wpf - What is wrong with this DataGridComboBoxColumn binding syntax? -

i've found many answers question, can't seem syntax right. i've tried every logical combination can think of given explanation here , many others i've found has still eluded me after 3 weeks. need syntax of xaml right.

classes: (renamed simplicity/confidentiality)

usercontrol1 - contains 3 global lists, called streets, houses, , cars

street - contains 2 lists of associated houses , cars, called myhouses , mycars

house - presented in datagrid, 1 column being datagridcomboboxcolumn choose street house associated with. has street property called street declared in keep track of , other calculations in get/set.

car - presented in datagrid, 1 column being datagridcomboboxcolumn choose street car associated with. has street property called street declared in keep track of , other calculations in get/set.

if requested, can refactor code behind match above , post it.

xaml

<datagrid itemssource="{binding streets, mode=twoway}">     <datagrid.columns>         <datagridtextcolumn header="street"  binding="{binding streetid, mode=twoway}"/>     </datagrid.columns> </datagrid> <datagrid itemssource="{binding cars, mode=twoway}">     <datagrid.columns>         <datagridtextcolumn binding="{binding carid, mode=twoway}"/>         <datagridcomboboxcolumn          itemssource="{binding streets, relativesource={relativesource findancestor,ancestortype=usercontrol1}, mode=oneway}"         selecteditembinding="{binding street}"         selectedvalue="{binding streetid}"         selectedvaluepath="streetid"          displaymemberpath="streetid">             <datagridcomboboxcolumn.elementstyle>                 <style targettype="combobox">                     <setter property="itemssource" value="{binding streets, relativesource={relativesource findancestor,ancestortype=usercontrol1}, mode=oneway}"/>                     <setter property="isreadonly" value="true"/>                 </style>             </datagridcomboboxcolumn.elementstyle>             <datagridcomboboxcolumn.editingelementstyle>                 <style targettype="combobox">                     <setter property="itemssource" value="{binding streets, relativesource={relativesource findancestor,ancestortype=usercontrol1}, mode=oneway}"/>                 </style>             </datagridcomboboxcolumn.editingelementstyle>         </datagridcomboboxcolumn>     </datagrid.columns> </datagrid> <datagrid itemssource="{binding houses, mode=twoway}">     <!--copy of cars changed names--> </datagrid> 

if understand you're trying correctly, think you're after (based on mockup description):

note of variables have different names due mockup e.g. usercontrol.

<datagridcomboboxcolumn      selecteditembinding="{binding street}"     displaymemberpath="streetname">     <datagridcomboboxcolumn.elementstyle>         <style targettype="combobox">             <setter property="itemssource" value="{binding streets, relativesource={relativesource findancestor,ancestortype=usercontrol}, mode=oneway}"/>             <setter property="isreadonly" value="true"/>          </style>     </datagridcomboboxcolumn.elementstyle>     <datagridcomboboxcolumn.editingelementstyle>         <style targettype="combobox">             <setter property="itemssource" value="{binding streets, relativesource={relativesource findancestor,ancestortype=usercontrol}, mode=oneway}"/>         </style>      </datagridcomboboxcolumn.editingelementstyle>  </datagridcomboboxcolumn> 

for me, displays cars in datagrid, relevant columns, , selectable streets (you can adapt houses in similar way).

as think you've read, datagridcomboboxcolumn bit odd resolving datacontext. when you're trying set itemssource @ top of datagridcomboboxcolumn, it's causing confusion.

this should work example you've described (which i've modelled cars , houses having street object tracking property, rather id).

if decide want incorporate selectedvalue , use returned street id (to store id properties on car , house, think you'll have setter in style templates.

edit: mockup used (datacontext set self in xaml). n.b objects won't track each other (as wasn't sure set had).

public partial class usercontrol1 : usercontrol {     public list<street> streets { get; set; }     public list<house> houses { get; set; }     public list<car> cars { get; set; }      public usercontrol1()     {         streets = new list<street>();         houses = new list<house>();         cars = new list<car>();          street streetone = new street() { streetid = 1, name = "street one" };         street streettwo = new street() { streetid = 1, name = "street two" };         car carone = new car() { carid = 1, name = "kitt", mystreet = streetone };         car cartwo = new car() { carid = 2, name = "car 2", mystreet = streettwo };         house houseone = new house() { houseid = 1, name = "house 1", mystreet = streetone };          initializecomponent();          streetone.mycars.add(carone);         streetone.myhouses.add(houseone);         streettwo.mycars.add(cartwo);         cars.add(carone);         cars.add(cartwo);         houses.add(houseone);         streets.add(streetone);         streets.add(streettwo);      } }  public class car {     public int carid { get; set; }     public string name { get; set; }     private street _street;     public street mystreet     {         { return this._street; }         set { this._street = value; }     } }  public class house {     public int houseid { get; set; }     public string name { get; set; }     public street mystreet { get; set; } }  public class street {     public int streetid { get; set; }     public string name { get; set; }     public list<house> myhouses { get; set; }     public list<car> mycars { get; set; }      public street()     {         myhouses = new list<house>();         mycars = new list<car>();     } }