Question

我具有将一些数据写入二进制文件的功能

private void writeToBinFile (List<MyClass> myObjList, string filePath)
{
    FileStream fs = new FileStream(filePath, FileMode.Create);
    BinaryWriter bw = new BinaryWriter(fs);

    foreach (MyClass myObj in myObjList)
    {
        bw.Write(JsonConvert.SerializeObject(myObj));
    }
    bw.Close();
    fs.Close();

}

我看起来像

FileStream fs = new FileStream(filePath, FileMode.Create);
BinaryReader bw = new BinaryReader(fs);

while (!filePath.EOF)
{
    List<MyClass> myObjList = br.Read(myFile);
}

有人可以帮忙吗？预先感谢

Answer 1

JSON可以不带格式（没有新行）的形式保存，因此您可以在文件的每一行中保存1条记录。因此，我建议的解决方案是忽略二进制文件，而使用常规的StreamWriter：

private void WriteToFile(List<MyClass> myObjList, string filePath)
{
    using (StreamWriter sw = File.CreateText(filePath))
    {
        foreach (MyClass myObj in myObjList)
        {
            sw.Write(JsonConvert.SerializeObject(myObj, Newtonsoft.Json.Formatting.None));
        }
    }
}

private List<MyClass> ReadFromFile(string filePath)
{
    List<MyClass> myObjList = new List<MyClass>();
    using (StreamReader sr = File.OpenText(filePath))
    {
        string line = null;
        while ((line = sr.ReadLine()) != null)
        {
            myObjList.Add(JsonConvert.DeserializeObject<MyClass>(line));
        }
    }
    return myObjList;
}

如果您真的想使用二进制编写器保存JSON，则可以将其更改为如下形式：

private void WriteToBinFile(List<MyClass> myObjList, string filePath)
{
    using (FileStream fs = new FileStream(filePath, FileMode.Create))
    using (BinaryWriter bw = new BinaryWriter(fs))
    {
        foreach (MyClass myObj in myObjList)
        {
            bw.Write(JsonConvert.SerializeObject(myObj));
        }
    }
}

private List<MyClass> ReadFromBinFile(string filePath)
{
    List<MyClass> myObjList = new List<MyClass>();
    using (FileStream fs = new FileStream(filePath, FileAccess.Read))
    using (BinaryReader br = new BinaryReader(fs))
    {
        while (fs.Length != fs.Position) // This will throw an exception for non-seekable streams (stream.CanSeek == false), but filestreams are seekable so it's OK here
        {
            myObjList.Add(JsonConvert.DeserializeObject<MyClass>(br.ReadString()));
        }
    }
    return myObjList;
}

注意：

我在您的流实例化周围添加了using，以便在释放内存时正确关闭文件
要检查流的结尾，必须将Length与Position进行比较。

如何在C＃中读取二进制文件直到EOF

1 个答案: