c# - Access textbox from ControlTemplate in UserControl.Resources -

i have control template defined this:

<usercontrol.resources>  <controltemplate targettype="{x:type datagrid}"  x:key="inputitemscontroltemplate">         <grid>             <grid.columndefinitions>                 <columndefinition width="120"/>                 <columndefinition width="200"/>                 <columndefinition width="20"/>                 <columndefinition width="200"/>             </grid.columndefinitions>             <grid grid.column="0">                 <grid.rowdefinitions>                     <rowdefinition height="25" />                     <rowdefinition height="25" />                     <rowdefinition height="25" />                 </grid.rowdefinitions>                 <label grid.row="1" content="{dynamicresource ucodestr}" horizontalalignment="left" verticalalignment="bottom" height="27" />                 <textbox name="txtucode" grid.row="2" height="23" horizontalalignment="left" verticalalignment="bottom"  width="100" text="{binding ucode, updatesourcetrigger=propertychanged}" />             </grid>             <grid grid.column="1">                 <grid.rowdefinitions>                     <rowdefinition height="25" />                     <rowdefinition height="25" />                     <rowdefinition height="25" />                     <rowdefinition height="25" />                     <rowdefinition height="25" />                 </grid.rowdefinitions>                 <label grid.row="1" content="{dynamicresource goodstr}" horizontalalignment="left" verticalalignment="bottom" height="27"/>                 <combobox grid.row="2" height="23" width="189" horizontalalignment="left"  name="cbgoods" itemssource="{binding path=goods}"  selecteditem="{binding path= good, updatesourcetrigger=propertychanged}" displaymemberpath="name" iseditable="true" istextsearchenabled="true" textsearch.textpath="name" />                 <label grid.row="3" content="{dynamicresource inputpricestr}" horizontalalignment="left" name="lblinputprice" verticalalignment="bottom" height="27"/>                 <textbox name="txtinputprice" grid.row="4" textalignment="right" height="23" width="189" horizontalalignment="left" verticalalignment="bottom" text="{binding path= inputprice, updatesourcetrigger=propertychanged,  validatesondataerrors=true, notifyonvalidationerror=true, stringformat='n2'}" />                                </grid>             <grid grid.column="3">                 <grid.rowdefinitions>                     <rowdefinition height="25" />                     <rowdefinition height="25" />                     <rowdefinition height="25" />                     <rowdefinition height="25" />                     <rowdefinition height="25" />                     <rowdefinition height="25" />                 </grid.rowdefinitions>                 <label grid.row="1" content="{dynamicresource ammountstr}" horizontalalignment="left" name="lblammount" verticalalignment="bottom" height="27"/>                 <textbox name="txtammount" textalignment="right"  grid.row="2" height="23" width="189" horizontalalignment="left" verticalalignment="bottom" text="{binding path=amount,  validatesondataerrors=true, notifyonvalidationerror=true,  updatesourcetrigger=propertychanged, stringformat='n2'}" />                                    <label grid.row="3" content="{dynamicresource suggestedpricestr}" horizontalalignment="left" name="lblsuggestedprice" verticalalignment="bottom" height="27"/>                 <textbox name="txtsuggestedprice" grid.row="4" textalignment="right" height="23" width="189" horizontalalignment="left" verticalalignment="bottom" text="{binding path= suggestedprice,  validatesondataerrors=true, notifyonvalidationerror=true, updatesourcetrigger=propertychanged, stringformat='n2'}" />                 <checkbox grid.row="5" name="cbhasvatdeduction"  ischecked="{binding path=hasvatdeduction}" />             </grid>         </grid>     </controltemplate> </usercontrol.resources> 

i implement template datagrid in codebehind. want access textbox "txtucode" , set focus it. tried this:

inputdocitemsdatagrid.template = (controltemplate)this.findresource("inputitemscontroltemplate");         textbox txtucode = (textbox)inputdocitemsdatagrid.template.findname("txtucode", inputdocitemsdatagrid);         txtucode.focus(); 

but txtucode allways null. how this?

principle, code good. when assigning template this:

inputdocitemsdatagrid.template = (controltemplate)this.findresource("inputitemscontroltemplate"); 

access elements available after control has loaded, i.e. when element laid out, rendered, , ready interaction.

so try example:

xaml

<window x:class="sampledatagrid.mainwindow"         xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"         xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"         title="mainwindow" height="350" width="525"         loaded="window_loaded"         contentrendered="window_contentrendered">      <window.resources>         <controltemplate x:key="inputitemscontroltemplate" targettype="{x:type datagrid}">             <grid>              ....                     </grid>        </controltemplate>     </window.resources>      <grid>         <datagrid name="inputdocitemsdatagrid" />     </grid> </window> 

code-behind

private void window_loaded(object sender, routedeventargs e) {     inputdocitemsdatagrid.template = (controltemplate)this.findresource("inputitemscontroltemplate"); }  private void window_contentrendered(object sender, eventargs e) {                 textbox txtucode = (textbox)inputdocitemsdatagrid.template.findname("txtucode", inputdocitemsdatagrid);     txtucode.focus(); } 

first, calls window_loaded event, window_contentrendered.

or this:

xaml

<grid>     <datagrid name="inputdocitemsdatagrid" loaded="inputdocitemsdatagrid_loaded" />      <button content="test" horizontalalignment="left" verticalalignment="bottom" click="button_click" /> </grid> 

code-behind

private void inputdocitemsdatagrid_loaded(object sender, routedeventargs e) {     inputdocitemsdatagrid.template = (controltemplate)this.findresource("inputitemscontroltemplate"); }  private void button_click(object sender, routedeventargs e) {     textbox txtucode = (textbox)inputdocitemsdatagrid.template.findname("txtucode", inputdocitemsdatagrid);     txtucode.focus(); }