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using Custom Formatter when format is unknown at design time

Posted By:      Posted Date: September 07, 2010    Points: 0   Category :.NET Framework
I have class "CF" that implements IFormattable interface. I can convert it to string var cf = new CF(); string str = cf.ToString("MYFORMAT", CultureInfo.InvariantCulture) or str = String.Format("{0:MYFORMAT}", cf);   the problem is that "MYFORMAT" is a parameter. so i can still use string fmt = "FORMAT"; string str = cf.ToString(fmt, CultureInfo.InvariantCulture) Is it possible still use String.Format for formatting? That doesnt work str = String.Format("{0:{1}}", cf, format)      

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