c# - Dual binding on Checkbox -

i have wpf application using mvvm. have ischecked value bound boolean on model instance on viewmodel. need bind method on viewmodel checked , unchecked events. (this can track unsaved changes , change background give users visual indication of need save. tried:

<checkbox      content="enable"      margin="5"      ischecked="{binding enabled}"      checked="{binding schedulechanged}"      unchecked="{binding schedulechanged}"     /> 

but 'provide value on 'system.windows.data.binding' threw exception.' error. advice?

here model working with:

    public class schedule : iequatable<schedule> {     private datetime _scheduledstart;     private datetime _scheduledend;     private bool _enabled;     private string _url;     public datetime scheduledstart     {         { return _scheduledstart; }         set         {             _scheduledstart = value;         }     }     public datetime scheduledend     {         { return _scheduledend; }         set         {             if(value < scheduledstart)             {                 throw new argumentexception("scheduled end cannot earlier scheduled start.");             }             else             {                 _scheduledend = value;             }         }     }     public bool enabled     {         { return _enabled; }         set { _enabled = value; }     }     public string url     {         { return _url; }         set { _url = value; }     }      public bool equals(schedule other)     {         if(this.scheduledstart == other.scheduledstart && this.scheduledend == other.scheduledend              && this.enabled == other.enabled && this.url == other.url)         {             return true;         }         else         {             return false;         }     } } 

my viewmodel contains property has observablecollection. itemscontrol binds collection , generates list. viewmodel sort of knows model instance, wouldn't know one, don't think.

you should able handle in setter enabled...

public class myviewmodel : viewmodelbase {      private bool _isdirty;     private bool _enabled;      public myviewmodel()     {         savecommand = new relaycommand(save, cansave);     }      public icommand savecommand { get; }      private void save()      {        //todo: add saving logic     }      private bool cansave()     {         return isdirty;     }      public bool isdirty     {          { return _isdirty; }        private set         {            if (_isdirty != value)             {                raisepropertychanged();             }        }     }      public bool enabled      {         { return _enabled; }         set         {            if (_enabled != value)            {                _enabled = value;                 isdirty = true;            }             //whatever code need raise inotifypropertychanged.propertychanged event            raisepropertychanged();         }     } } 

you're getting binding error because can't bind control event directly method call.

edit: added more complete example.

the example uses mvvm lite framework, approach should work mvvm implementation.