StreamReader sr = new StreamReader("data.txt", Encoding.Default);
//记得编码,不然读取汉字时会出错的
string text = sr.ReadToEnd();
string[] str= File.ReadAllLines("abc.txt");
//如果一定要用StreamReader可以这样写
using (StreamReader sr = new StreamReader("abc.txt"))
{
while (sr.Peek() >= 0)
{
Console.WriteLine(sr.ReadLine());
}
}