Optimize loop in ASP.Net / C#

Question

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 + "<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.

@CD No, `String.Join Method (String, IEnumerable). He already has a `List` — xanatos, Sep 01 '11 at 11:44
read this article http://www.codeproject.com/KB/cs/StringBuilder_vs_String.aspx — Nahum, Sep 01 '11 at 12:05

score 5 · Accepted Answer · edited May 23 '17 at 12:29

5

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?)

edited May 23 '17 at 12:29

Community

1
1

answered Sep 01 '11 at 11:43

CD..

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Thanks a lot :) I used this one and the one answered by SBlackler. Both are working great ! – Maverick Sep 01 '11 at 13:22
Admittedly, I didn't know about `String.Join` in this way +1 – Stuart Blackler Sep 01 '11 at 14:54

Stuart Blackler · Answer 2 · 2011-09-01T11:48:39.797

4

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

edited Sep 01 '11 at 11:48

answered Sep 01 '11 at 11:38

Stuart Blackler

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Thanks a lot :) I used this one and the one answered by CD. Both are working great – Maverick Sep 01 '11 at 13:22

score 0 · Answer 3 · answered Sep 01 '11 at 11:34

0

You should be using a StringBuilder.

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

answered Sep 01 '11 at 11:34

George Duckett

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George, sorry: I red your comment and started to write an answer... but you are the first, so do you prefer I delete my answer? :) – Marco Sep 01 '11 at 11:37

score 0 · Answer 4 · answered Sep 01 '11 at 11:43

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);
            });

Optimize loop in ASP.Net / C#

4 Answers4