c# - mysterious runtime error in applying a template to wpf window -

i have hard problem dealing template. please me.

app.xaml

<application x:class="wpfapplication1.app"              xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"              xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml">  //note didn't set startupuri in application tag please.      <application.resources>          <style targettype="window" x:key="mywindowstyle">             <setter property="template">                 <setter.value>                     <controltemplate>                         <grid>                             <rectangle fill="gray" radiusx="30" radiusy="30"/>                             <contentpresenter/>                         </grid>                     </controltemplate>                 </setter.value>             </setter>         </style>      </application.resources> </application> 

app.xaml.cs

using system; using system.windows;  namespace wpfapplication1 {     public partial class app : application     {          cmainwindow winmain;          protected override void onstartup(startupeventargs e)         {             base.onstartup(e);              winmain = new cmainwindow();             winmain.showdialog();          }      } } 

cmainwindow.xaml

<window x:class="wpfapplication2.cmainwindow"         xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"         xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"         title="mainwindow" height="350" width="525" style="{staticresource mywindowstyle}" background="red"> </window> 

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question #1

when run program, ide occure runtime error : xmlparseexception. add line in app.xaml, runs properly. line : startupuri="cmainwindow.xaml".

what this? relationship between template , startupuri? please tell me this.

question #2

when add control cmainwindow, didn't apeear set in window's template.

how can add control in situation?

thanks.

question #1 wpf application centered around window. you're override of onstartup unnecessary. setting startupuri application automatically start displaying window.

there no actual relationship between template , startupuri. happen using app.xaml store global styles.

question #2

the magic field add "targettype" on control template. have explicitly window type.

<application x:class="simplewpf.app"              xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"              xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"              startupuri="mainwindow.xaml">     <application.resources>         <style targettype="window" x:key="mywindowstyle">             <setter property="template">                 <setter.value>                     <!-- explicitly setting targettype window -->                     <controltemplate targettype="window">                         <grid>                              <rectangle fill="gray" radiusx="30" radiusy="30"/>                               <contentpresenter/>                         </grid>                     </controltemplate>                 </setter.value>             </setter>         </style>     </application.resources> </application>