显示“打印”对话框

获取打印机的设备上下文句柄的一种方法是显示打印对话框，并允许用户选择打印机。 PrintDlg 函数 (显示对话框) 具有一个参数，即 PRINTDLG 结构的地址。 PRINTDLG 结构具有多个成员，但你可以将其中的大多数设置为默认值。 需要设置的两个成员是 lStructSize 和 Flags。 将 lStructSize 设置为 PRINTDLG 变量的大小，并将 Flags 设置为 PD_RETURNDC。 将 Flags 设置为 PC_RETURNDC 指定希望 PrintDlg 函数使用用户选择的打印机的设备上下文句柄填充 hDC 字段。

#include <windows.h>
#include <gdiplus.h>
#include <stdio.h>
using namespace Gdiplus;

INT main()
{
   // Initialize GDI+.
   GdiplusStartupInput gdiplusStartupInput;
   ULONG_PTR gdiplusToken;
   GdiplusStartup(&gdiplusToken, &gdiplusStartupInput, NULL);
   
   DOCINFO docInfo;
   ZeroMemory(&docInfo, sizeof(docInfo));
   docInfo.cbSize = sizeof(docInfo);
   docInfo.lpszDocName = "GdiplusPrint";
   
   // Create a PRINTDLG structure, and initialize the appropriate fields.
   PRINTDLG printDlg;
   ZeroMemory(&printDlg, sizeof(printDlg));
   printDlg.lStructSize = sizeof(printDlg);
   printDlg.Flags = PD_RETURNDC;
   
   // Display a print dialog box.
   if(!PrintDlg(&printDlg))
   {
      printf("Failure\n");
   }
   else
   {
      // Now that PrintDlg has returned, a device context handle
      // for the chosen printer is in printDlg->hDC.
      
      StartDoc(printDlg.hDC, &docInfo);
      StartPage(printDlg.hDC);
         Graphics* graphics = new Graphics(printDlg.hDC);
         Pen* pen = new Pen(Color(255, 0, 0, 0));
         graphics->DrawRectangle(pen, 200, 500, 200, 150);
         graphics->DrawEllipse(pen, 200, 500, 200, 150);
         graphics->DrawLine(pen, 200, 500, 400, 650);
         delete pen;
         delete graphics;
      EndPage(printDlg.hDC);
      EndDoc(printDlg.hDC); 
   }
   if(printDlg.hDevMode) 
      GlobalFree(printDlg.hDevMode);
   if(printDlg.hDevNames) 
      GlobalFree(printDlg.hDevNames);
   if(printDlg.hDC)
      DeleteDC(printDlg.hDC);
   
   GdiplusShutdown(gdiplusToken);
   return 0;
}