c# - WPF ObservableCollection not updating in view -

i working on project using mvvm user connects database server , presented list of database areas on server use. list of areas, using combobox has itemsource bound observablecollection.

combobox itemssource="{binding areacollecton}" selecteditem="{binding selectedarea}" 

in viewmodel, have observablecollection defined this:

private observablecollection<string> areacollection = new observablecollection<string>();  public observablecollection<string> areacollection {     { return areacollection; }     set{         areacollection = value;         onpropertychanged("areacollection");     } } 

the collection updated when server name entered , connect button clicked. click event poll server entered areas available , return list viewmodel.

public void connect() {     areacollection.clear();      serverconnection = new serverconnect();     arealist = serverconnection.getarealist(server);     //arealist defined dictionary<string, string>      foreach(keyvaluepair<string, string> area in arealist)     {         areacollection.add(area.key);     }     onpropertychanged("areacollection"); } 

i put break point @ foreach in connect method (invoked button click event) , stepped through saw areacollection being updated arealist expected. however, once completed building areacollection, nothing showing in combobox on view.

i new wpf , mvvm have feeling there small missing here. i've looked through of other posts here relating similar issues, , have implemented suggestions there still not updating view not sure missing. appreciated.

edit: i'm adding full xaml in case more helpful combobox line.

    <grid height="400" width="400" verticalalignment="center" horizontalalignment="center">     <grid.columndefinitions>         <columndefinition width="*" />         <columndefinition width="1.5*" />     </grid.columndefinitions>     <grid.rowdefinitions>         <rowdefinition height="50" />         <rowdefinition height="30" />         <rowdefinition height="30" />         <rowdefinition height="30" />         <rowdefinition height="30" />         <rowdefinition height="30" />         <rowdefinition height="30" />         <rowdefinition height="*" />     </grid.rowdefinitions>      <textblock grid.row="0" grid.columnspan="2" horizontalalignment="center" verticalalignment="center" x:name="lblprompt" textwrapping="wrap" text="enter laboratory login , connection info:" fontsize="18"  />      <label style="{staticresource connectlabel}" grid.row="1" grid.column="0" content="server:" />     <textbox style="{staticresource connecttextbox}" grid.row="1" grid.column="1" x:name="txtbxservername" textwrapping="wrap" tabindex="3" text="{binding server}" />      <button style="{staticresource connectbutton}" grid.row="2" grid.column="1" x:name="btnconnect" content="connect" fontsize="14">         <i:interaction.triggers>             <i:eventtrigger eventname="click">                 <ei:callmethodaction targetobject="{binding}" methodname="connect" />             </i:eventtrigger>         </i:interaction.triggers>     </button>      <label style="{staticresource connectlabel}" grid.row="3" grid.column="0" content="area:" />     <combobox style="{staticresource connectcombo}" grid.row="3" grid.column="1" x:name="txtbxareaname" tabindex="4" itemssource="{binding areacollecton}" selecteditem="{binding selectedarea}" >         <i:interaction.triggers>             <i:eventtrigger eventname="selectionchanged">                 <ei:callmethodaction targetobject="{binding}" methodname="areaconnect" />             </i:eventtrigger>         </i:interaction.triggers>     </combobox>      <label style="{staticresource connectlabel}" grid.row="4" grid.column="0" content="lab username:" />     <textbox style="{staticresource connecttextbox}" grid.row="4" grid.column="1" x:name="txtbxusername" textwrapping="wrap"  tabindex="1" text="{binding username}" />      <label style="{staticresource connectlabel}" grid.row="5" grid.column="0" content="lab password:" />     <passwordbox margin="2" grid.row="5" grid.column="1" x:name="pwdbxpassword" tabindex="5" passwordchanged="passwordbox_passwordchanged" />      <button style="{staticresource connectbutton}" grid.row="6" grid.column="1" x:name="btnlogin" content="login" fontsize="14">         <i:interaction.triggers>             <i:eventtrigger eventname="click">                 <ei:callmethodaction targetobject="{binding}" methodname="login" />             </i:eventtrigger>         </i:interaction.triggers>     </button>      <textblock grid.row="7" grid.columnspan="2" horizontalalignment="center" margin="10" textwrapping="wrap" fontsize="14" text="{binding status}" />  </grid> 

at first glance, see combox itemsource name different setting in code behind. shouldn't "areacollection" instead of "areacollecton". let me know if solves issue.