Optimize loop in ASP.Net / C#

I wrote a loop to display each line one by one from a List of string. The problem is that the list contains more that 45,000 lines and its taking a lot of time to create the page for displaying.

Can someone please help in optimizing the code !

        List<string> OverrrideLog = lc.getOverrideLog();
        List<string> AccessLog = lc.getAccessLog();

        foreach (string s in OverrrideLog)
            lblOverrideLog.Text += s + 开发者_JAVA技巧"<br/>";

        foreach (string s in AccessLog)
            lblAccessLog.Text += s + "<br/>";

Here lblOverrideLog and lblAccessLog are literals and each list has more than 22,000 lines.

You can use the String.Join Method (String, IEnumerable):

List<string> OverrrideLog = lc.getOverrideLog();
List<string> AccessLog = lc.getAccessLog();

lblOverrideLog.Text = String.Join("<br />", OverrrideLog);
lblAccessLog.Text = String.Join("<br />", AccessLog);

(See also String.Join vs. StringBuilder: which is faster?)

Untested but try this:

List<string> OverrrideLog = lc.getOverrideLog();
List<string> AccessLog = lc.getAccessLog();

StringBuilder sb = new StringBuilder();
StringBuilder sb2 = new StringBuilder();

foreach(var el in OverrrideLog)
{
  sb.Append(el);
  sb.Append(" <br />");
}

foreach(var el in AccessLog)
{
  sb2.Append(el);
  sb2.Append(" <br />");
}

lblOverrideLog.Text = sb.ToString();
lblAccessLog.Text = sb2.ToString();

Edit:

woops, put val instead of var

You should be using a StringBuilder.

Concatenating strings like you are creates thousands of temporary ones in memory.

for a exsample

            OverrrideLog.ForEach(x=>{
                if (sbOverrideLog.Length > 0)
                    sbOverrideLog.Append("<br />");

                sbOverrideLog.Append(x);
            });

            AccessLog.ForEach(x =>
            {
                if (sbAccessLog.Length > 0)
                    sbAccessLog.Append("<br />");

                sbAccessLog.Append(x);
            });