c#操作文本文件

读:TextBox1.Text=File.ReadAllText("d:/b.txt",Encoding.Default);
写:File.WriteAllText("d:/a.txt", TextBox1.Text, Encoding.Default);
追加:File.AppendAllText("d:/a.txt", TextBox1.Text, Encoding.Default);

程序集中指定路径：EnsurePathExists(Path.Combine(AppDomain.CurrentDomain.BaseDirectory, "submit"));

判断路径：

void EnsurePathExists(string path){if (!Directory.Exists(path))Directory.CreateDirectory(path);}