DataTable与List集合转化

用于数据库查询数据转换、批量数据操作转换、导入导出Excel转换

public static class DataTableHelper
{
    /// <summary>
    /// 将DataTable对象转换成List对象
    /// </summary>
    /// <typeparam name="T">元数据类型</typeparam>
    /// <param name="table">DataTable类型的对象</param>
    /// <returns>返回List对象</returns>
    public static IList<T> ConvertTo<T>(DataTable table)
    {
        if (table == null)
            return null;

        List<DataRow> rows = table.Rows.Cast<DataRow>().ToList();

        return ConvertTo<T>(rows);
    }

    public static IList<T> ConvertTo<T>(IList<DataRow> rows)
    {
        IList<T> list = new List<T>();
        if (rows != null)
        {
            foreach (DataRow row in rows.Cast<DataRow>().ToList())
            {
                T obj = default(T);
                obj = Activator.CreateInstance<T>();
                foreach (DataColumn column in row.Table.Columns)
                {
                    var columnName = column.ColumnName;
                    var prop = obj.GetType().GetProperty(columnName);
                    if (prop == null) continue;
                    var value = (row[columnName] is DBNull) ? null : row[columnName];
                    if (prop.CanWrite)
                        prop.SetValue(obj, value, null);
                }
                list.Add(obj);
            }
        }
        return list;
    }

    /// <summary>
    /// 将IList对象转换成DataTable
    /// </summary>
    /// <typeparam name="T">类型</typeparam>
    /// <param name="list">源数据</param>
    /// <returns>返回DataTable</returns>
    public static DataTable ConvertTo<T>(IList<T> list)
    {
        DataTable dt = new DataTable();
        if (list.Count == 0)
            return dt;

        //创建table类型
        var t=Activator.CreateInstance<T>();
        dt.TableName = typeof(T).Name;

        PropertyInfo[] props=t.GetType().GetProperties();
        foreach (PropertyInfo p in props)
        {
            string propName = p.Name;
            Type propType=p.PropertyType;

            if (p.PropertyType.IsGenericType && p.PropertyType.GetGenericTypeDefinition() == typeof(Nullable<>))
            {
                propType = p.PropertyType.GetGenericArguments()[0];
            }
            dt.Columns.Add(propName,propType);
        }

        //赋值
        foreach (var item in list)
        {
            DataRow row = dt.NewRow();
            foreach (PropertyInfo p in props)
            { 
                var propValue=p.GetValue(item,null);
                row[p.Name] = propValue;
            }
            dt.Rows.Add(row);
        }

        return dt;
    }
}