c# - Applying a filter in ViewModel when value from the ViewModel change -

i have bind twice data on application. have 2 list view. first 1 list of element present checkbox. second list view have value checkbox checked.

so tried deal viewmode , 2 observablecollection. 1 full , 1 filtered. dont work. way ?

thank you!

here xaml code :

<!-- full collection --> <listview grid.row="1" grid.column="0" itemssource="{binding cycles.mydata}">     <listview.view>         <gridview allowscolumnreorder="false">             <gridviewcolumn>                 <gridviewcolumn.celltemplate>                     <datatemplate>                         <checkbox style="{dynamicresource switchonly}" ischecked="{binding cycles.used, updatesourcetrigger=propertychanged}"/>                     </datatemplate>                 </gridviewcolumn.celltemplate>             </gridviewcolumn>             <gridviewcolumn>                 <gridviewcolumn.celltemplate>                     <datatemplate>                         <textblock text="{binding name}"/>                     </datatemplate>                 </gridviewcolumn.celltemplate>         </gridviewcolumn>     </gridview> </listview.view> <!-- filtered collection --> <listview grid.column="2" grid.row="0" grid.rowspan="2" itemssource="{binding cycles.mydatafiltered}">     <listview.view>         <gridview allowscolumnreorder="false">             <gridviewcolumn>                  <gridviewcolumn.celltemplate>                      <datatemplate>                          <checkbox style="{dynamicresource visualonly}" ischecked="{binding check}"/>                      </datatemplate>                  </gridviewcolumn.celltemplate>              </gridviewcolumn>              <gridviewcolumn>                  <gridviewcolumn.celltemplate>                      <datatemplate>                          <textblock text="{binding name}"/>                      </datatemplate>                  </gridviewcolumn.celltemplate>              </gridviewcolumn>          </gridview>      </listview.view>  </listview> 

here viewmodel :

public class viewmodel : propertychangedbase {     public observablecollection<cycles> mydata { get; set; }     public observablecollection<cycles> mydatafiltered { get; set; }      private bool _used = true;     public bool used     {         => _used;         set         {             _used = value;             _mydataview.filter = filter;             onpropertychanged("used");         }     }      private cycles _currentselectedcycle;     public cycles currentselectedfamily     {         => _currentselectedcycle;         private set         {             _currentselectedcycle = value;             onpropertychanged("currentselectedfamily");         }     }       readonly icollectionview _mydataview;      public viewmodel()     {         mydata = new observablecollection<cycles>();         mydatafiltered = new observablecollection<cycles>();         _mydataview = collectionviewsource.getdefaultview(mydatafiltered);         _mydataview.currentchanged += delegate         {             currentselectedfamily = (cycles)_mydataview.currentitem;         };     }     private static bool filter(object item)     {         var value = (cycles)item;         return value != null && value.check;     } } 

here cycle class :

public class cycles : propertychangedbase {     internal cycles()     {         _check = false;         _firstday = 1;     }      private bool _check;     private string _name;     private int _firstday;     private int _lastday;      public bool check     {         => _check;         set         {             if (_check == value) return;             _check = value;             onpropertychanged("check");         }     }     public string name     {         => _name;         set         {             if (_name == value) return;             _name = value;             onpropertychanged("name");         }     }     public int firstday     {         => _firstday;         set         {             if (_firstday == value) return;             _firstday = value;             onpropertychanged("firstday")         }     }     public int lastday     {         => _lastday;         set         {             if (_lastday == value) return;             _lastday = value;             onpropertychanged("lastday");         }     } } public class propertychangedbase : inotifypropertychanged {     public event propertychangedeventhandler propertychanged;     protected void onpropertychanged(string propertyname)     {         propertychanged?.invoke(this, new propertychangedeventargs(propertyname));     } } 

use below binding second list

itemssource="{binding selectedcycles}" 

and in view model

public ienumerable<cycles> selectedcycles  {   { return mydata.where(x => x.check== true); }  }