最近Leadtools發布了關于如何將PDF轉換為JPEG和將多頁TIFF轉換為PDF。最近有客戶問到如何將多個圖像添加到PDF中。幸運的是，LEADTOOLS支持150多種光柵、矢量和文檔文件格式，包括SVG、JPEG、PNG等。因此，讓我們深入了解一下，并向您展示它是多么的簡單!

1. 先創建PDF文件

// Create file with first page
try {
  BITMAPHANDLE page1 = { 0 };
  L_INT return_code = L_LoadBitmap(page1_file, &page1, sizeof BITMAPHANDLE, 24, ORDER_BGR, NULL, NULL);
  if(return_code < 1) throw(return_code);

  page1.XResolution = page1.YResolution = BITMAPHEIGHT(&page1) / 11; //set the DPI to cause 11 inch height.

  return_code = L_SaveBitmap(outputPdf_file, &page1, FILE_RAS_PDF_LZW, 24, 0, NULL);
  if(return_code < 1) throw(return_code);

  L_FreeBitmap(&page1);
}
catch (L_INT err) {
  cout << "Error Code: " << err;
}

2. 接下來，加載一個圖像并將其作為第二頁附加到同一個PDF文件中。

try {
  BITMAPHANDLE page2 = { 0 };
  L_INT return_code = L_LoadBitmap(page2_file, &page2, sizeof BITMAPHANDLE, 24, ORDER_BGR, NULL, NULL);
  if(return_code < 1) throw(return_code);

  SAVEFILEOPTION SaveOptions = { 0 };

  return_code = L_GetDefaultSaveFileOption(&SaveOptions, sizeof SAVEFILEOPTION);
  if(return_code < 1) throw(return_code);

  SaveOptions.PageNumber = 2;
  page2.XResolution = page2.YResolution = BITMAPHEIGHT(&page2) / 11; //set the DPI to cause 11 inch height.

  return_code = L_SaveBitmap(outputPdf_file, &page2, FILE_RAS_PDF_LZW, 24, 0, &SaveOptions);
  if(return_code < 1) throw(return_code);

  L_FreeBitmap(&page2);
}
catch (L_INT err) {
  cout << "Error Code: " << err;
}

BITMAPHANDLE page2_1 = { 0 }, page2_2 = { 0 };
// Load 2 images for one page
try {
  L_INT return_code = L_LoadBitmap(page2_1_file, &page2_1, sizeof BITMAPHANDLE, 24, ORDER_BGR, NULL, NULL);
  if(return_code < 1) throw(return_code);

  return_code = L_LoadBitmap(page2_2_file, &page2_2, sizeof BITMAPHANDLE, 24, ORDER_BGR, NULL, NULL);
  if(return_code < 1) throw(return_code);

  L_UINT w = max(BITMAPWIDTH(&page2_1), BITMAPWIDTH(&page2_2));
  L_UINT h = BITMAPHEIGHT(&page2_1) + BITMAPHEIGHT(&page2_2);
  BITMAPHANDLE combinedPage = { 0 };

  // Create empty bitmap
  return_code = L_CreateBitmap(&combinedPage, sizeof BITMAPHANDLE, TYPE_CONV, w, h, 24, ORDER_BGR, NULL, BOTTOM_LEFT, NULL, 0);
  if(return_code < 1) throw(return_code);

  // Copy the first image into the empty bitmap
  return_code = L_CombineBitmap(&combinedPage, 0, 0, BITMAPWIDTH(&page2_1), BITMAPHEIGHT(&page2_1), &page2_1, 0, 0, CB_DST_0 | CB_OP_ADD | CB_RAWCOMBINE, 0);
  if(return_code < 1) throw(return_code);

  L_FreeBitmap(&page2_1);

  // Copy the second image below the first image
  return_code = L_CombineBitmap(&combinedPage, 0, BITMAPHEIGHT(&page2_1), BITMAPWIDTH(&page2_2), BITMAPHEIGHT(&page2_2), &page2_2, 0, 0, CB_DST_0 | CB_OP_ADD | CB_RAWCOMBINE, 0);
  if(return_code < 1) throw(return_code);

  L_FreeBitmap(&page2_2);

  SaveOptions.PageNumber = 1;
  SaveOptions.Flags |= ESO_REPLACEPAGE; // add the replace flag to put the combined image instead of the old page1
  combinedPage.XResolution = combinedPage.YResolution = BITMAPHEIGHT(&combinedPage) / 11; //set the DPI to cause 11 inch height.

  return_code = L_SaveBitmap(outputPdf_file, &combinedPage, FILE_RAS_PDF_LZW, 24, 0, &SaveOptions);
  if(return_code < 1) throw(return_code);

  L_FreeBitmap(&combinedPage);
}
catch (L_INT err) {
  cout << "Error Code: " << err;
}