通过以下方法可以逐行查找并替换内容。
private void UpdateContentInFile(string file, string o_str, string n_str)
{StringBuilder strB = new StringBuilder();
using(FileStream fin = new FileStream(file, FileMode.Open, FileAccess.Read))
using(StreamReader sr = new StreamReader(fin))
try
{
string line = sr.ReadLine();
if (line.Contains(o_str))
{
line = n_str;
}