How to change line in text file in C#?

Question

Currently I inform in variable stringantiga the exact value to find and replace it.

Is there any way to substitute for the line number instead of the exact value of stringantiga?

string arquivo = ConfigurationSettings.AppSettings["Caminho"].ToString();
string stringbusca = "MaxChannelInUse";
string stringantiga = "MaxChannelInUse=80";
string stringnova = "MaxChannelInUse=90000";
StreamReader sr = new StreamReader(arquivo);
StringBuilder sb = new StringBuilder();

while (!sr.EndOfStream)
{
    string s = sr.ReadLine();
    if (s.IndexOf(stringbusca) > -1)
    {
        s = s.Replace(stringantiga, stringnova);
    }
    sb.AppendLine(s);
}
sr.Close();

StreamWriter sw = new StreamWriter(arquivo);
sw.Write(sb);

sw.Close();

Answer 1

Yes. You can simply read the entire file using the method File.ReadAllLines(), change the line and then write to the file using the method File.WriteAllLines().

var arquivo = ConfigurationSettings.AppSettings["Caminho"].ToString();
var linhas = File.ReadAllLines(arquivo);

arquivo[0] = "Novo conteúdo"; // Editar a primeira linha

File.WriteAllLines(arquivo, linhas);