using System;
using System.Collections.ObjectModel;
using System.Data;
using System.Reflection;

namespace formula_manage.UserClass
{
    internal class DataTableToObservableCollection //数据表到可观察集合
    {
        public ObservableCollection<T> ToObservableCollection<T>(DataTable dt) where T : class, new()
        {
            Type t = typeof(T);
            PropertyInfo[] propertys = t.GetProperties();
            ObservableCollection<T> lst = new ObservableCollection<T>();
            string typeName = string.Empty;
            foreach (DataRow dr in dt.Rows)
            {
                T entity = new T();
                foreach (PropertyInfo pi in propertys)
                {
                    typeName = pi.Name;
                    if (dt.Columns.Contains(typeName))
                    {
                        if (!pi.CanWrite) continue;
                        object value = dr[typeName];
                        if (value == DBNull.Value) continue;
                        if (pi.PropertyType == typeof(string))
                        {
                            pi.SetValue(entity, value.ToString(), null);
                        }
                        else if (pi.PropertyType == typeof(int) || pi.PropertyType == typeof(int?))
                        {
                            pi.SetValue(entity, int.Parse(value.ToString()), null);
                        }
                        else if (pi.PropertyType == typeof(DateTime?) || pi.PropertyType == typeof(DateTime))
                        {
                            pi.SetValue(entity, DateTime.Parse(value.ToString()), null);
                        }
                        else if (pi.PropertyType == typeof(float))
                        {
                            pi.SetValue(entity, float.Parse(value.ToString()), null);
                        }
                        else if (pi.PropertyType == typeof(double))
                        {
                            pi.SetValue(entity, double.Parse(value.ToString()), null);
                        }
                        else
                        {
                            pi.SetValue(entity, value, null);
                        }
                    }
                }
                lst.Add(entity);
            }
            return lst;
        }

    }
}