在WPF中，ListBox项没有刷新? [英] ListBox item doesn't get refresh in WPF?

问题描述

我有一个包含几个项目的列表框.双击每个项目时，用户将获得编辑项目(项目文本)的选项.现在，一旦我更新了商品，列表框中的商品就不会更新.

I have a listbox which has couple of items. When double clicked on each item, the user get option to edit item (text of item). Now once i update the item, my item in listbox doesn't get updated.

第一个窗口(具有列表框)在MainWindow.xaml文件中，第二个窗口在EditTaskView.xaml(一个用于编辑项目文本的文件)中.

The first window (one which has listbox) is in MainWindow.xaml file and second window is in EditTaskView.xaml(one which let's edit the items text) file.

显示列表中项目的代码为:

The code that displays items in lists is:

Main.Windows.cs

Main.Windows.cs

公共静态ObservableCollection TaskList；

public static ObservableCollection TaskList;

    public void GetTask()
    {
        TaskList = new ObservableCollection<Task>
                           {
                               new Task("Task1"),
                               new Task("Task2"),
                               new Task("Task3"),
                               new Task("Task4")
                           };

        lstBxTask.ItemsSource = TaskList;
    }

private void lstBxTask_MouseDoubleClick(对象发送者，MouseButtonEventArgs e) {

private void lstBxTask_MouseDoubleClick(object sender, MouseButtonEventArgs e) {

        var selectedTask = (Task)lstBxTask.SelectedItem;
        EditTask.txtBxEditedText.Text = selectedTask.Taskname;
        EditTask.PreviousTaskText = selectedTask.Taskname;  
        EditTask.Visibility = Visibility.Visible;
    } 

显示列表的xaml代码:

The xaml code that displays the list:

<ListBox x:Name="lstBxTask" Style="{StaticResource ListBoxItems}" MouseDoubleClick="lstBxTask_MouseDoubleClick">
        <ListBox.ItemTemplate>              
            <DataTemplate>                   
                <StackPanel>
                    <Rectangle Style="{StaticResource LineBetweenListBox}"/>
                    <StackPanel Orientation="Horizontal">
                        <TextBlock Text="{Binding Taskname}"  Style="{StaticResource TextInListBox}"/>
                        <Button Name="btnDelete" Style="{StaticResource DeleteButton}" Click="btnDelete_Click"/>                                                     
                    </StackPanel>
                </StackPanel>                   
            </DataTemplate>
        </ListBox.ItemTemplate>
    </ListBox> 
    <ToDoTask:EditTaskView x:Name="EditTask" Grid.Row="1" Grid.RowSpan="2" Grid.ColumnSpan="2" Visibility="Collapsed"/> 

TaskEditView.xaml中的保存"按钮可以执行以下操作:

The Save button in TaskEditView.xaml does this:

    public string PreviousTaskText { get; set; }

 private void btnSaveEditedText_Click(object sender, RoutedEventArgs e)
 {
            foreach (var t in MainWindow.TaskList)
            {
                if (t.Taskname == PreviousTaskText)
                {
                    t.Taskname = txtBxEditedText.Text;
                }
           }

            Visibility = Visibility.Collapsed;

 }

TaskList是ObservableCollection，即使更新了值，UI也会刷新.但这似乎不起作用.

TaskList is the ObservableCollection, and i though once you update the value the UI gets refreshed. But doesn't seem to work that way.

我想念什么?

推荐答案

看起来您可能需要在Task类中实现INotifyPropertyChanged.此界面会向UI发出警报，通知基础数据已更改，并且需要重新整理数据以更新视图.

Looks like you may need to implement INotifyPropertyChanged in your Task class. This interface alerts the UI that underlying data has changed and it needs to repull the data to update the view.

这篇关于在WPF中，ListBox项没有刷新?的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！