Come creare un semplice albero visivo
Nota
Per le app in Windows 10, è consigliabile usare le API Windows.UI.Composition anziché DirectComposition. Per altre informazioni, vedere Modernizzare l'app desktop usando il livello visuale.
Questo argomento illustra come creare un semplice albero visivo microsoft DirectComposition. L'esempio in questo argomento compila e compone un albero visivo costituito da un oggetto visivo radice e da tre oggetti visivi figlio. Il contenuto dell'oggetto visivo radice è una bitmap blu chiaro che funge da sfondo per gli oggetti visivi figlio. Questa figura mostra la composizione creata dal codice di esempio in questo argomento.
Informazioni importanti
Tecnologie
Prerequisiti
Conoscenza di:
- C/C++
- Microsoft Win32
- Component Object Model (COM)
Istruzioni
Passaggio 1: Inizializzare gli oggetti di destinazione del dispositivo e della composizione
Per altre informazioni, vedere Come inizializzare DirectComposition.
Passaggio 2: Creare gli oggetti visivi e impostare il contenuto bitmap
Utilizzare il metodo IDCompositionDevice::CreateVisual per creare gli oggetti visivi e il metodo IDCompositionVisual::SetContent per impostare il contenuto bitmap degli oggetti visivi.
Nota
Nell'esempio seguente il primo elemento della m_hBitmaps matrice contiene la bitmap per l'oggetto visivo radice e gli elementi rimanenti contengono le bitmap per gli oggetti visivi figlio.
#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;
}
}
La funzione definita dall'applicazione seguente illustra come creare la superficie Microsoft DirectComposition e eseguire il rendering di una bitmap GDI (Windows Graphics Device Interface) nella superficie.
// 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;
}
Passaggio 3: Impostare l'oggetto visivo radice
Impostare gli offset orizzontali e verticali dell'oggetto visivo radice e quindi aggiungerlo all'albero visivo chiamando il metodo IDCompositionTarget::SetRoot .
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]);
Passaggio 4: Aggiungere gli oggetti visivi figlio e eseguire il commit della composizione
Usare i metodi esposti dall'interfaccia IDCompositionVisual di ogni oggetto visivo figlio per impostare il contenuto bitmap e altre proprietà e quindi usare il metodo IDCompositionVisual::AddVisual dell'oggetto visivo radice per aggiungere gli oggetti visivi figlio alla radice dell'albero visivo. Chiamare IDCompositionDevice::Commit per eseguire il commit del batch di comandi in DirectComposition per l'elaborazione. La composizione risultante viene visualizzata nella finestra di destinazione.
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();
Passaggio 5: Liberare gli oggetti DirectComposition
Liberare gli oggetti visivi non appena non sono più necessari. Questo bit di codice successivo chiama la macro SafeRelease definita dall'applicazione per liberare gli oggetti visivi.
Cleanup:
// Free the visuals.
for (int i = 0; i < NUM_VISUALS; i++)
{
SafeRelease(&pVisuals[i]);
}
Inoltre, ricordarsi di liberare gli oggetti di destinazione del dispositivo e della composizione prima dell'uscita dall'applicazione.
SafeRelease(&m_pD3D11Device);
SafeRelease(&m_pDevice);
SafeRelease(&m_pCompTarget);
Esempio completo
// 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.
// Refer to MSDN for the latest info on corresponding values for different platforms.
#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;
}
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