Removing everything after the first " " in a string? (space)

Question

I am trying to remove everything after the first space in a string, now I have already tried this but it really doesn't work.

What did I try?

List<string> lines = new List<string>();

foreach (string textLine in richTextBox1.Lines)
{
    lines.Add(textLine.Substring(0, textLine.IndexOf(" ") + 1));
}

richTextBox1.Text = "";

foreach (string line in lines)
{
    richTextBox1.Text += line + Environment.NewLine;
}

String example:

some:kind of string   that I want      totrim please.

Now.. It SHOULD remove everything after "some:kind", why is it not? It's only trimming the occurance of the character at the end of each line, and only once.

What I am trying to split (proxy list)

83.71.175.121:8080  HTTP    NOA Ireland 30% (9) +   11-jul-2017 21:06
188.120.209.97:53281    HTTPS   HIA Czech Republic  70% (14) +  11-jul-2017 21:05
41.87.86.51:3128    HTTP    NOA Nigeria 64% (9) +   11-jul-2017 21:05
187.84.222.153:80   HTTP    ANM Brazil  61% (160) + 11-jul-2017 21:04
36.78.131.82:3128   HTTP    NOA Indonesia   25% (49) +  11-jul-2017 21:02
181.199.202.248:8080    HTTPS   NOA Spain   38% (35) +  11-jul-2017 21:01
180.253.231.211:8080    HTTPS   NOA Indonesia   new -   11-jul-2017 21:00
110.232.82.253:53695    SOCKS5  HIA Indonesia   60% (3) +   11-jul-2017 20:59
79.127.108.219:8080 HTTPS   NOA Iran, Islamic Republic of   41% (9) +   11-jul-2017 20:58
189.219.24.155:16057    SOCKS5  HIA Mexico  64% (7) +   11-jul-2017 20:58
189.218.237.10:52009    SOCKS5  HIA Mexico  64% (7) +   11-jul-2017 20:58
118.173.67.181:8080 HTTP    NOA Thailand    new +   11-jul-2017 20:55
38.123.201.17:8080  HTTPS   NOA United States   69% (25) +  11-jul-2017 20:55
81.128.165.5:3128   HTTP    ANM United Kingdom  53% (59) +  11-jul-2017 20:54
64.137.185.193:8080 HTTP    NOA Canada  new +   11-jul-2017 20:54
103.76.12.118:8080  HTTPS   NOA Indonesia   46% (75) +  11-jul-2017 20:54
209.141.47.120:80   HTTP    ANM United States   58% (97) +  11-jul-2017 20:53
109.230.100.255:9090    HTTPS   NOA Iran, Islamic Republic of   91% (135) - 11-jul-2017 20:52
180.250.174.251:8080    HTTPS   NOA Indonesia   29% (40) -  11-jul-2017 20:52
180.251.81.2:8080   HTTPS   HIA Indonesia   new +   11-jul-2017 20:51
151.80.197.192:80   HTTP    ANM France  50% (844) + 11-jul-2017 20:50
89.36.212.204:1189  HTTP    NOA France  100% (8) +  11-jul-2017 20:47
109.230.230.209:3128    HTTP    NOA Germany 100% (43) - 11-jul-2017 20:47
36.80.222.186:8080  HTTP    NOA Indonesia   new -   11-jul-2017 20:47
41.204.32.194:53281 HTTPS   HIA Ghana   58% (15) -  11-jul-2017 20:46
188.195.53.120:8080 HTTP    HIA Germany 50% (1) +   11-jul-2017 20:45

Answer 1

It would be simpler to do a string.Split() :

string input = "some:kind of string   that I want      totrim please."; 
input = input.Split()[0];
//input = "some:kind" now

I even added your sample input to my fiddle and it works flawlessly, fiddle here

Answer 2

Based on your data the issue is that you're looking for spaces, but the values are separated by tabs. So you need to use IndexOf('\t') instead. Alternatively the solution of using Split()[0] would also work as that will split on any white space including tabs.

Answer 3

尝试使用

lines.Add(textLine.Split(null)[0]);

Answer 4

Matching with a help of regular expresssion is yet another way:

string input = "some:kind of string   that I want      totrim please."; 

// @"^\s*\S*" if you want to ignore leading spaces
input = Regex.Match(input, @"^\S*").Value; 

which can be helpful when we want to get rid of part after whitespace (space, tabulation, non-breaking space etc.)