string.ToString (IFormatProvider) doesnt take case of the provider ?

It's seem like a bug in the framework... but I'm not sure...
It's must seems weird, but I have a string variable and I want to apply a format and get the string formatted in that format. My original string is a numeric value and I want to obtain a string formatted based on the culture of the current thread.
string numericValue = "1234.56";
string returnValue = numericValue.ToString (System.Globalization.NumberFormatInfo.CurrentInfo);
But, it doesn't work. So, I check the code in the framework and there two methods ToString on the string Object. And both, return the this even the one with the provider parameter.

publicstringToString(IFormatProvider provider){returnthis;}

I you agree with me that there is a bug in the framework ?

hello.
i think that you're seeing it the wrong way.
what you want to do is get your number (ex.: double) and use the ToString method of that struct.
Double num = ...;
num.ToString( provider );
i think that using tostring with a provider on a string doesn't make any sense...

What I am trying to do is converting the format of a string from one culture to another. Say that you have a string 1 234,56 on the french-Canada culture and want to format the string to the english-US culture. I can parse the string to double and returning back to string. But I see that the string class have a method ToString who take a FormatProvider and do nothing with the parameter.

hello.

what i was trying to say is that if you're supposed to have a number, then use a variable of the desired type to keep it and parse it to the desired culture.

My simple solution is:
private void Form1_Load(object sender, EventArgs e)
{
double i = 1234.56;
textBox1.Text = i.ToString("0,000.00");

}