******************************************************************/
HRESULT DemoApp::CreateResources()
{
HRESULT hr = S_OK;
hr = LoadResourceGDIBitmap(L"Background", m_hBitmaps[0]);
hr = LoadResourceGDIBitmap(L"BlkKnight", m_hBitmaps[1]);
hr = LoadResourceGDIBitmap(L"BlkQueen", m_hBitmaps[2]);
hr = LoadResourceGDIBitmap(L"BlkRook", m_hBitmaps[3]);
return hr;
}
/******************************************************************
* *
* Discard device-specific resources. *
* *
******************************************************************/
void DemoApp::DiscardResources()
{
int i = 0;
while (i < NUM_VISUALS)
{
DeleteObject(m_hBitmaps[i++]);
}
}
/******************************************************************
* *
* The main window's message loop. *
* *
******************************************************************/
void DemoApp::RunMessageLoop()
{
MSG msg;
while (GetMessage(&msg, NULL, 0, 0))
{
TranslateMessage(&msg);
DispatchMessage(&msg);
}
}
/******************************************************************
* *
* Called whenever the user clicks the client area of the main *
* window. This method builds a simple visual tree consisting of *
* a root visual and three child visuals. *
******************************************************************/
HRESULT DemoApp::OnClientClick()
{
HRESULT hr = S_OK;
IDCompositionVisual *pVisuals[NUM_VISUALS] = { };
IDCompositionSurface *pSurface = nullptr;
// Create a visual objects and set their content.
for (int i = 0; i < NUM_VISUALS; i++)
{
hr = m_pDevice->CreateVisual(&pVisuals[i]);
if (SUCCEEDED(hr))
{
// This application-defined function creates a DirectComposition
// surface and renders a GDI bitmap onto the surface.
hr = MyCreateGDIRenderedDCompSurface(m_hBitmaps[i], &pSurface);
if (SUCCEEDED(hr))
{
// Set the bitmap content.
hr = pVisuals[i]->SetContent(pSurface);
}
SafeRelease(&pSurface);
}
if (FAILED(hr))
{
goto Cleanup;
}
}
float xPosRoot = 50.0;
float yPosRoot = 50.0;
// Set the horizontal and vertical position of the root visual.
pVisuals[0]->SetOffsetX(xPosRoot);
pVisuals[0]->SetOffsetY(yPosRoot);
// Set the root visual of the visual tree.
hr = m_pCompTarget->SetRoot(pVisuals[0]);
float xPosChild = 20.0f;
float yPosChild = 20.0f;
if (SUCCEEDED(hr))
{
// Set the positions of the child visuals and add them to the visual tree.
for (int i = 1; i < NUM_VISUALS; i++)
{
pVisuals[i]->SetOffsetX(xPosChild);
pVisuals[i]->SetOffsetY(
static_cast<float>((yPosChild * i) + (CHILD_BITMAP_HEIGHT * (i - 1))));
// Add the child visuals as children of the root visual.
pVisuals[0]->AddVisual(pVisuals[i], TRUE, nullptr);
}
}
// Commit the visual to be composed and displayed.
hr = m_pDevice->Commit();
Cleanup:
// Free the visuals.
for (int i = 0; i < NUM_VISUALS; i++)
{
SafeRelease(&pVisuals[i]);
}
return hr;
}
/******************************************************************
* *
* The window's message handler. *
* *
******************************************************************/
LRESULT CALLBACK DemoApp::WndProc(HWND hwnd, UINT message, WPARAM wParam, LPARAM lParam)
{
LRESULT result = 0;
if (message == WM_CREATE)
{
LPCREATESTRUCT pcs = (LPCREATESTRUCT)lParam;
DemoApp *pDemoApp = (DemoApp *)pcs->lpCreateParams;
::SetWindowLongPtrW(
hwnd,
GWLP_USERDATA,
PtrToUlong(pDemoApp)
);
result = 1;
}
else
{
DemoApp *pDemoApp = reinterpret_cast<DemoApp *>(static_cast<LONG_PTR>(
::GetWindowLongPtrW(
hwnd,
GWLP_USERDATA
)));
bool wasHandled = false;
if (pDemoApp)
{
switch (message)
{
case WM_LBUTTONDOWN:
{
pDemoApp->OnClientClick();
}
case WM_DISPLAYCHANGE:
{
InvalidateRect(hwnd, NULL, FALSE);
}
wasHandled = true;
result = 0;
break;
case WM_DESTROY:
{
PostQuitMessage(0);
pDemoApp->DiscardResources();
}
wasHandled = true;
result = 1;
break;
}
}
if (!wasHandled)
{
result = DefWindowProc(hwnd, message, wParam, lParam);
}
}
return result;
}
/******************************************************************
* *
* This method loads the specified GDI bitmap from the *
* application resources, creates a new bitmap that is in a *
* format that DirectComposition can use, and copies the contents *
* of the original bitmap to the new bitmap. *
* *
******************************************************************/
HRESULT DemoApp::LoadResourceGDIBitmap(PCWSTR resourceName, HBITMAP &hbmp)
{
// Load the bitmap from the application resources.
hbmp = static_cast<HBITMAP>(LoadImageW(HINST_THISCOMPONENT, resourceName,
IMAGE_BITMAP, 0, 0, LR_DEFAULTCOLOR));
return hbmp ? S_OK : E_FAIL;
}
// MyCreateGDIRenderedDCompSurface - Creates a DirectComposition surface and
// copies the bitmap to the surface.
//
// Parameters:
// hBitmap - a GDI bitmap.
// ppSurface - the composition surface object.
//
HRESULT DemoApp::MyCreateGDIRenderedDCompSurface(HBITMAP hBitmap, IDCompositionSurface **ppSurface)
{
HRESULT hr = S_OK;
int bitmapWidth = 0;
int bitmapHeight = 0;
int bmpSize = 0;
BITMAP bmp = { };
HBITMAP hBitmapOld = NULL;
HDC hSurfaceDC = NULL;
HDC hBitmapDC = NULL;
IDXGISurface1 *pDXGISurface = nullptr;
POINT pointOffset = { };
hr = hBitmap ? S_OK : E_FAIL;
if (SUCCEEDED(hr))
{
// Get information about the bitmap.
bmpSize = GetObject(hBitmap, sizeof(BITMAP), &bmp);
}
hr = bmpSize ? S_OK : E_FAIL;
if (SUCCEEDED(hr))
{
// Save the bitmap dimensions.
bitmapWidth = bmp.bmWidth;
bitmapHeight = bmp.bmHeight;
// Create a DirectComposition-compatible surface that is the same size
// as the bitmap.
hr = m_pDevice->CreateSurface(bitmapWidth, bitmapHeight,
DXGI_FORMAT_B8G8R8A8_UNORM, DXGI_ALPHA_MODE_IGNORE, ppSurface);
}
hr = ppSurface ? S_OK : E_FAIL;
if (SUCCEEDED(hr))
{
hr = (*ppSurface)->BeginDraw(NULL, __uuidof(IDXGISurface1),
reinterpret_cast<void**>(&pDXGISurface), &pointOffset);
}
if (SUCCEEDED(hr))
{
pDXGISurface->GetDC(FALSE, &hSurfaceDC);
}
hr = hSurfaceDC ? S_OK : E_FAIL;
if (SUCCEEDED(hr))
{
hBitmapDC = CreateCompatibleDC(hSurfaceDC);
if (hBitmapDC != NULL)
{
hBitmapOld = (HBITMAP)SelectObject(hBitmapDC, hBitmap);
BitBlt(hSurfaceDC, pointOffset.x, pointOffset.y,
bitmapWidth, bitmapHeight, hBitmapDC, 0, 0, SRCCOPY);
if (hBitmapOld)
{
SelectObject(hBitmapDC, hBitmapOld);
}
DeleteDC(hBitmapDC);
}
pDXGISurface->ReleaseDC(NULL);
}
(*ppSurface)->EndDraw();
SafeRelease(&pDXGISurface);
return hr;
}