c# - Silverlight: Difficulty with binding to visiblity -

i have 2 elements: listbox , "this list empty" message. i'd bind visibility list box's itemssource being empty. however, i'm not sure how this:

        <textblock text="no favorite searches yet. add searching, clicking 'add favorites'"                     padding="10,0"                     verticalalignment="center"                    visibility="{binding path=favoritefilters.isempty, converter={staticresource visibilityconverter}}"                    />          <listbox itemssource="favoritefilters"                   x:name="favoritefilterslist"                   visibility="{binding path=favoritefilters.isempty, converter={staticresource visibilityconverter}}">             <listbox.itemtemplate>                 <datatemplate>                     <my:favoritefilterlink />                 </datatemplate>             </listbox.itemtemplate>         </listbox> 

they both visible, although itemssource empty. also, i'm not sure how invert condition listbox.

the visibility converter:

public class visibilityconverter : ivalueconverter {     public object convert(object value, type targettype, object parameter, system.globalization.cultureinfo culture)     {         if (value bool?)         {             if (string.isnullorempty((string)parameter))             {                 return (value bool?).value ? visibility.visible : visibility.collapsed;             } else             {                 return (value bool?).value ? visibility.collapsed : visibility.visible;             }         }         throw new argumentexception();     }      public object convertback(object value, type targettype, object parameter, system.globalization.cultureinfo culture)     {         throw new notimplementedexception();     } } 

you might better off writing 2 converters, 1 listbox other textblock. logic of each simpler , wouldn't need pass parameter correct result.

while might not elegant single converter solution far more maintainable.

if want pass parameter need use converterparameter.

there's example here i'm not 100% sure it'll meet requirements. simplified xaml syntax is:

<textblock visibility="{binding favoritefilters.isempty,      converter={staticresource visibilityconverter}, converterparameter=false}"/>  <listbox visibility="{binding favoritefilters.isempty,      converter={staticresource visibilityconverter}, converterparameter=true}"/> 

then in converter (simplified):

bool show = (bool)value; bool visible = (bool)parameter; if (visible) {     return show ? visibility.visible : visibility.collapsed; } else {     return show ? visibility.collapsed : visibility.visible; }