How do get the first occurrence of a char in Substring

Question

I'm trying to get the first occurrence in my substring start point:

string dir = Request.MapPath(Request.ApplicationPath) + "\\App_GlobalResources\\";

foreach (var file in Directory.EnumerateFiles(dir, "*.resx"))
{
    ddlResources.Items.Add(new ListItem { Text = file.Substring(firstoccuranceof("."), file.LastIndexOf(".")), Value = file });
}

if I do file.Substring(file.IndexOf("."), file.LastIndexOf(".")) I get an error

Answer 1

To answer your actual question - you can use string.IndexOf to get the first occurrence of a character. Note that you'll need to subtract this value from your LastIndexOf call, since Substring 's second parameter is the number of characters to fetch, not a start and end index.

However... Instead of parsing the names, you can just use Path.GetFilenameWithoutExtension to get the filename directly.

Answer 2

First occurence

String.IndexOf('.')

Last occurence

String.LastIndexOf('.')

Answer 3

Use IndexOf and LastIndexOf string methods to get index of first and last occurrence of "search" string. You may use System.IO.Path.GetExtension() , System.IO.Path.GetFileNameWithoutExtension() , and System.IO.Path.GetDirectoryName() methods to parse the path.

For instance,

string file = @"c:\csnet\info.sample.txt";
Console.WriteLine(System.IO.Path.GetDirectoryName(file));           //c:\csnet
Console.WriteLine(System.IO.Path.GetFileName(file));                //info.sample.txt
Console.WriteLine(System.IO.Path.GetFileNameWithoutExtension(file));//info.sample
Console.WriteLine(System.IO.Path.GetExtension(file));               //.txt

Answer 4

file.IndexOf(".")

Should get you the first occurence of ".". Otherwise it will return -1 if not found.

Answer 5

I think that in your particular case you are NOT trying to get IndexOf... Instead you need to use 0 because you are trying to create a key based on filename if understand correctly:

`ddlResources.Items.Add(new ListItem(file.Substring(0, file.LastIndexOf(".")), file ));`

Also, you have '{}' in there as in new ListItem { ... } which is also going to cause a syntax error... Anyhow have a look..

Answer 6

Because the original question is marked with the [regex] tag, I'll provide the following solution, however the best answer for simple parsing of paths using .NET is not by regex.

//extracts "filename" from "filename.resx"
string name = Regex.Match("filename.resx", @"^(.*)\..+?$").Groups[1].Value; 

Use an answer that relies on the Path class instead, for simplicity. Other answers contain that info.