File 静态类 ReadAllBytes 和 WriteAllBytes ，用于一次性全部读取和写入小文件的字节码，
ReadLine ReadkAll 用于一次性全部读取字符（字符串）
FileStream 采用流的方式，适用于读取任意大小的文件的字节码,
static void CopyAvi(string source, string target) { using (FileStream fsReader = new FileStream(source, FileMode.OpenOrCreate, FileAccess.Read)) { using (FileStream fsWriter = new FileStream(target, FileMode.OpenOrCreate, FileAccess.Write)) { byte[] buffer = new byte[1024 * 1024 * 5]; while (true) { int length= fsReader.Read(buffer, 0, buffer.Length); if (length <= 0) { break; } fsWriter.Write(buffer, 0, length); } } } }
StreamReader和StreamWriter 采用流的方式，用于任意大小文件的字符操作
static void StreamReaderMethod(string path) { using (StreamReader sr = new StreamReader(path, Encoding.UTF8)) { while (!sr.EndOfStream) { Console.WriteLine( sr.ReadLine()); } } } static void StreamWriterMethod(string path) { using (StreamWriter sw = new StreamWriter(path)) { sw.WriteLine("看看有没有覆盖"); } }
File FileStream StreamReader和StreamWriter
原文：https://www.cnblogs.com/boentouch/p/12312173.html