[RESOLVED] Between

[met0555]

Hi, is there a way to show the text that is between something?
like this.
if i have this code

<input class="text" onClick='highlight(this);' value="[url=http://www.imgupp.com/uploads/pubtrick694407.jpg][/url]"

and i would like to show the text that are between [url and jpg] means http://www.imgupp.com/uploads/pubtrick694407

is there a way to do this?

tanks

[thingimijig]

You can use IndexOf to find url= and .jpg then substring

'find url= and add 4 because we want the string after it
        Dim start As Integer = yourstring.IndexOf("url=") + 4

        'find .jpg
        Dim finish As Integer = yourstring.IndexOf(".jpg")

        'show the string between the index's found
        MessageBox.Show(yourstring.Substring(start, finish - start))

[met0555]

when u say yourstring u mean the .jpg ... ?

[jmcilhinney]

He means the string that you want to get the substring of. "yourstring" means the string that you're using, i.e. your string.

[met0555]

Well, i've tried it as i understand it . And i've got this error

Length cannot be less than zero.
Parameter name: length

Dim mystring As String
        mystring = "mystring"
        'find url= and add 4 because we want the string after it
        Dim start As Integer = mystring.IndexOf("url=") + 4
 
        'find .jpg
        Dim finish As Integer = mystring.IndexOf(".jpg")
 
        'show the string between the index's found
        MessageBox.Show(mystring.Substring(start, finish - start))

[jmcilhinney]

Do you know what argument of what method that error message is talking about? What line did it occur on? What method on that line has an parameter named "length"? What is the value of that parameter when you call the method? How is that value calculated?

[met0555]

i know it's talking about

MessageBox.Show(mystring.Substring(start, finish - start))

[jmcilhinney]

So what about my other questions? This is how you solve problems. There isn't much code on that line so it shouldn't be too hard to work out which is the "length" parameter. Once you know that then you can check it's value. The error message says that it's less than zero and it's not allowed to be. How was it calculated? How did it get to be less than zero? Is it a data error or a logic error?

[met0555]

ok, i get what it was wrong, now my problem is i'm trying to select a text from an .html ("C:\tempsysfile.html") file, how do i do that?

[jmcilhinney]

HTML files are just plain text. You read them the same way(s) as any other text file.