c# 二进制读取器 System.InvalidCastException：

Question

我得到的错误是。

System.InvalidCastException: '无法将类型为'project.Book[]'的对象转换为类型'project.Book'。'

就目前而言，当我尝试打开文件并将其显示在我的 WinForms 应用程序中时，我在保存文件时没有任何错误，我遇到了这个错误，我已经检查了其他帖子以解决这个问题，将数据保存到一个对象中，然后再到一维数组，但找不到与此问题相关的任何细节。

这是我的课本

    [Serializable]
    class Book
    {
        private string author;
        private string title;
        private string publisher;
        private double price;
        private string date;
        private int ISBN;

        //vehcicle constructor
        public Book()
        { }
        //overloaded constructor
        public Book(int bookISBN, string bookAuthor, string bookTitle, string bookPublisher, double bookPrice, string bookDate)
        {
            ISBN = bookISBN;
            author = bookAuthor;
            title = bookTitle;
            publisher = bookPublisher;
            price = bookPrice;
            date = bookDate;
        }
        public int gsISBN
        {
            get { return ISBN; }
            set { ISBN = value; }
        }
        public string gsAuthor//author getter and setter
        {
            get { return author; }
            set { author = value; }
        }
        public string gsTitle//title getter and setter
        {
            get { return title; }
            set { title = value; }
        }
        public string gsPublisher//publisher getter and setter
        {
            get { return publisher; }
            set { publisher = value; }
        }
        public double gsPrice//price getter and setter
        {
            get { return price; }
            set { price = value; }
        }
        public string gsDate//date getter and setter
        {
            get { return date; }
            set { date = value; }
        }
        public string Printbook()//Printbook string for the base constructor
        {
            return gsISBN + " - " + gsAuthor + ", " + gsTitle;

        }
    }

这是我的二进制写入/读取。

private void SaveBinaryBook()
        {

            FileStream fs = new FileStream("Book.dat", FileMode.Create);

            // Construct a BinaryFormatter and use it to serialize the data to the stream.
            BinaryFormatter formatter = new BinaryFormatter();
            try
            {
                //myBooks is the array 
                formatter.Serialize(fs, myBooks);

            }
            catch (SerializationException e)
            {
                Console.WriteLine("Failed to serialize. Reason: " + e.Message);
                throw;
            }
            finally
            {
                fs.Close();
            }
        }

  private void LoadBinaryBook()
        {


            // Open the file containing the data that you want to deserialize.
            FileStream fs = new FileStream("Book.dat", FileMode.Open);
            try
            {
                BinaryFormatter formatter = new BinaryFormatter();

                // Deserialize the hashtable from the file and 
                // assign the reference to the local variable.
                Book book = (Book)formatter.Deserialize(fs);
                currentIndexBook++;
                DisplayBook();
            }
            catch (SerializationException e)
            {
                MessageBox.Show("Failed to deserialize. Reason: " + e.Message);
                throw;
            }
            finally
            {
                fs.Close();
            }
        }

我是新来的，这一切都是为了一个任务，所以任何帮助将不胜感激。

Answer 1

LoadBinaryBook这一行：

Book book = (Book)formatter.Deserialize(fs);

Deserialize方法返回Book （所以Book[] ）对象的数组，但您试图将其转换为单个Book 。 因为在SaveBinaryBook ：

//myBooks is the array 
formatter.Serialize(fs, myBooks);

在LoadBinaryBook您还需要反序列化为数组：

Book[] books = (Book[])formatter.Deserialize(fs);