c# - TextBox binding is not working -

i have 2 usercontrols:

1) contactdetailsview.

2) searchbarview.

in thesearchbarview, have search button, raises command when clicked: command="{binding searchcommand}"

in searchbarview code behind, have following code: datacontext = new searchbarviewmodel();

in contactdetailsview have following code:

xmlns:viewmodel="clr-namespace:accounts_manager.usercontrols.searchbar" in definition of usercontrol , code underneath it:

<usercontrol.datacontext> <viewmodel:searchbarviewmodel /> </usercontrol.datacontext>

i have textbox following definition:

<textbox x:name="contactnametextbox" fontfamily="times new roman" foreground="darkred" horizontalalignment="stretch" horizontalcontentalignment="center" isenabled="false" grid.column="0" text="{binding contactid, mode=twoway, updatesourcetrigger=propertychanged}"/>

i have class called searchbarviewmodel following code:

    public string contactid     {         { return m_contactid; }         set         {             m_contactid = value;             onpropertychanged("contactid");         }     }     public icommand searchcommand     {         { return m_searchcommand ?? (m_searchcommand = new relaycommand(searchcontact)); }         set { m_searchcommand = value; }     }     public void searchcontact(object parameter)     {         currentcontact = dbhandler.search("עידן");          contactid = currentcontact.firstname + " " + currentcontact.lastname;         bankid = currentcontact.bankname;         accountnumber = currentcontact.accountnumber.tostring();     } 

the class defined this; searchbarviewmodel : viewmodelbase viewmodelbase inherits inotifypropertychanged , implements it.

relaycommand inherits icommand , implements it.

and now, after this, problem when click search button, expecting textbox updated, see being called , updated, property being raised, textbox not updated value of contactid.

any ideas?

simple, using 2 different objects!

datacontext = new searchbarviewmodel() in searchbarview sets datacontext button lives instance of searchbarviewmodel. no problem.

but

<usercontrol.datacontext>     <viewmodel:searchbarviewmodel /> </usercontrol.datacontext> 

in other view, also creates instance of object. thus, command invocation changes variable on its instance of view model, other instance doesn't see.

user controls (like search bar) don't have own data context, use dependency properties allow master vm have properties bound it. approach take in case. other way solve pass in common instance 1 or both of controls looking @ same object.