Question

我创建了一个包含字典的列表框。

但我想删除项目列表框＆amp;点击一下字典。

代码：

的Xaml：

<ListBox x:Name="ListBoxPlayList" SelectionMode="Extended"/>

<Button x:Name="addbtn" Margin="2,5,41,5" Click="addbtn_Click" />

<Button x:Name="removebtn" Click="removebtn_Click" />

Xaml.cs：

public  Dictionary<string, string> fileDictionary = new Dictionary<string, string>();

private void addbtn_Click(object sender, RoutedEventArgs e)
        {
            var listCount = ListBoxPlayList.Items.Count;
            Microsoft.Win32.OpenFileDialog ofd = new Microsoft.Win32.OpenFileDialog();
            ofd.DefaultExt = ".mp3";
            ofd.Filter = "All|*.*";
            ofd.Multiselect = true;
            Nullable<bool> result = ofd.ShowDialog();
            if (result == true)
            {
                for (int i = 0; i < ofd.FileNames.Length; i++)
                {
                    var filePath = ofd.FileNames[i];
                    var fileName = System.IO.Path.GetFileName(filePath);
                    fileDictionary.Add(fileName, filePath);
                    ListBoxPlayList.Items.Add(fileName);
                }
                ListBoxPlayList.SelectedIndex = listCount;
            }
        }

我正在尝试使用此代码：

但是当我点击删除按钮时，项目从词典中移除但不从列表框中删除。

   private void remove(object sender, RoutedEventArgs e)
        {

            var itemsToRemove = listbox4.SelectedItems;
            foreach (var item in itemsToRemove)
            {
                fileDictionary.Remove(item.ToString());
                listbox4.Items.Remove(item);
            }

        }

注意：

我想从列表框中删除项目＆amp; fileDictionary立刻。

＆安培;没有播放项目。

当我不使用字典时，此代码有效。

private void removebtn_Click(object sender, RoutedEventArgs e)
    {
     object[] itemsToRemove = new object[ListBoxPlayList.SelectedItems.Count];
                ListBoxPlayList.SelectedItems.CopyTo(itemsToRemove, 0);

                foreach (object item in itemsToRemove)
                {
   if (mediaelement.Source != new Uri(item.ToString()))  //MediaPlayer source
   ListBoxPlayList.Items.Remove(item);

}

}

问题：

如何从列表框中删除所选项目＆amp;单击并忽略字典删除正在我的媒体元素上播放的项目？

Answer 1

请您查看此代码吗？没有得到整个代码，我无法测试它。

private void removebtn_Click(object sender, RoutedEventArgs e)
{
    object[] itemsToRemove = new object[ListBoxPlayList.SelectedItems.Count];
    ListBoxPlayList.SelectedItems.CopyTo(itemsToRemove, 0);
    foreach (var item in itemsToRemove)
    {
        fileDictionary.Remove(item.ToString());
        ListBoxPlayList.Items.Remove(item);
    }
}

Answer 2

你快到了。在熟悉基础知识之前，请始终使用括号。请阅读下面的评论。

private void removebtn_Click(object sender, RoutedEventArgs e)
{
     object[] itemsToRemove = new object[ListBoxPlayList.SelectedItems.Count];
     ListBoxPlayList.SelectedItems.CopyTo(itemsToRemove, 0);

     foreach (object item in itemsToRemove)
     {
         string filePath;
         fileDictionary.TryGetValue(item.ToString(), out filePath);
         if (mediaelement.Source != new Uri(filePath))  //MediaPlayer source
         {  //you forgot the parenthesis for the if condition.
            ListBoxPlayList.Items.Remove(item);//remove from list
            fileDictionary.Remove(item.ToString());//remove from dictionary
         }
     }
}

如何删除项目列表框＆amp;点击字典？

2 个答案: