Question

C# DataTable

DataTable userTable = ds.Tables["Book"];
DataRow[] Rows = userTable.Select("BookID='"+bookid+"'");
foreach (DataRow row in Rows)
{
row.BeginEdit();
row["Count"] = row["Count"] - 1;
row.EndEdit();
}
不能自减？

Answer 1

DataTable userTable = ds.Tables["Book"];
DataRow[] Rows = userTable.Select("BookID='"+bookid+"'");
foreach (DataRow row in Rows)
{
row.BeginEdit();
row["Count"] = Convert.ToInt32(row["Count"]) - 1;// row["Count"]取出来是obj型。需要拆箱
row.EndEdit();
}