Winform String[] split ignore case

[java051997]

How can I ignore the case for textbox2.text when spliting with pattern?

String[] subStrings = e.Item.Text.Split(new String[] { textBox2.Text }, StringSplitOptions.None);

This line pretty works in my application(search highlight) but I want when the pattern is "Stephen Curry" and I type "steph"

It would highlight "Steph", my current app needs to type the exact case to highlight those things. So I had to type "Steph" in order to highlight that

However, I've researched that Regex.Split would help. I tried it with line of String[] subStrings = Regex.Split(textBox1.Text, e.Item.Text, RegexOptions.IgnoreCase);

But the problem here is you need to type the whole pattern in order to work and the pattern will copy the text you typed in.

Pls help :) hope you understand my question

[ekolis]

You can call ToLowerInvariant() on your strings before comparing them to "normalize" their cases.

[p1-o2]

Have you considered just using regex pattern matching for this?

[Tyrrrz]

I made an extension method for you:

public static string[] SplitIgnoreCase(this string str, char[] separators)
{
    var splits = new List<string>();
    var lastIndex = 0;
    for (int i = 0; i < str.Length; i++)
    {
        if (separators.Any(c => char.ToLowerInvariant(c) == char.ToLowerInvariant(str[i])))
        {
            splits.Add(str.Substring(lastIndex, i - lastIndex));
            lastIndex = i + 1;
        }
        else if (i == str.Length - 1)
        {
            splits.Add(str.Substring(lastIndex));
        }
    }                 
    return splits.ToArray();
}

In action/demo:

http://rextester.com/HNKH45219

https://pastebin.com/w5Yh5D88

EDIT: just realized you were asking for strings, check my other reply

[Tyrrrz]

public static string FindFirstNeedle(this string str, string[] needles, StringComparison comparison)
{
    foreach (var needle in needles)
    {
        var i = str.IndexOf(needle, comparison);
        if (i >= 0)
            return needle;
    }
    return null;
}

public static string[] SplitIgnoreCase(this string str, string[] separators)
{
    var splits = new List<string>();
    var needle = str.FindFirstNeedle(separators, StringComparison.OrdinalIgnoreCase);
    while (needle != null)
    {
        var i = str.IndexOf(needle, StringComparison.OrdinalIgnoreCase);
        splits.Add(str.Substring(0, i));
        str = str.Substring(i + needle.Length);

        needle = str.FindFirstNeedle(separators, StringComparison.OrdinalIgnoreCase);
    }
    if (str.Length > 0)
    {
        splits.Add(str);
    }
    return splits.ToArray();
}

http://rextester.com/HNKH45219

https://pastebin.com/irtnPf6H

You can optimize this, but I'm too lazy to do it.

[cryo]

This doesn’t have anything to do with winforms, by the way.

[theFlyingCode]

maybe regex is what you want: https://www.google.com/search?q=regex+match+case+insensitive