Question

我正在尝试使用itext生成pdf文件。我需要在最后一页的页脚上添加一个元素（段落）。我不知道如何将元素放在那个位置。

Answer 1

    #include <iostream>
    #include <fstream>
    #include <cstdlib>
    #include <vector>
    #include <string>

    using namespace std;

    void tokenize(string& str, vector<string>& tokens)
    {
        int pos;
        string token;
        while ((pos = str.find(" ")) != std::string::npos )
        {
            token = str.substr(0,pos);
            tokens.push_back(token); 
            str.erase(0, pos + 1);  
        }       
        tokens.push_back(str.c_str());  
    }

    bool isOperator(string str)
    {
        if((str == "+") || (str == "*") || (str == "/") )
            return true;
        else
            return false;
    }

    float compute(string oper, float val1, float val2)
    {
        if(oper == "+")
            return (val1 + val2);
        else if(oper == "*")
            return (val1 * val2);
        else if(oper == "/")
            return (val1 / val2); 
        else
            return 0;
    }

    void evalPrefix(vector<string>& expression)
    {
        vector<float> numStack;
        float num1;
        float num2;

        for (int i = (expression.size() - 1); i >=0; i--)
        {
            if(isOperator(expression[i]))
            {
                num1 = numStack.back();
                numStack.pop_back();
                num2 = numStack.back();
                numStack.pop_back();
                numStack.push_back(compute(expression[i], num1, num2));
            }
            else
            {
                numStack.push_back(atoi(expression[i].c_str()));
            }
        }
        int i = int (numStack[0] + 0.5);
        cout << i << endl;
    }



    int main(int argc, char *argv[]) 
    {
        ifstream file(argv[1]);
        string line;
        string token; 
        vector<string> tokens; 

        while (getline(file, line)) //processing the file
        {
            if(line.length() == 0)
                continue;
            else
            {
                tokens.clear();
                tokenize(line, tokens); //tokenizing the file
                if(tokens.size())
                    evalPrefix(tokens);
            }
        }
        return 0;
    }

并将标题装饰器添加到页面事件

import com.lowagie.text.Document;
import com.lowagie.text.DocumentException;
import com.lowagie.text.Element;
import com.lowagie.text.ExceptionConverter;
import com.lowagie.text.Image;
import com.lowagie.text.Phrase;
import com.lowagie.text.Rectangle;
import com.lowagie.text.pdf.PdfPCell;
import com.lowagie.text.pdf.PdfPTable;
import com.lowagie.text.pdf.PdfPageEventHelper;
import com.lowagie.text.pdf.PdfWriter;

public class PdfHeaderDecorator extends PdfPageEventHelper
{

  public PdfHeaderDecorator()
  {
    super();
  }

  public void onEndPage(PdfWriter writer, Document document)
  {
    PdfPTable tableF = new PdfPTable(3);

    try
    {

      tableF.setWidths(new int[]
      { 24, 24, 2 });
      tableF.setTotalWidth(527);
      tableF.setLockedWidth(true);
      tableF.getDefaultCell().setFixedHeight(9);
      tableF.getDefaultCell().setBorder(Rectangle.BOTTOM);
      tableF.addCell(new Phrase("SOME Text"));
      tableF.getDefaultCell().setHorizontalAlignment(Element.ALIGN_RIGHT);
      tableF.addCell(new Phrase(String.format("page %d ", writer.getPageNumber())));
      PdfPCell cell = new PdfPCell(new Phrase("bla bla bla"));
      cell.setBorder(Rectangle.BOTTOM);
      tableF.addCell(cell);
      tableF.writeSelectedRows(0, -1, 34, 30, writer.getDirectContent());

    }
    catch (DocumentException de)
    {
      throw new ExceptionConverter(de);
    }
  }
}

itext pdf：如何在页脚上方定位元素

1 个答案: