/// <summary>
/// 将数据的List转化为下拉菜单数据List
/// </summary>
/// <typeparam name="T">源数据类</typeparam>
/// <param name="self">源数据List</param>
/// <param name="textField">指向text字段的表达式</param>
/// <param name="valueField">指向value字段的表达式</param>
/// <param name="selectedCondition">默认被选中的条件</param>
/// <returns>下拉菜单数据List</returns>
public static List <ComboSelectListItem> ToListItems <T>(this List <T> self
, Expression <Func <T, object> > textField
, Expression <Func <T, object> > valueField
, Expression <Func <T, bool> > selectedCondition = null)
{
var rv = new List <ComboSelectListItem>();
if (self != null)
{
//循环列表中的数据
foreach (var item in self)
{
//获取textField的值作为text
string text = textField.Compile().Invoke(item).ToString();
//获取valueField的值作为value
string value = valueField.Compile().Invoke(item).ToString();
//添加到下拉菜单List中
ComboSelectListItem li = new ComboSelectListItem
{
Text = text,
Value = value
};
//如果有默认选择的条件，则将当前数据带入到判断表达式中，如果返回true，则将下拉数据的selected属性设为true
if (selectedCondition != null)
{
if (selectedCondition.Compile().Invoke(item))
{
li.Selected = true;
}
}
rv.Add(li);
}
}
return(rv);
}
/// <summary>
/// 将枚举类型转化为下拉列表
/// </summary>
/// <param name="self">枚举类型</param>
/// <param name="value">value</param>
/// <param name="pleaseSelect">pleaseSelect</param>
/// <returns>下拉菜单数据列表</returns>
public static List <ComboSelectListItem> ToListItems(this Type self, object value = null)
{
string[] names = null;
Array values = null;
//如果是枚举
if (self.IsEnum)
{
names = Enum.GetNames(self);
values = Enum.GetValues(self);
}
//如果是nullable的枚举
if (self.IsGenericType && self.GenericTypeArguments[0].IsEnum)
{
names = Enum.GetNames(self.GenericTypeArguments[0]);
values = Enum.GetValues(self.GenericTypeArguments[0]);
}
//生成下拉菜单数据
List <ComboSelectListItem> rv = new List <ComboSelectListItem>();
if (names != null)
{
for (int i = 0; i < names.Length; i++)
{
var name = names[i];
var newitem = new ComboSelectListItem {
Text = PropertyHelper.GetEnumDisplayName(self, name), Value = ((int)values.GetValue(i)).ToString()
};
if (value is string)
{
if (value != null)
{
string v = value.ToString();
var vs = v.Split(',');
foreach (var item in vs)
{
if (item != null && (newitem.Value.ToString() == item.ToString()) || name == item.ToString())
{
newitem.Selected = true;
break;
}
}
}
}
else if (value is IEnumerable it)
{
foreach (var item in it)
{
if (item != null && name == item.ToString())
{
newitem.Selected = true;
break;
}
}
}
else
{
if (value != null && name == value.ToString())
{
newitem.Selected = true;
}
}
rv.Add(newitem);
}
}
return(rv);
}
