C# 代码审核
string xml = "<root><book>8899</book><age></age></root>";
XElement root = XElement.Parse(xml);
string strBook = root.Element("book").Value;
string strAge = root.Element("age").Value; //返回为"",而不是null
DataTable dt = new DataTable();
dt.Columns.Add("aa");
dt.Rows.Add(new object[]{DBNull.Value});
string aa = dt.Rows[0][0].ToString();//返回为"",而不是null
byte[] buf = new byte[1024*1024];
MemoryStream m = new MemoryStream(); //测试出来,memoryStream会自动释放的
for (int i = 0; i < 1024; i++)
{
m.Write(buf, 0, buf.Length);
}