wpf - 如何从代码隐藏访问 ListBox 动态创建项的属性？

Question

XAML:

<Window x:Class="WpfApp_ListBoxTest.Window1"
    xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
    xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
    Title="Window1" Height="300" Width="300">
    <Grid>
  <ListBox Name="lb" Margin="0,0,0,70"></ListBox>
  <Button Height="23" HorizontalAlignment="Left" Margin="12,0,0,41" Name="btnAdd" VerticalAlignment="Bottom" Content="Add item" Width="75" Click="btnAdd_Click"></Button>
  <TextBox Height="23" Margin="93,0,12,41" Name="txtInput" VerticalAlignment="Bottom" />
  <Button Height="23" HorizontalAlignment="Left" Margin="12,0,0,12" Name="btnGet" VerticalAlignment="Bottom" Content="Get value" Width="75" Click="btnGet_Click"></Button>
  <TextBox Height="23" Margin="93,0,12,12" Name="txtReturn" VerticalAlignment="Bottom" IsReadOnly="True" />
 </Grid>
</Window>

夏普:

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
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 System.Xml;

namespace WpfApp_ListBoxTest
{
 /// <summary>
 /// Interaction logic for Window1.xaml
 /// </summary>
 public partial class Window1 : Window
 {
  public Window1()
  {
   InitializeComponent();
  }

  private void btnAdd_Click(object sender, RoutedEventArgs e)
  {
   TextBox txt = new TextBox();
   txt.Width = 200;
   txt.Text = txtInput.Text;
   lb.Items.Add(txt);
  }

  private void btnGet_Click(object sender, RoutedEventArgs e)
  {
   // What do I need to write here to get the value of the Text property of the selected TextBox?

  }
 }
}

和截图:(对不起，我不允许直接发布图片) http://i825.photobucket.com/albums/zz180/mGlushed/get_listbox_item_property.png

(在上图中，我想在单击“获取值”按钮时获取值“b”。)

我想知道是否有一种简单的方法可以实现这一点。

我是 WPF 的新手，所以我只知道从头开始做这件事，即:创建一个数组。每次创建新的 TextBox 时，将其添加到数组中。然后通过数组访问文本框。但我认为这听起来不是很理想。

Answer 1

做你想做的事情的“WPF 方式”是使用数据绑定(bind):

1. 使用名为 Text 的字符串属性定义一个类。
2. 创建该类的集合。
3. 将您的列表框 ItemsSource 绑定(bind)到集合。
4. 创建一个显示 TextBox 的 DataTemplate，其 Text 属性使用 {Binding Path=Text} 绑定(bind)。
5. 在 btnAdd_Click 中添加一个项目到集合中(不是直接添加到 ListBox 中)
6. 在 btnGet_Click 中，您可以通过将 ListBox.SelectedItem 转换为您的类并获取其 Text 属性来获取输入的文本。

例子:

简单类:

public class VMObject
{
    public VMObject(string text)
    {
        Text = text;
    }

    public string Text { get; set; }
}

窗口代码隐藏:

public partial class Window1 : Window
{
    public ObservableCollection<VMObject> VM { get; set; }

    public Window1()
    {
        VM = new ObservableCollection<VMObject>();
        InitializeComponent();
    }

    private void btnAdd_Click(object sender, RoutedEventArgs e)
    {
        VM.Add(new VMObject(txtInput.Text));
    }

    private void btnGet_Click(object sender, RoutedEventArgs e)
    {
        if (lb.SelectedItem == null)
            MessageBox.Show("No item is selected!");
        txtReturn.Text = ((VMObject)lb.SelectedItem).Text;
    }
}

XAML:

<Window x:Class="lbtest.Window1"
    xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
    xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
    Name="Window"
    Title="Window1" Height="300" Width="300">
    <Window.Resources>
        <DataTemplate x:Key="TextBoxTemplate">
            <TextBox Text="{Binding Path=Text}"/>
        </DataTemplate>
    </Window.Resources>
    <Grid>
        <ListBox Name="lb" Margin="0,0,0,70"
                 ItemsSource="{Binding ElementName=Window, Path=VM}"
                 ItemTemplate="{StaticResource TextBoxTemplate}" />
        <Button Height="23" HorizontalAlignment="Left" Margin="12,0,0,41"
                Name="btnAdd" VerticalAlignment="Bottom"
                Content="Add item" Width="75" Click="btnAdd_Click" />
        <TextBox Height="23" Margin="93,0,12,41"
                 Name="txtInput" VerticalAlignment="Bottom" />
        <Button Height="23" HorizontalAlignment="Left" Margin="12,0,0,12"
                Name="btnGet" VerticalAlignment="Bottom"
                Content="Get value" Width="75" Click="btnGet_Click" />
        <TextBox Height="23" Margin="93,0,12,12"
                 Name="txtReturn" VerticalAlignment="Bottom" IsReadOnly="True" />
    </Grid>
</Window>