C# 取得文字檔中的內容

// Get file content string
public string FileContent(string fileName)
{

StreamReader stmRdr = new StreamReader(fileName);
string line = stmRdr.ReadLine();
string sLine = null;

while (line != null)
{
if (line.Length != 0)
sLine = sLine + line + '\n';
line = stmRdr.ReadLine();
}
stmRdr.Close();
return sLine;
}