Sort in list object

Question

I get from database Sytem.Collections.generic.IList and filter it by searchText:

String searchText="E";
var query = something().List();
query = query.Where(x => !string.IsNullOrEmpty(x.Name) &&
x.Name.ContainsInsensitive(searchText)).ToList();
result = query.Select().ToList();

Now I would like that result is sorted by Name column. First all values which starts with searchText and then all values which contains searchText.

If I write this:

result = result.OrderBy(x => x.Name).ToList();

I get result sorted by Name, for example:

1. "A name"    
2. "B name"
3. "E name"
4. "F name"

All this contains e in Name. I would like that my sort is:

1. "E name"    
2. "A name"
3. "B name"
4. "F name"

What should I change in my OrderBy expression?

Answer 1

Chain together 2 orders with OrderBy and ThenBy

.OrderBy(x => x.Name.StartsWith(searchText) ? 0 : 1)
.ThenBy(x => x.Name)

Answer 2

You can do two sorting calls after another (first OrderBy, all subsequent ThenBy):

result.OrderBy(x => !x.Name.StartsWith(searchText)).ThenBy(x => x.Name).ToList();

This will sort true (1) first, then (0) false. The !x.Name makes the order right. Then it sorts on x.Name in both groups.

Answer 3

Well, according your code you have result materialized as List<T>:

 result = query.Select().ToList();

And then you're recreating and reassigning the list:

 result = result.OrderBy(x => x.Name).ToList();

So I suggest sorting in-place instead of OrderBy:

  result.Sort((x, y) => {
    if (x.Name.StartsWith(searchText)) {
      if (!y.Name.StartsWith(searchText))
        return 1;
    } 
    else if (y.Name.StartsWith(searchText))
      return -1;

    return String.Compare(x.Name, y.Name);
  });