data binding - databinding combobox in Dataform Silverlight using MVVM in Update -

i have master/detail – datagrid/dataform , after select item shows in dataform update, have problem databinding or populating combox departments , set selectedemployee.departmentid selectedvalue.

here 2 questions now:

1. in employeeviewmodel code doesn’t work , question why?

  private observablecollection<department> _departments;         public observablecollection<department> departments         {             { return _departments; }             set             {                 _departments = value;                 raisepropertychanged("departments");             }         } 

but code works fine

   private observablecollection<department> _departments;         public observablecollection<department> departments         {             {                  if (_departments == null)                 {                     _departments = new observablecollection<department> {                         new department()                         { id = 1, departmentname = "technical " + 1, },                         new department()                         { id = 2,  departmentname = "technical " + 2, },                         new department()                         { id = 3,  departmentname = "technical " + 3, }                                         };                 }                   return _departments;              }             set             {                 _departments = value;                 raisepropertychanged("departments");             }         } 

2. behavior of combobox inside , outside dataform different. outside works, inside doesn’t. think here need use source in itemssource, don’t know how. there question how fix it?

employeeview.xaml

<navigation:page    xmlns:local="clr-namespace:departmenttechmanager"             x:class="departmenttechmanager.views.employeeview"                     xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"                     xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"                     xmlns:d="http://schemas.microsoft.com/expression/blend/2008"                    xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"                    mc:ignorable="d"                    xmlns:navigation="clr-namespace:system.windows.controls;assembly=system.windows.controls.navigation"                    d:designwidth="820" d:designheight="780"                    title="employees"                    style="{staticresource pagestyle}"              xmlns:sdk="http://schemas.microsoft.com/winfx/2006/xaml/presentation/sdk"              xmlns:i="http://schemas.microsoft.com/expression/2010/interactivity"              xmlns:mvvmlightcmd="clr-namespace:galasoft.mvvmlight.command;assembly=galasoft.mvvmlight.extras.sl4"             xmlns:data="clr-namespace:system.windows.controls;assembly=system.windows.controls.data"             xmlns:dataformtoolkit="clr-namespace:system.windows.controls;assembly=system.windows.controls.data.dataform.toolkit"               datacontext="{binding employeestatic, source={staticresource locator}}">  <data:datagrid grid.row="0" x:name="dgemployees" canusersortcolumns="true"                                              isreadonly="true" autogeneratecolumns="true"                                              itemssource="{binding employees}"                                              selecteditem="{binding selectedemployee, mode=twoway}"  margin="0,36,-123,0"></data:datagrid> <dataformtoolkit:dataform x:name="dfdetails"       currentitem="{binding selectedemployee}" autogeneratefields="false"       commitbuttoncontent="save" commandbuttonsvisibility="edit, commit, cancel">       <dataformtoolkit:dataform.edittemplate>                       <datatemplate>                         <stackpanel>                            <dataformtoolkit:datafield label="name">     <textbox text="{binding name, mode=twoway}" /></dataformtoolkit:datafield>        <dataformtoolkit:datafield label="departments">               <combobox itemssource="{binding departments}"           displaymemberpath="departmentname"             selectedvaluepath="id"               selectedvalue="{binding path=selectedemployee.departmentid, mode=twoway}" />        </dataformtoolkit:datafield>       </stackpanel>      </datatemplate>             </dataformtoolkit:dataform.edittemplate>             <i:interaction.triggers><i:eventtrigger eventname="editended">                 <mvvmlightcmd:eventtocommand command="{binding saveemployeescommand}"/>                </i:eventtrigger></i:interaction.triggers>             </dataformtoolkit:dataform> 

in viewmodellocator.cs:

 public viewmodellocator()         {              _sp = serviceproviderbase.instance;              createdepartment();              createemployee();          }  #region employeeviewmodel private static employeeviewmodel _employee;  public static employeeviewmodel employeestatic {         {         if (_employee == null)         {             createemployee();         }          return _employee;     } }  [system.diagnostics.codeanalysis.suppressmessage("microsoft.performance",     "ca1822:markmembersasstatic",     justification = "this non-static member needed data binding purposes.")] public employeeviewmodel employee {         {         return employeestatic;     } }  public static void clearemployee() {     //do later     //_employee.cleanup();     _employee = null; }  public static void createemployee() {     if (_employee == null)     {         _employee = new employeeviewmodel(_sp.pageconductor, _sp.employeedataservice);     } } #endregion  #region departmentviewmodel         private static departmentviewmodel _department;          public static departmentviewmodel departmentstatic         {                         {                 if (_department == null)                 {                     createdepartment();                 }                  return _department;             }         }          [system.diagnostics.codeanalysis.suppressmessage("microsoft.performance",             "ca1822:markmembersasstatic",             justification = "this non-static member needed data binding purposes.")]         public departmentviewmodel department         {                         {                 return departmentstatic;             }         }          public static void cleardepartment()         {             //do later             //_department.cleanup();             _department = null;         }          public static void createdepartment()         {             if (_department == null)             {                 _department = new departmentviewmodel(_sp.pageconductor, _sp.departmentdataservice);             }         }          #endregion 

can me?

combox empty. can populate departments so:

departmenttechmanagerdomainservice.metadata.cs

 [metadatatypeattribute(typeof(employee.employeemetadata))]         public partial class employee         {      [include]      public department department { get; set; }      public nullable<int> departmentid { get; set; }      public string name { get; set; }         }  

departmenttechmanagerdomainservice.cs

public iqueryable<employee> getemployees()         {return this.objectcontext.employees.include("department").orderby(e=>e.name);} 

here viewmodel code:

        private observablecollection<department> _departments;         public observablecollection<department> departments         {             { return _departments; }             set             {                 _departments = value;                 raisepropertychanged("departments");             }         }          private department _selecteddepartment;         public department selecteddepartment         {             { return _selecteddepartment; }             set             {                 _selecteddepartment = value;                 raisepropertychanged("selecteddepartment");             }         }  private void initializemodels()         {             employees = new observablecollection<employee>();             selectedemployee = new employee();             newemployee = new employee();              //new             departments = new observablecollection<department>();             selecteddepartment = new department();          }  private void getemployeescallback(ienumerable<employee> employees)         {             if (employees != null)             {                 foreach (var employee in employees)                 {                     employees.add(employee);                     //new                     if (!departments.contains(employee.department))                         departments.add(employee.department);                  }                 if (employees.count > 0)                 {                     selectedemployee = employees[0];                 }              }         } 

i make departments distinct, here departments have been selected, here aren't haven't been selected yet, , still combobox not populated departments in dataform. ?!

2nd question - looks combobox inside , outside of dataform receives different datacontext , hence trying locate departments properties on different sources. not clear how fix since haven't shown of viewmodels.

pay attention vs output window, provides detailed info regarding binding errors , i'm assuming there binding errors in case.

try modifying department related bindings in following way:

<combobox itemssource="{binding datacontext.departments, relativesoruce={relativesource ancestortype={x:type localviews:employeeview}}}" /> 

where localviews should xml-namespace departmenttechmanager.views. try same trick selecteditem binding.