What s the difference between the Window Loaded and Window ContentRendered events

Question

What s the difference between the Window Loaded and Window ContentRendered events in WPF   Is the ContentRendered event called first    The description of the Window ContentRendered event here just says     Occurs after a window s content has been rendered    The description of the Window Loaded event here says     Occurs when the element is laid out  rendered  and ready for interaction     I have a case where I want to set the window s MaxHeight to the height of the working area of the screen that is displaying my window   Which event should I do it in   Edit   I think I found what I was looking for  but I m even more confused now   The Loaded event happens first and then the ContentRendered event happens   In the book Programming WPF by Chris Sells  amp  Ian Griffiths  it says that the Loaded event is      Raised just before the window is shown   While the  ContentRendered  event is      Raised when the window s content is visually rendered    This contradicts what the MSDN documentation says about the Loaded event      Occurs when the element is laid out  rendered  and ready for interaction     This is even more confusing now

User · Answer

If you re using data binding  then you need to use the ContentRendered event   For the code below  the Header is NULL when the Loaded event is raised  However  Header gets its value when the ContentRendered event is raised    lt MenuItem Header   Binding NewGame Name   Command   Binding NewGameCommand     gt

User · Answer

This is not about the difference between Window ContentRendered and Window Loaded but about what how the Window Loaded event can be used   I use it to avoid splash screens in all applications which need a long time to come up          initializing my main window     public MyAppMainWindow                 InitializeComponent                Set the event         this ContentRendered    MyAppMainWindow ContentRendered             private void MyAppMainWindow ContentRendered object sender  EventArgs e                       comes up quick when the controls are loaded and rendered             unset the event         this ContentRendered -  MyAppMainWindow ContentRendered                  make the time comsuming init stuff here

User · Answer

I think there is little difference between the two events  To understand this  I created a simple example to manipulation   XAML   lt Window x Class  LoadedAndContentRendered MainWindow          xmlns  http   schemas microsoft com winfx 2006 xaml presentation          xmlns x  http   schemas microsoft com winfx 2006 xaml          Name  MyWindow          Title  MainWindow  Height  1000  Width  525          WindowStartupLocation  CenterScreen          ContentRendered  Window ContentRendered               Loaded  Window Loaded  gt        lt Grid Name  RootGrid  gt               lt  Grid gt   lt  Window gt    Code behind  private void Window ContentRendered object sender  EventArgs e        MessageBox Show  ContentRendered       private void Window Loaded object sender  RoutedEventArgs e        MessageBox Show  Loaded           In this case the message Loaded appears the first after the message ContentRendered  This confirms the information in the documentation   In general  in WPF the Loaded event fires if the element      is laid out  rendered  and ready for interaction    Since in WPF the Window is the same element  but it should be generally content that is arranged in a root panel  for example  Grid   Therefore  to monitor the content of the Window and created an ContentRendered event  Remarks from MSDN      If the window has no content  this event is not raised    That is  if we create a Window    lt Window x Class  LoadedAndContentRendered MainWindow      xmlns  http   schemas microsoft com winfx 2006 xaml presentation      xmlns x  http   schemas microsoft com winfx 2006 xaml      Name  MyWindow              ContentRendered  Window ContentRendered       Loaded  Window Loaded    gt    It will only works Loaded event    With regard to access to the elements in the Window  they work the same way  Let s create a Label in the main Grid of Window   In both cases we have successfully received access to Width   private void Window ContentRendered object sender  EventArgs e        MessageBox Show  ContentRendered      SampleLabel Width ToString        private void Window Loaded object sender  RoutedEventArgs e        MessageBox Show  Loaded      SampleLabel Width ToString            As for the Styles and Templates  at this stage they are successfully applied  and in these events we will be able to access them      For example  we want to add a Button   private void Window ContentRendered object sender  EventArgs e        MessageBox Show  ContentRendered      SampleLabel Width ToString          Button b1   new Button        b1 Content    ContentRendered Button       RootGrid Children Add b1       b1 Height   25      b1 Width   200      b1 HorizontalAlignment   HorizontalAlignment Right     private void Window Loaded object sender  RoutedEventArgs e        MessageBox Show  Loaded      SampleLabel Width ToString          Button b1   new Button        b1 Content    Loaded Button       RootGrid Children Add b1       b1 Height   25      b1 Width   200      b1 HorizontalAlignment   HorizontalAlignment Left      In the case of Loaded event  Button to add to Grid immediately at the appearance of the Window  In the case of ContentRendered event  Button to add to Grid after all its content will appear    Therefore  if you want to add items or changes before load Window you must use the Loaded event  If you want to do the operations associated with the content of Window such as taking screenshots you will need to use an event ContentRendered

User · Answer

If you visit this link https   msdn microsoft com library ms748948 28v vs 100 29 aspx Window Lifetime Events and scroll down to Window Lifetime Events it will show you the event order   Open    SourceInitiated Activated Loaded ContentRendered   Close    Closing Deactivated Closed

[wpf] What's the difference between the Window.Loaded and Window.ContentRendered events

Examples related to wpf

Examples related to events

Examples related to window