wpf - Can't understand Error in XAML Converter -

i use converter "convert" width. want make 10% of "parent" width. use parameter value "0.1" (10%). in converter value converted "1.0". dont know why (see picture below).

percentageconverter.cs

    using system;     using system.windows.data;      namespace erdbuilder.shell.converter     {         public class percentageconverter : ivalueconverter         {             public object convert(object value,                 type targettype,                 object parameter,                 system.globalization.cultureinfo culture)             {                 double dblvalue = system.convert.todouble(value);                 double dblparameter = system.convert.todouble(parameter);                 double val = dblvalue*dblparameter;                 return val;             }              public object convertback(object value,                 type targettype,                 object parameter,                 system.globalization.cultureinfo culture)             {                 throw new notimplementedexception();             }         }     } 

corestyles.xaml

    ...     xmlns:converter="clr-namespace:erdbuilder.shell.converter"     ...     <converter:percentageconverter x:key="percentageconverter" />     ...     <border x:name="trackrectangle" height="15">         <border background="steelblue" width="{binding converter={staticresource percentageconverter},elementname=trackrectangle,path=actualwidth,converterparameter=0.1}"/>     </border> 

i dont understand this

fixed solution - error in interpreting correct delimiter (have replace '.' against ','):

percentageconverter.cs

    double dblparameter = system.convert.todouble(((string)parameter).replace('.',',')); 

instead of

    double dblparameter = system.convert.todouble(parameter);