<Application x:Class="StyleSelector.App"
xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
StartupUri="MainWindow.xaml">
<Application.Resources>
<ResourceDictionary Source="BureauBlack.xaml"></ResourceDictionary>
</Application.Resources>
</Application>Results:Without style
With:
(there is some problem with the Style, it doesn't set the Window background color)
Setting style in code Now let's try to set the style of a window in code. Here is a method which takes in a XAML file name (containing styles and added to project). We create a new ResourceDictionary object and set it to the Window's Resource collection.private void SetStyle(string xamlFileName) { //clear the resources this.Resources.Clear(); if (!string.IsNullOrEmpty(xamlFileName)) { //load new resources ResourceDictionary resDict = new ResourceDictionary(); resDict.Source = new Uri(xamlFileName, UriKind.Relative); //merge the resources to preserve any other resource you may have added this.Resources.MergedDictionaries.Add(resDict);//or to overwrite and avoid memory leak you could also do this//this.Resources = resDict;} }We can use this method in the "Set Style to:" Combo Box selection changed event.
In one of projects I am working on, we have a requirement of showing ‘recent files’ used by the application. The files used by the application are XML files – no custom extension.
Our goal is:
For this task we need the following things:
- a RecentFiles class:
- should contain the list of recent files
- should have methods to load/save the list to disk (persistence)
- should have methods to add a recent file used or delete a non-existing file
- a MenuItem (with children) to show the list
Here is the RecentFiles class:
public partial class RecentFiles
{
private ObservableCollection<string> filesField;
public ObservableCollection<string> Files
{
get
{
return this.filesField;
}
set
{
this.filesField = value;
}//members for persistence – Load, Save
//you can find the full class definition in attachments
}
In the Windows.cs, we have a view model WindowViewModel having a property named AppRecentFiles.
Code in WindowViewModel:
public RecentFiles AppRecentFiles { get; set; }
Code in Windows.cs:
this._mainWindowViewModel = new MainWindowViewModel();
this.DataContext = this._mainWindowViewModel;
Now the XAML part:
<MenuItem x:Name="mnuRecentFiles" Header="_Recent Files" ItemsSource="{Binding AppRecentFiles.Files}">
<MenuItem.Resources>
<Style TargetType="MenuItem">
<Setter Property="Command" Value="{Binding ElementName=mnuRecentFiles, Path=DataContext.RecentFileChosenCommand}" />
<Setter Property="CommandParameter" Value="{Binding}" />
</Style>
</MenuItem.Resources>
</MenuItem>
And you are done with the basic infrastructure.
Now all we have to do is:
- add an item to the AppRecentFiles.Files list whenever we load a new file (from the Load option in menu). Tip: add the new item at top of list so that it shows as first item on the menu.
- remove file from list if the user selects a file from 'recent files’ is not found, perhaps after a confirmation message box
- load the recent files by using RecentFiles.LoadFromFile() method – usually done during Window load or app start
- and save (persist) the list by calling RecentFiles.SaveToFile() on App close or window close
