Linq: how to select certain text “True” or “False” for corresponding boolean values?

Question

The following query is used to get data in which flagchecked is boolean.

var reducedList = alarmlog.Select(e => 
new { 
    e.ID, 
    e.alarmname, 
    e.alarmmessage, 
    e.metername, 
    e.starttime, e.flagchecked 
}).ToList();

I am using reducedList to export data to excel. Excel displays boolean values as checkboxes.I would like to have text "True" or "Done" for corresponding boolean true/false.

Answer 1

You could use the ternary/conditional operator: ?: Operator

var reducedList = alarmlog.Select(e => new 
{ 
    e.ID, 
    e.alarmname, 
    e.alarmmessage, 
    e.metername, 
    e.starttime, 
    flagchecked = e.flagchecked ? "Done" : "Not Done" }).ToList();

---

The conditional operator works like: condition ? first_expression : second_expression; condition ? first_expression : second_expression;

This means that: e.flagchecked ? "True" : "False"; e.flagchecked ? "True" : "False"; works the same as:

private string ConvertTrueFalseString(bool value)
{
    if(value)
        return "True";
    else
        return "False";
}

var reducedList = alarmlog.Select(e => new 
{ 
    e.ID, 
    e.alarmname, 
    e.alarmmessage, 
    e.metername, 
    e.starttime, 
    flagchecked = ConvertTrueFalseString(e.flagchecked)).ToList();

So, for this: e.flagchecked ? "Done" : "Not Done" e.flagchecked ? "Done" : "Not Done" . If (e.flagchecked == true) it returns "Done" and when (e.flagchecked == false) it returns "Not Done"

You might check the ?: Operator link I posted above.

Answer 2

var reducedList = alarmlog.Select(e => new {
    e.ID,
    e.alarmname,
    e.alarmmessage,
    e.metername,
    e.starttime,
    flagchecked = e.flagchecked ? "Done" : "Undone"
}).ToList();

Answer 3

reducedList.ForEach(x => x.flagchecked == "True" ? x.flagchecked = "Done" : x.flagchecked = "Undone");

您可以在实例化reducedList之后执行此reducedList 。