Win32 CreateWindow GdiPlus

#include "stdafx.h"
#include "TestGidPlus.h"

LRESULT CALLBACK WndProc(HWND, UINT, WPARAM, LPARAM);

int APIENTRY _tWinMain(HINSTANCE hInstance, HINSTANCE hPrevInstance, LPTSTR lpCmdLine, int nCmdShow)
{
	GdiplusStartupInput gdiplusStartupInput;
	ULONG_PTR           gdiplusToken;
	// Initialize GDI+.
	GdiplusStartup(&gdiplusToken, &gdiplusStartupInput, NULL);

	WNDCLASSEX wcApp;
	wcApp.lpszClassName			= TEXT("Test_Window");
	wcApp.cbSize				= sizeof(wcApp);
	wcApp.style					= CS_HREDRAW | CS_VREDRAW;
	wcApp.hInstance				= hInstance;
	wcApp.cbWndExtra			= 0;	
	wcApp.cbClsExtra			= 0;
	wcApp.hCursor				= LoadCursor(NULL,IDC_ARROW);
	wcApp.hIcon					= LoadIcon(NULL,IDI_APPLICATION);
	wcApp.lpfnWndProc			= WndProc;
	wcApp.hCursor				= LoadCursor(NULL,IDC_ARROW);
	wcApp.hbrBackground			= (HBRUSH)(COLOR_WINDOW);
	wcApp.lpszMenuName			= NULL;
	wcApp.hIconSm				= NULL;
	RegisterClassExW(&wcApp);

	HWND hwnd = CreateWindowExW (NULL, TEXT("Test_Window"), TEXT(""), WS_OVERLAPPEDWINDOW, 100, 100, 600, 400, NULL, NULL, hInstance, NULL);
	ShowWindow(hwnd,SW_NORMAL);
	UpdateWindow(hwnd);
	MSG msg;
	while (GetMessage(&msg, NULL, 0, 0)) 
	{
		TranslateMessage(&msg);
		DispatchMessage(&msg);
	}
	GdiplusShutdown(gdiplusToken);
	return msg.lParam;
}

LRESULT CALLBACK WndProc (HWND hwnd, UINT message, WPARAM wParam, LPARAM lParam)
{
	LRESULT b;
	PAINTSTRUCT ps;
	HDC hdc;
	switch (message)
	{
	case WM_CREATE:
		//SendMessage(hwnd,WM_PAINT,0,0);
		break;
	case WM_PAINT:
		{
			///////////////////Gdiplus与Gdi混合实现双缓冲////////////////////
			//HDC hMemDC = CreateCompatibleDC(m_hDC);
			//HBITMAP hMemBitmap = CreateCompatibleBitmap(m_hDC, DEFAULT_STATUS_WIDTH, DEFAULT_STATUS_HEIGHT);
			//SelectObject(hMemDC, hMemBitmap);
			//Graphics *memGraphics = new Graphics(hMemDC);
			//Pen pen(Color(192, 192, 192));
			//SolidBrush brush(Color(255, 255, 255));
			//memGraphics->FillRectangle(&brush, xPos, yPos, DEFAULT_STATUS_WIDTH, DEFAULT_STATUS_HEIGHT);
			//memGraphics->DrawRectangle(&pen, xPos, yPos, DEFAULT_STATUS_WIDTH, DEFAULT_STATUS_HEIGHT);
			//for (int i = 0; i