问题
I am both a freshman in WP7 and c# development .I confused with listbox removing operate. I want to remove a item through a click event(remove item data and refresh UI).I've searched in website,and knew first resource should extend ObservableCollection, but How to do next?Who can give me a more detail example. Here is my code MainPage.xaml.Example source download
<phone:PhoneApplicationPage x:Class="WPListBoxImage.MainPage"
xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
xmlns:phone="clr-namespace:Microsoft.Phone.Controls;assembly=Microsoft.Phone"
xmlns:shell="clr-namespace:Microsoft.Phone.Shell;assembly=Microsoft.Phone"
xmlns:d="http://schemas.microsoft.com/expression/blend/2008"
xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"
xmlns:data="clr-namespace:WPListBoxImage"
mc:Ignorable="d"
d:DesignWidth="480"
d:DesignHeight="768"
FontFamily="{StaticResource PhoneFontFamilyNormal}"
FontSize="{StaticResource PhoneFontSizeNormal}"
Foreground="{StaticResource PhoneForegroundBrush}"
SupportedOrientations="Portrait"
Orientation="Portrait"
shell:SystemTray.IsVisible="True">
<phone:PhoneApplicationPage.Resources>
<data:Products x:Key="productCollection" />
<data:PriceConverter x:Key="priceConvert" />
</phone:PhoneApplicationPage.Resources>
<!--LayoutRoot is the root grid where all page content is placed-->
<Grid x:Name="LayoutRoot"
Background="Transparent">
<Grid.RowDefinitions>
<RowDefinition Height="Auto" />
<RowDefinition Height="*" />
</Grid.RowDefinitions>
<!--TitlePanel contains the name of the application and page title-->
<StackPanel x:Name="TitlePanel"
Grid.Row="0"
Margin="12,17,0,28">
<TextBlock x:Name="ApplicationTitle"
Text="PDSA"
Style="{StaticResource PhoneTextNormalStyle}" />
<TextBlock x:Name="PageTitle"
Text="Products"
Margin="9,-7,0,0"
Style="{StaticResource PhoneTextTitle1Style}" />
</StackPanel>
<!--ContentPanel - place additional content here-->
<Grid x:Name="ContentPanel"
Grid.Row="1"
Margin="12,0,12,0">
<ListBox x:Name="lstData"
ItemsSource="{Binding Source={StaticResource productCollection}, Path=DataCollection}" SelectionChanged="lstData_SelectionChanged">
<ListBox.ItemTemplate>
<DataTemplate>
<StackPanel Orientation="Horizontal">
<Image Margin="8"
VerticalAlignment="Top"
Source="{Binding Path=ImageUri}"
Width="100"
Height="100" />
<StackPanel>
<TextBlock Margin="8"
Width="250"
TextWrapping="Wrap"
VerticalAlignment="Top"
HorizontalAlignment="Left"
Text="{Binding Path=ProductName}" />
<TextBlock Width="100"
Margin="8,0,8,8"
VerticalAlignment="Top"
HorizontalAlignment="Left"
Text="{Binding Path=Price, Converter={StaticResource priceConvert}}" />
</StackPanel>
</StackPanel>
</DataTemplate>
</ListBox.ItemTemplate>
</ListBox>
</Grid>
</Grid>
</phone:PhoneApplicationPage>
MainPage.xaml.cs
using System;
using System.Collections.Generic;
using System.Linq;
using System.Net;
using System.Windows;
using System.Windows.Controls;
using System.Windows.Documents;
using System.Windows.Input;
using System.Windows.Media;
using System.Windows.Media.Animation;
using System.Windows.Shapes;
using Microsoft.Phone.Controls;
namespace WPListBoxImage
{
public partial class MainPage : PhoneApplicationPage
{
// Constructor
public MainPage()
{
InitializeComponent();
}
private void lstData_SelectionChanged(object sender, SelectionChangedEventArgs e)
{
ListBoxItem lbi = ((sender as ListBox).SelectedItem as ListBoxItem);
//delete a item,what should to do next?
}
}
}
Products.cs
using System;
using System.Collections.Generic;
using System.Collections.ObjectModel;
using System.Linq;
namespace WPListBoxImage
{
//a ObservableCollection<T>,
public class Products : ObservableCollection<Product>
{
public Products()
{
DataCollection = new ObservableCollection<Product>();
BuildCollection();
}
private const string IMG_PATH = "../Images/";
public ObservableCollection<Product> DataCollection { get; set; }
public ObservableCollection<Product> BuildCollection()
{
//DataCollection = new ObservableCollection<Product>();
DataCollection.Add(new Product("Haystack Code Generator for .NET", 799, IMG_PATH + "Haystack.jpg"));
DataCollection.Add(new Product("Fundamentals of N-Tier eBook", Convert.ToDecimal(19.95), IMG_PATH + "FundNTier_100.jpg"));
DataCollection.Add(new Product("Fundamentals of ASP.NET Security eBook", Convert.ToDecimal(19.95), IMG_PATH + "FundSecurity_100.jpg"));
DataCollection.Add(new Product("Fundamentals of SQL Server eBook", Convert.ToDecimal(19.95), IMG_PATH + "FundSQL_100.jpg"));
DataCollection.Add(new Product("Fundamentals of VB.NET eBook", Convert.ToDecimal(19.95), IMG_PATH + "FundVBNet_100.jpg"));
DataCollection.Add(new Product("Fundamentals of .NET eBook", Convert.ToDecimal(19.95), IMG_PATH + "FundDotNet_100.jpg"));
DataCollection.Add(new Product("Architecting ASP.NET eBook", Convert.ToDecimal(19.95), IMG_PATH + "ArchASPNET_100.jpg"));
DataCollection.Add(new Product("PDSA .NET Productivity Framework", Convert.ToDecimal(2500), IMG_PATH + "framework.jpg"));
return DataCollection;
}
}
}
Product.cs
using System;
namespace WPListBoxImage
{
public class Product
{
#region Constructors
public Product()
{
}
public Product(string name, decimal price, string imageUri)
{
this.ProductName = name;
this.Price = price;
this.ImageUri = imageUri;
}
#endregion
public string ProductName { get; set; }
public decimal Price { get; set; }
public string ImageUri { get; set; }
}
}
Here is app screenshot.
thank's for your patience.
回答1:
Your Products class shouldn't inherit anything.
public class Products
Accessing all the items in your collection is done through the DataCollection property of the Product class. For example,
Products myProducts = new Products();
ObservableCollection<Product> myData = myProducts.DataCollection;
It also depends on how you want to use Products. You may be able to totally do away with this class and then do something like:
ObservableCollection<Product> Products = new ObservableCollection<Product>();
Products.Add(new Product("Haystack Code Generator for .NET", 799, IMG_PATH + "Haystack.jpg"));
// etc...
回答2:
Firstly you need to obtain a reference to your product collection:
Products productCollection = this.Resources["productCollection"] as Products;
Then find the item that was clicked, this will be the DataContext of the ListBoxItem:
ListBoxItem lbi = ((sender as ListBox).SelectedItem as ListBoxItem);
Product product = lbi.DataContext as Product;
(although, I think that as your listbox is databound, the SelectedItem should be a Product instance. You can check this yourself in the debugger)
Then simply remove it, the ObservableCollection will ensure that the UI is updated:
productCollection.Remove(product);
来源：https://stackoverflow.com/questions/9662479/remove-an-item-from-listbox-in-wp7