修改文本文件某一行数据的两种方法

1）File类

//找到setLocation
string[] ary = File.ReadAllLines(path, Encoding.Default);
ary = ary.Select(t => t.Trim().StartsWith("setLocation") ? setLocation : t.Trim()).ToArray();
File.WriteAllLines(path, ary, Encoding.Default);

2）StreamReader类

string text = "";
using (StreamReader reader = new StreamReader(path, Encoding.Default))
{
string line = reader.ReadLine();
while (line != null)
{
//如果这一行以setLocation开始，就替换原来的信息
if (line.StartsWith("setLocation"))
{
line = setLocation;
}
text += line + "
";
line = reader.ReadLine();
}
reader.Close();
reader.Dispose();
}
//写入流，更新数据
using (StreamWriter writer = new StreamWriter(path))
{
writer.Write(text);
writer.Close();
writer.Dispose();
}