具有不同输出的WPF动态列表框

Question

At first I want to say that i searched on internet and I didn't found anything. I would like to make a dynamic song list, that when user adds a song, new object will be added with name and lenght and when he selects this song he would get a path to the selected song. Here is code to understand better:

XAML:

<Window x:Class="ListBox.MainWindow"
    xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
    xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
    Title="MainWindow" Height="350" Width="525">
<Grid>
    <ListBox x:Name="SongList" HorizontalAlignment="Left" Height="278" Margin="10,10,0,0" VerticalAlignment="Top" Width="248"/>
    <TextBlock HorizontalAlignment="Left" Margin="287,124,0,0" TextWrapping="Wrap" Text="Path" VerticalAlignment="Top" Width="194" Height="22"/>
    <Label Content="Song Path" HorizontalAlignment="Left" Margin="287,98,0,0" VerticalAlignment="Top" Width="194"/>
    <Button Content="Add Song" HorizontalAlignment="Left" Margin="10,293,0,0" VerticalAlignment="Top" Width="132" Click="Button_Click"/>

</Grid>

and code:

using Microsoft.Win32;
using System;
using System.Collections.Generic;
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;

namespace ListBox
{
    /// <summary>
    /// Interaction logic for MainWindow.xaml
    /// </summary>
    public partial class MainWindow : Window
    {
        public MainWindow()
        {
            InitializeComponent();
        }

        private void Button_Click(object sender, RoutedEventArgs e)
        {
            OpenFileDialog openfile = new OpenFileDialog();
            openfile.DefaultExt = ".mp3";
            openfile.Filter = "mp3 | *.mp3";
            Nullable<bool> result = openfile.ShowDialog();
            if (result == true)
            {
                String file = openfile.FileName;
                FileInfo fileinfo = new FileInfo(file);

                SongList.Items.Add(fileinfo.Name);
            }
        }
    }
}

so where the "Path" text box is I would like to get current selected song path. Is it possible to make with ItemBox or I need to make array that will save all paths?

Answer 1

at first you might want to have a look at MVVM programming. The concept is not that easy to understand, even harder to apply but once you got it you will be able to create good UI in no-time and it's especially perfect for what you are trying to do.

Now to your problem. FileInfo.Name only stores the file name not the path, so if you don't store the path separately, you won't be able to get it back from just the file name.

KillaKem's solution seems pretty good, however I wouldn't recommend using the Tag property for this. Just create a Collections::Generic::List (please, don't use arrays) class member to store the paths and then use the selectedIndexChange Event to update the PathSearchBox.

using MVVM you could just link the ListBox to a Dictionary which stores both, path and filename and just display the Filename, feel free to research MVVM a bit yourself.

Regards, Xaser

Answer 2

I think you should use for your songs, because you're writing a WPF application, an ObservableCollection of your song objects, in order to have a proper ListBox with your updated objects.

Then, you have to create a proper Song class with its own properties, like the SongName or the SongPath . In this class, you will implement the INotifyPropertyChanged interface and, for each property, you will raise an appropriate OnPropertyChanged event.

With this implementation, once you load a song and add it to the songs list, your ListBox will show the updated collection accordingly.

Further info about the ObservableCollection here .

If you want to have a look at a code sample, in this answer I written an example of developing an ObservableCollection.

Answer 3

You could try something along the lines of this,

XAML:

<Window x:Class="ListBox.MainWindow"
    xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
    xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
    Title="MainWindow" Height="350" Width="525">
<Grid>
    <ListBox x:Name="SongList" HorizontalAlignment="Left" Height="278" Margin="10,10,0,0" VerticalAlignment="Top" Width="248"/>
    <TextBlock HorizontalAlignment="Left" Margin="287,124,0,0" TextWrapping="Wrap" Text="Path" VerticalAlignment="Top" Width="194" Height="22"/>
    <Label Name ="pathLabel" Content="Song Path" HorizontalAlignment="Left" Margin="287,98,0,0" VerticalAlignment="Top" Width="194"/>
    <Button Content="Add Song" HorizontalAlignment="Left" Margin="10,293,0,0" VerticalAlignment="Top" Width="132" Click="Button_Click"/>

</Grid>

Back Code:

namespace ListBox
{
    /// <summary>
    /// Interaction logic for MainWindow.xaml
    /// </summary>
    public partial class MainWindow : Window
    {
        public MainWindow()
        {
            InitializeComponent();
        }

        private void Button_Click(object sender, RoutedEventArgs e)
        {
            OpenFileDialog openfile = new OpenFileDialog();
            openfile.DefaultExt = ".mp3";
            openfile.Filter = "mp3 | *.mp3";
            Nullable<bool> result = openfile.ShowDialog();
            if (result == true)
            {
                String file = openfile.FileName;
                FileInfo fileinfo = new FileInfo(file);

                SongList.Items.Add(fileinfo.Name);

                var pathList = SongList.Tag as List<string>;
                pathList.Add(fileinfo.DirectoryName);
                SongList.Tag = pathList;
            }
        }

         private void Selection_Changed(object sender, EventArgs e)
        {
              var myListBox = sender as ListBox;
              var myPathList = myListBox.Tag as List<string>;
              var filePath = myPathList[myListBox.SelectedIndex];

              pathLabel.Content = filePath;
        }
    }
}

Haven't tested the code but it should be working or close to working.

Answer 4

These is a SelectionChanged event in the listbox you can use. But i would recommend using bi