把List<T>轉換為DataTable

下麵這個學習，把List<T>轉換為Datatable。

下麵先創建一個對象T:

class Ay
    {
        private int _ID;
        public int ID
        {
            get { return _ID; }
            set { _ID = value; }
        }

        private string _Account;
        public string Account
        {
            get { return _Account; }
            set { _Account = value; }
        }

        private string _Email;
        public string Email
        {
            get { return _Email; }
            set { _Email = value; }
        }

        public Ay()
        {

        }

        public Ay(int id,string account,string email)
        {
            this._ID = id;
            this._Account = account;
            this._Email = email;
        }
    }

此時，你可以寫一個C#擴展方法：

public static DataTable ToDataTable<T>(this List<T> items)
        {
            DataTable dataTable = new DataTable();
           
            PropertyInfo[] Props = typeof(T).GetProperties(BindingFlags.Public | BindingFlags.Instance);
            foreach (PropertyInfo prop in Props)
            {                
                dataTable.Columns.Add(prop.Name);
            }

            foreach (T obj in items)
            {
                var values = new object[Props.Length];
                for (int i = 0; i < Props.Length; i++)
                {
                    values[i] = Props[i].GetValue(obj, null);
                }
                dataTable.Rows.Add(values);
            }

            return dataTable;
        }

下麵，我們在List<T>添加幾筆記錄，然後使用上面的擴展方法，把List<T> 轉換為DataTable.
為了看到結果，再把DataTable列印至控制臺上：

class Az
    {
        public void ConvertListToDataTableTextDemo()
        {
            List<Ay> ays = new List<Ay>()
            {
                new Ay() { ID=1,Account="A0001",Email="[email protected]" },
                new Ay() { ID=2,Account="A0002",Email="[email protected]"},
                new Ay() {ID=3,Account="A0003",Email="[email protected]" }
            };

          DataTable dt =  ays.ToDataTable();

            foreach (DataRow row in dt.Rows)
            {
                Console.WriteLine();
                for (int x = 0; x < dt.Columns.Count; x++)
                {
                    Console.Write(row[x].ToString() + " ");
                }
            }

            Console.WriteLine("\n\r");

        }
    }

控制台輸出的結果：