我的C＃循环在做什么错

Question

Ok so i have 2 lists

List<string> playlists 
List<string> sync

and the lets say the content of playlists is three strings

{"more and you", "and us", "more"}

and the content of sync is this

{"more and you-20120312", "more and you-20120314", "more and you-20120313",  "and us-20120313",  "and us-20120314",  "more-20120314",  "more-20120313", "more-20120312"}

Basically what i want to do is loop through all the loop through the playlists and find the associated syncs and print them out and they need to be 3 otherwise i want to color them differently..So here is my code so far

        StringBuilder sb = new StringBuilder();
        sb.Append("<h2>Playlist Information</h2>");
        foreach (string play in playlists)
        {
            int counter = 0;
            foreach (string s in sync)
            {
                if (s.StartsWith(play))
                {
                    sb.Append("<p class=\"good\">" + s + "</p>");
                    counter++;
                } 
            }
        }

So i want the final html to look like this

<h2>Playlist Information</h2>
<p class=\"good\">more and you-20120312</p>
<p class=\"good\">more and you-20120313</p>
<p class=\"good\">more and you-20120314</p>
<p class=\"bad\">and us-20120313</p>
<p class=\"bad\">and us-20120314</p>
<p class=\"good\">more-20120312</p>
<p class=\"good\">more-20120313</p>
<p class=\"good\">more-20120314</p>

the bad for the items that dont meet at least 3...any ideas on how to achieve this with my code

Answer 1

It is very easy to achieve this - just build another list during your check instead of the counter and then check the size of the "innerlist". I called it currentSyncSet:

    static void Main(string[] args)
    {
        List<string> playlists = new List<string>(){"more and you", "and us", "more"};
        List<string> sync = new List<string>() { "more and you-20120312", "more and you-20120314", "more and you-20120313", "and us-20120313", "and us-20120314", "more-20120314", "more-20120313", "more-20120312" };

        StringBuilder sb = new StringBuilder();
        sb.Append("<h2>Playlist Information</h2>\r\n");

        HashSet<string> finalSyncResult = new HashSet<string>();

        foreach (string play in playlists)
        {
            List<string> currentSyncSet = new List<string>();

            foreach (string s in sync)
            {
                if (s.StartsWith(play))
                {
                    currentSyncSet.Add(s);
                }
            }

            foreach (var syncset in currentSyncSet)
            {
                if (currentSyncSet.Count < 3)
                {
                    finalSyncResult.Add("<p class=\"bad\">" + syncset + "</p>");
                }
                else
                {
                    finalSyncResult.Add("<p class=\"good\">" + syncset + "</p>");
                }
            }
        }

        foreach (var result in finalSyncResult)
        {
            sb.Append(result + "\r\n");
        }

        Console.WriteLine(sb.ToString());

        Console.ReadKey();
    }

The Output is then:

<h2>Playlist Information</h2>
<p class="good">more and you-20120312</p>
<p class="good">more and you-20120314</p>
<p class="good">more and you-20120313</p>
<p class="bad">and us-20120313</p>
<p class="bad">and us-20120314</p>
<p class="good">more-20120314</p>
<p class="good">more-20120313</p>
<p class="good">more-20120312</p>

Greetings

Update 1: Sry, last time, i forgot, that you don't want to have duplicate entries - therefore i added a HashSet in this solution.