常规列表绑定到下拉列表

Posted 2021-02-25

/// <summary>
        /// Converts an IEnumberable to a list of SelectListItems
        /// </summary>
        /// <typeparam name="T">Type of items in data</typeparam>
 
        /// <typeparam name="TValueType">Type of property to be used for the Value property</typeparam>
        /// <typeparam name="TTextType">Type of property to be used for the Textproperty</typeparam>
        /// <param name="data">List to convert</param>
        /// <param name="defaultItem">An optional extra listItem appeneded at the beginning of the list</param>
        /// <param name="valueProperty">property of T to be used for the Value property</param>
        /// <param name="textProperty">property of T to be used for the Text property</param>
        /// <param name="selectedValue">Item in return value that should be selected</param>
        /// <returns></returns>
        public static List<SelectListItem> ToSelectList<T, TValueType, TTextType>(IEnumerable<T> data, SelectListItem defaultItem, Expression<Func<T, TValueType>> valueProperty, Expression<Func<T, TTextType>> textProperty, string selectedValue)
        {
            var list = new List<SelectListItem>();
 
            if (defaultItem != null)
            {
                list.Add(defaultItem);
            }
            if (data == null)
                return list;
 
            var memberInfo = textProperty.Body as MemberExpression;
            var textPropName = memberInfo.Member.Name;
 
            var valmemberInfo = valueProperty.Body as MemberExpression;
            var valuePropName = valmemberInfo.Member.Name;
 
 
            Type t = typeof(T);
 
            var textProp = t.GetProperties().Where(prop => prop.Name == textPropName).Single();
            var valueProp = t.GetProperties().Where(prop => prop.Name == valuePropName).Single();
 
            foreach (var item in data)
            {
 
                var text = textProp.GetValue(item, null);
                var value = valueProp.GetValue(item, null);
 
                list.Add(new SelectListItem()
                {
                    Text = text.ToString(),
                    Value = value.ToString(),
                    Selected = (selectedValue == value.ToString())
                }
                    );
            }
 
            return list;
        }