使用iTextSharp将多幅图像转换为PDF

Question

我正在尝试转换一系列的图像从OpenFileDialog()到一个PDF使用C#中的iTextSharp。这就是我正在运行的。当我选择文件时，我得到错误："System.NotSupportedException: 'Stream does not support reading.'"

在线上：

var image = iTextSharp.text.Image.GetInstance(imageStream);

我想知道这个错误意味着什么，或者我可以修复什么来解决这个问题。谢谢。

namespace WindowsFormsApp2
{

public partial class Form1 : Form
{
    public Form1()
    {
        InitializeComponent();
    }

    private OpenFileDialog ofd = new OpenFileDialog { Multiselect = true, Filter = "Image files | * .jpg;*.jpeg;*.png;" };

    // Open file button
    private void button1_Click(object sender, EventArgs e)
    {
        // Run code only if a file is selected
        if (ofd.ShowDialog() == DialogResult.OK)
        {
            Document doc = new Document();
            using (var stream = new FileStream("test.pdf", FileMode.Create, FileAccess.Write, FileShare.None))
            {
                foreach (String file in ofd.SafeFileNames)
                {
                    using (var imageStream = new FileStream(file, FileMode.Open, FileAccess.Read, FileShare.ReadWrite))
                    {
                        PdfWriter.GetInstance(doc, stream);
                        doc.Open();
                        var image = iTextSharp.text.Image.GetInstance(imageStream);
                        doc.Add(image);
                        doc.Close();
                    }


                }
            }


        }
    }
}
}

下面是主要代码：

namespace WindowsFormsApp2
{
    static class Program
    {
        /// <summary>
        /// The main entry point for the application.
        /// </summary>
        [STAThread]
        static void Main()
        {
            Application.EnableVisualStyles();
            Application.SetCompatibleTextRenderingDefault(false);
            Application.Run(new Form1());
        }
    }
}

Answer 1

尝试下面的代码，我已经将doc的开始和结束移到了foreach循环之外。调用doc.Close()会关闭父文件流，因此只有在添加完所有图像后才调用doc.Close()非常重要。

using (var stream = File.Create("test.pdf"))
using (var doc = new Document())
using (var pdfWriter = PdfWriter.GetInstance(doc, stream))
{
    doc.Open();

    foreach (var file in ofd.SafeFileNames)
    {
        using (var imageStream = File.OpenRead(file))
        {
            var image = Image.GetInstance(imageStream);
            doc.Add(image);
        }
    }

    doc.Close();
}