生成PDF图像重叠

Question

我有一个问题。我想从Listview表中生成一些图像并将其写入PDF。我曾经使用过ItextSharp，它的工作原理就像一个咒语-但是就现在而言，当用户添加一个依赖项时，它应该从数据库表中获取图像，然后转换为Image并保存为PDF

本部分可以100％

    private void button2_Click(object sender, EventArgs e)
    {
        using (SqlConnection con = new SqlConnection(constring))
        {
            con.Open();
            // string query = "select * from Base64TestTableW where id = @id";
            string query = "";
            using (SqlCommand cmd = new SqlCommand(query, con))
            {
                cmd.Parameters.AddWithValue("@id", id.Text);
                using (SqlDataReader rd = cmd.ExecuteReader())
                {
                    if (rd.Read())
                    {
                        string base64imgString = rd["base64String"].ToString();
                        byte[] finalBase64 = Convert.FromBase64String(base64imgString);
                        using (MemoryStream ms = new MemoryStream(finalBase64))
                        {
                            using (Stream inputPdfStream = new FileStream(@"C:\Users\emi\Desktop\Wema K2Service_HMO_Form (3).pdf", FileMode.Open, FileAccess.Read, FileShare.Read))
                            {
                                using (Stream outputPdfStream = new FileStream(@"C:\Users\emi\Desktop\pdfSharpExample\test2.pdf", FileMode.Create, FileAccess.Write, FileShare.None))
                                {
                                    var reader = new PdfReader(inputPdfStream);
                                    var stamper = new PdfStamper(reader, outputPdfStream);
                                    var pdfContentByte = stamper.GetOverContent(1);

                                    iTextSharp.text.Image image = iTextSharp.text.Image.GetInstance(finalBase64);
                                    image.SetAbsolutePosition(491.8f, 550f);
                                    pdfContentByte.AddImage(image);
                                    stamper.Close();
                                    MessageBox.Show("Good");
                                }
                            }
                        }
                    }

                }
            }
        }
    }

现在，当我想在PDF上使用相同的方法来获取其他依赖项时，而不是保存到PDF时，它们似乎相互重叠。此时，有关受抚养人的代码如下：

    private void GetChildImagePDFImage()
    {
        using (SqlConnection con = new SqlConnection(constring))
        {
            con.Open();
            string querychildpic = "select * from child_image where sid = @sid";
            using (SqlCommand cmd = new SqlCommand(querychildpic, con))
            {
                cmd.Parameters.AddWithValue("@sid", id.Text);
                using (SqlDataReader rdr = cmd.ExecuteReader())
                {
                    while (rdr.Read())
                    {
                        string base64imgString = rdr["base64String"].ToString();
                        byte[] finalBase64 = Convert.FromBase64String(base64imgString);

                        using (MemoryStream ms = new MemoryStream(finalBase64))
                        {
                            using (Stream inputPdfStream = new FileStream(@"C:\Users\emi\Desktop\Wema K2Service_HMO_Form (3).pdf", FileMode.Open, FileAccess.Read, FileShare.Read))
                            {
                                using (Stream outputPdfStream = new FileStream(@"C:\Users\emi\Desktop\pdfSharpExample\test2.pdf", FileMode.Create, FileAccess.Write, FileShare.None))
                                {
                                    var reader = new PdfReader(inputPdfStream);
                                    var stamper = new PdfStamper(reader, outputPdfStream);
                                    var pdfContentByte = stamper.GetOverContent(1);

                                    iTextSharp.text.Image image = iTextSharp.text.Image.GetInstance(finalBase64);
                                    image.SetAbsolutePosition(450f, 250f);
                                    image.SetAbsolutePosition(450f, 150f);
                                    image.SetAbsolutePosition(450f, 50f);
                                    pdfContentByte.AddImage(image);
                                    stamper.Close();
                                    MessageBox.Show("Good");
                                }
                            }
                        }
                    }
                }
            }
        }
    }

当放入For Loop中时，它会使PDF崩溃，我似乎不明白为什么会这样。

完整代码如下

using iTextSharp.text;
using iTextSharp.text.pdf;
using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Data.SqlClient;
using System.Drawing;
using System.IO;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using System.Windows.Forms;

namespace BrowseandPutImagePDF
{
    public partial class Form1 : Form
    {
        string constring = @"Data Source=DESKTOP-V2G35NU\SQLEXPRESS;Initial Catalog=base64ImageExample;Integrated Security=True";
        public Form1()
        {
            InitializeComponent();
        }

        private void button1_Click(object sender, EventArgs e)
        {
            OpenFileDialog openDialog = new OpenFileDialog();
            openDialog.Title = "Select A File";
            openDialog.Filter = "Text Files (*.txt)|*.txt" + "|" +
                                "Image Files (*.png;*.jpg)|*.png;*.jpg" + "|" +
                                "All Files (*.*)|*.*";
            if (openDialog.ShowDialog() == DialogResult.OK)
            {
                //textBox1.Text = openDialog.FileName;
            }
        }

        private void button2_Click(object sender, EventArgs e)
        {
            using (SqlConnection con = new SqlConnection(constring))
            {
                con.Open();
                // string query = "select * from Base64TestTableW where id = @id";
                string query = "";
                using (SqlCommand cmd = new SqlCommand(query, con))
                {
                    cmd.Parameters.AddWithValue("@id", id.Text);
                    using (SqlDataReader rd = cmd.ExecuteReader())
                    {
                        if (rd.Read())
                        {
                            string base64imgString = rd["base64String"].ToString();
                            byte[] finalBase64 = Convert.FromBase64String(base64imgString);
                            using (MemoryStream ms = new MemoryStream(finalBase64))
                            {
                                using (Stream inputPdfStream = new FileStream(@"C:\Users\emi\Desktop\Wema K2Service_HMO_Form (3).pdf", FileMode.Open, FileAccess.Read, FileShare.Read))
                                {
                                    using (Stream outputPdfStream = new FileStream(@"C:\Users\emi\Desktop\pdfSharpExample\test2.pdf", FileMode.Create, FileAccess.Write, FileShare.None))
                                    {
                                        var reader = new PdfReader(inputPdfStream);
                                        var stamper = new PdfStamper(reader, outputPdfStream);
                                        var pdfContentByte = stamper.GetOverContent(1);

                                        iTextSharp.text.Image image = iTextSharp.text.Image.GetInstance(finalBase64);
                                        image.SetAbsolutePosition(491.8f, 550f);
                                        pdfContentByte.AddImage(image);
                                        stamper.Close();
                                        MessageBox.Show("Good");
                                    }
                                }
                            }
                        }

                    }
                }
            }
        }

        private void GetChildImagePDFImage()
        {
            using (SqlConnection con = new SqlConnection(constring))
            {
                con.Open();
                string querychildpic = "select * from child_image where sid = @sid";
                using (SqlCommand cmd = new SqlCommand(querychildpic, con))
                {
                    cmd.Parameters.AddWithValue("@sid", id.Text);
                    using (SqlDataReader rdr = cmd.ExecuteReader())
                    {
                        while (rdr.Read())
                        {
                            string base64imgString = rdr["base64String"].ToString();
                            byte[] finalBase64 = Convert.FromBase64String(base64imgString);

                            using (MemoryStream ms = new MemoryStream(finalBase64))
                            {
                                using (Stream inputPdfStream = new FileStream(@"C:\Users\emi\Desktop\Wema K2Service_HMO_Form (3).pdf", FileMode.Open, FileAccess.Read, FileShare.Read))
                                {
                                    using (Stream outputPdfStream = new FileStream(@"C:\Users\emi\Desktop\pdfSharpExample\test2.pdf", FileMode.Create, FileAccess.Write, FileShare.None))
                                    {
                                        var reader = new PdfReader(inputPdfStream);
                                        var stamper = new PdfStamper(reader, outputPdfStream);
                                        var pdfContentByte = stamper.GetOverContent(1);

                                        iTextSharp.text.Image image = iTextSharp.text.Image.GetInstance(finalBase64);
                                        image.SetAbsolutePosition(450f, 250f);
                                        image.SetAbsolutePosition(450f, 150f);
                                        image.SetAbsolutePosition(450f, 50f);
                                        pdfContentByte.AddImage(image);
                                        stamper.Close();
                                        MessageBox.Show("Good");
                                    }
                                }
                            }
                        }
                    }
                }
            }
        }
    }
 }