where T:new() 約束類型參數至少有一個無參構造函數
使用場景 : 無意中使用new T 引發了new() 約束的實際使用
例子:
private IEnumerable<T> FormatProductProcessDayOutputData<T>(IEnumerable<T> qry) where T : vw_ProductProcess_DayOutputData, new()
{
var list = qry.Select(x => new T
{
class_date = x.class_date,
D1_count = x.D1_count,
D234_count = x.D234_count,
D2_count = x.D2_count,
D3_count = x.D3_count,
D4_count = x.D4_count,
D5_count = x.D5_count,
is_social_security_card = x.is_social_security_card == "1" ? "社保" : "非社保"
});
return list;
}