Regular expression, back reference or alternate construct

I am trying to write a regular expression in .NET to capture the whole function from a list of functions that look something like this.

public string Test1()
{
    string result = null;
    foreach(var item in Entity.EntityProperties)
    {
        result +=string.Format("inner string with bracket{0}", "test");
    }
    return result;
}
public string Test5()
{
    return string.Format("inner string with bracket{0}", "test");
}

public string Last()
{
    return string.Format("inner string with bracket{0}", "test");
}

So I got

((?<function>public string (?<fName>\w+)\(\)\s*{.*?})(?=\s*public string))

This will capture all but the last function... or this

((?<function>public string (?<fName>\w+)\(\)\s*{.*?})(?=\s*(public string)|$))

This will match all functions correctly except the first one. The first function is only matched partially.

public string Test1()
{
    string result = null;
    foreach(var item in Entity.EntityProperties)
    {
        result +=string.Format("inner string with bracket{0}", "test");
    } <-- the first capture only get to this point.

Any idea? Please provide some explanation if possible.

It's actually possible to do it in .NET to check for matching bracket. The key is to use a balancing group. I've heard of it before that's why I ask the question. I just wasn't sure how to write the expression myself so I was hoping that some of the resident reg expert could help me out :)

Luckily I found this website. Which explain balancing group in details... he even provide a template. So here it is for everyone else reference.

http://blog.stevenlevithan.com/archives/balancing-groups the gist of the pattern is here

{
    (?>
        (?! { | } ) .
    |
        { (?<Depth>)
    |
        } (?<-Depth>)
    )*
    (?(Depth)(?!))
}

but check out his blog for the details explanation.