public class ListBoxAutoScrollBehavior : Behavior<ListBox>
{
protected override void OnAttached()
{
AssociatedObject.SelectionChanged += AssociatedObject_SelectionChanged;
base.OnAttached();
}
private void AssociatedObject_SelectionChanged(object sender, SelectionChangedEventArgs e)
{
var lbx = sender as ListBox;
if (lbx != null && lbx.SelectedItem != null)
{
lbx.ScrollIntoView(lbx.SelectedItem);
}
}
protected override void OnDetaching()
{
AssociatedObject.SelectionChanged -= AssociatedObject_SelectionChanged;
base.OnDetaching();
}
}
<behavior:Interaction.Behaviors>
<local:ListBoxAutoScrollBehavior/>
</behavior:Interaction.Behaviors>
<ListBox.ContextMenu>
private void InitTimer()
{
System.Timers.Timer tmr = new System.Timers.Timer();
tmr.Interval = 1000;
tmr.Elapsed += Tmr_Elapsed;
tmr.Enabled = true;
}
private void Tmr_Elapsed(object sender, System.Timers.ElapsedEventArgs e)
{
if(++SelectedIdx>=booksCount)
{
SelectedIdx = 0;
}
SelectedBk = BooksCollection[SelectedIdx];
}
//xaml
<Window x:Class="WpfApp38.MainWindow"
xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
xmlns:d="http://schemas.microsoft.com/expression/blend/2008"
xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"
xmlns:behavior="http://schemas.microsoft.com/xaml/behaviors"
WindowState="Maximized"
xmlns:local="clr-namespace:WpfApp38"
mc:Ignorable="d"
Title="{Binding SelectedIdx,Mode=TwoWay,UpdateSourceTrigger=PropertyChanged}"
Height="450" Width="800">
<Window.Resources>
<Style TargetType="{x:Type TextBlock}" x:Key="tbkStyle">
<Setter Property="HorizontalAlignment" Value="Stretch"/>
<Setter Property="VerticalAlignment" Value="Center"/>
<Setter Property="FontSize" Value="30"/>
<Setter Property="Foreground" Value="Red"/>
<Style.Triggers>
<Trigger Property="IsMouseOver" Value="True">
<Setter Property="FontSize" Value="50"/>
<Setter Property="FontWeight" Value="ExtraBold"/>
</Trigger>
</Style.Triggers>
</Style>
</Window.Resources>
<Grid>
<ListBox ItemsSource="{Binding BooksCollection,Mode=TwoWay,UpdateSourceTrigger=PropertyChanged}"
SelectedIndex="{Binding SelectedIdx,Mode=TwoWay,UpdateSourceTrigger=PropertyChanged}"
SelectedItem="{Binding SelectedBk,Mode=TwoWay,UpdateSourceTrigger=PropertyChanged}"
VirtualizingPanel.IsContainerVirtualizable="True"
VirtualizingPanel.IsVirtualizing="True"
VirtualizingPanel.CacheLength="1"
VirtualizingPanel.CacheLengthUnit="Item"
>
<behavior:Interaction.Behaviors>
<local:ListBoxAutoScrollBehavior/>
</behavior:Interaction.Behaviors>
<ListBox.ContextMenu>
<ContextMenu>
<MenuItem Header="Export All"
Command="{Binding ExportAllCommand}"
CommandParameter="{Binding RelativeSource={RelativeSource Mode=FindAncestor,AncestorType={x:Type ContextMenu}},Path=PlacementTarget}"/>
<MenuItem Header="Mark All Selected"
Command="{Binding MarkAllSelected}"
CommandParameter="{Binding RelativeSource={RelativeSource Mode=FindAncestor,AncestorType={x:Type ContextMenu}},Path=PlacementTarget}"/>
</ContextMenu>
</ListBox.ContextMenu>
<ListBox.ItemTemplate>
<DataTemplate>
<StackPanel Orientation="Horizontal">
<CheckBox Content="IsSelected"
HorizontalAlignment="Stretch"
VerticalAlignment="Center"
FontSize="30"
IsChecked="{Binding ISSTEM}"
IsThreeState="False"/>
<TextBlock Text="{Binding Id}"
Style="{StaticResource tbkStyle}"/>
<TextBlock Text="{Binding ISBN}"
Style="{StaticResource tbkStyle}"
/>
<Border Width="500" Height="500"
BorderThickness="3"
BorderBrush="Black"
>
<Border.Background>
<ImageBrush ImageSource="{Binding ImgSource}"
RenderOptions.BitmapScalingMode="Fant"
RenderOptions.EdgeMode="Aliased"/>
</Border.Background>
</Border>
</StackPanel>
</DataTemplate>
</ListBox.ItemTemplate>
</ListBox>
</Grid>
</Window>
//cs
using System;
using System.Collections.Generic;
using System.Collections.ObjectModel;
using System.ComponentModel;
using System.Data.SqlTypes;
using System.IO;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using System.Windows;
using System.Windows.Controls;
using System.Windows.Data;
using System.Windows.Documents;
using System.Windows.Input;
using System.Windows.Media;
using System.Windows.Media.Imaging;
using System.Windows.Navigation;
using System.Windows.Shapes;
using Microsoft.Xaml.Behaviors;
using Newtonsoft.Json;
namespace WpfApp38
{
/// <summary>
/// Interaction logic for MainWindow.xaml
/// </summary>
public partial class MainWindow : Window
{
public MainWindow()
{
InitializeComponent();
var vm = new BookVM();
this.DataContext = vm;
}
}
public class BookVM : INotifyPropertyChanged
{
public BookVM()
{
InitData();
InitCommands();
}
private void InitTimer()
{
System.Timers.Timer tmr = new System.Timers.Timer();
tmr.Interval = 1000;
tmr.Elapsed += Tmr_Elapsed;
tmr.Enabled = true;
}
private void Tmr_Elapsed(object sender, System.Timers.ElapsedEventArgs e)
{
if(++SelectedIdx>=booksCount)
{
SelectedIdx = 0;
}
SelectedBk = BooksCollection[SelectedIdx];
}
private void InitCommands()
{
ExportAllCommand = new DelCommand(ExportAllCommandExecuted);
MarkAllSelected = new DelCommand(MarkAllSelectedExecuted);
}
private void MarkAllSelectedExecuted(object obj)
{
var books = ((System.Collections.IList)(obj as ListBox).ItemsSource)?.Cast<Book>()?.ToList();
if (books != null && books.Any())
{
booksCount = books.Count;
for (int i = 0; i < booksCount; i++)
{
books[i].ISSTEM = true;
}
MessageBox.Show("Mark all as Selected!");
}
}
private void ExportAllCommandExecuted(object obj)
{
var books = ((System.Collections.IList)(obj as ListBox))?.Cast<Book>()?.ToList();
if (books != null && books.Any())
{
string jsonStr = JsonConvert.SerializeObject(books, Formatting.Indented);
string jsonFile = $"{DateTime.Now.ToString("yyyyMMddHHmmssffff")}json.json";
File.WriteAllText(jsonFile, jsonStr);
MessageBox.Show($"Exported in {jsonFile}", "Export");
}
}
private void InitData()
{
var imgs = Directory.GetFiles(@"../../Images");
if (imgs != null && imgs.Any())
{
int imgsCount = imgs.Count();
BooksCollection = new ObservableCollection<Book>();
for (int i = 0; i < 100000; i++)
{
BooksCollection.Add(new Book()
{
Id = i + 1,
ISBN = $"ISBN_{i + 1}",
ISSTEM = (i % 5 == 0) ? true : false,
ImgSource = GetImgSourceViaUrl(imgs[i % imgsCount])
});
}
booksCount=BooksCollection.Count;
}
InitTimer();
}
private ImageSource GetImgSourceViaUrl(string url)
{
BitmapImage bmi = new BitmapImage();
bmi.BeginInit();
bmi.UriSource = new Uri(url, UriKind.RelativeOrAbsolute);
bmi.EndInit();
if (bmi.CanFreeze)
{
bmi.Freeze();
}
return bmi;
}
public event PropertyChangedEventHandler PropertyChanged;
private void OnPropertyChanged(string propertyName)
{
var handler = PropertyChanged;
if (handler != null)
{
handler?.Invoke(this, new PropertyChangedEventArgs(propertyName));
}
}
private ObservableCollection<Book> booksCollection;
public ObservableCollection<Book> BooksCollection
{
get
{
return booksCollection;
}
set
{
if (value != booksCollection)
{
booksCollection = value;
OnPropertyChanged(nameof(BooksCollection));
}
}
}
private int selectedIdx;
public int SelectedIdx
{
get
{
return selectedIdx;
}
set
{
if (value != selectedIdx)
{
selectedIdx = value;
OnPropertyChanged(nameof(SelectedIdx));
}
}
}
private Book selectedBk;
public Book SelectedBk
{
get
{
return selectedBk;
}
set
{
if(value!=selectedBk)
{
selectedBk = value;
OnPropertyChanged(nameof(SelectedBk));
}
}
}
private int booksCount { get; set; } = 0;
public DelCommand ExportAllCommand { get; set; }
public DelCommand MarkAllSelected { get; set; }
}
public class ListBoxAutoScrollBehavior : Behavior<ListBox>
{
protected override void OnAttached()
{
AssociatedObject.SelectionChanged += AssociatedObject_SelectionChanged;
base.OnAttached();
}
private void AssociatedObject_SelectionChanged(object sender, SelectionChangedEventArgs e)
{
var lbx = sender as ListBox;
if (lbx != null && lbx.SelectedItem != null)
{
lbx.ScrollIntoView(lbx.SelectedItem);
}
}
protected override void OnDetaching()
{
AssociatedObject.SelectionChanged -= AssociatedObject_SelectionChanged;
base.OnDetaching();
}
}
public class Book
{
public int Id { get; set; }
public bool ISSTEM { get; set; }
public string ISBN { get; set; }
public ImageSource ImgSource { get; set; }
}
public class DelCommand : ICommand
{
private Action<object> execute;
private Predicate<object> canExecute;
public DelCommand(Action<Object> executeValue, Predicate<object> canExecuteValue = null)
{
execute = executeValue;
canExecute = canExecuteValue;
}
public event EventHandler CanExecuteChanged
{
add
{
CommandManager.RequerySuggested += value;
}
remove
{
CommandManager.RequerySuggested -= value;
}
}
public bool CanExecute(object parameter)
{
if (canExecute == null)
{
return true;
}
return canExecute(parameter);
}
public void Execute(object parameter)
{
execute(parameter);
}
}
}
