Question

我有一些行，希望用户可以通过ctrl + a选择多个行，然后可以通过按键盘上的Delete键删除选定的项目。

我的代码不起作用。列表项可以通过ctrl + A进行选择，但是按Delete键后，仅一项将被删除。

private void lvTasks_KeyDown(object sender, KeyEventArgs e)
{
     if (e.KeyCode == Keys.A && e.Control)
    {
        lvTasks.MultiSelect = true;
        foreach (ListViewItem item in lvTasks.Items)
        {
            item.Selected = true;
        }
    }
    if (e.KeyCode == Keys.Delete) 
    foreach (ListViewItem eachItem in lvTasks.SelectedItems)
    {
         DeleteTask();
    }
}



public void DeleteTask()
{
    if (lvTasks.SelectedItems.Count > 0)
    {


            lvTasks.Items.Remove(lvTasks.SelectedItems[0]);
            Statics.SaveTasks(lvTasks.Items.Cast<ListViewItem>().Select(l => (Task)l.Tag).ToArray());
            UpdateTaskProgress(new Task());
            txtDownloadLink.Text = "";
            txtRarPassword.Text = "";
            txtReferenceLink.Text = "";
            chkBackupResource.Checked = Properties.Settings.Default.BackupSource;
            chkClearExtracted.Checked = Properties.Settings.Default.CleanExtract;
            chkRemoveRar.Checked = Properties.Settings.Default.RemoveRar;
            chkUseIDM.Checked = Properties.Settings.Default.UseIDM;
            chkRemoveDownload.Checked = Properties.Settings.Default.RemoveDownload;
            gbTaskProgress.SuspendLayout();
            settings = Statics.LoadSettings();
            gbTaskProgress.Controls.Clear();
            int max = Enum.GetValues(typeof(TaskProgresses)).Cast<int>().LastOrDefault();
            for (int i = 0; i <= max; i++)
                gbTaskProgress.Controls.Add(new TaskProgress(i + 1) { Left = 10, Top = (20 + 24 * i), Caption = ((TaskProgresses)i).ToString().CapitalSplit(), Task = new Task() });
            gbTaskProgress.ResumeLayout();
            lvTasks.Items.Clear();
            Statics.LoadTasks().ToList().ForEach(t =>
            {
                ListViewItem lvi = new ListViewItem(new string[] { (lvTasks.Items.Count + 1).ToString(), t.TaskName, $"{t.TaskId}", $"{t.Progress}-{t.Status}" });
                t.UI = this;
                if (t.Status == TaskStatuses.Active) t.Status = TaskStatuses.NotStarted;
                lvi.Tag = t;
                lvi.SubItems[0].Tag = t.Progress;
                lvTasks.Items.Add(lvi);
            });


        }

}

Answer 1

private void lvTasks_KeyDown(object sender, KeyEventArgs e)
{
    if (e.KeyCode == Keys.A && e.Control)
    {
     lvTasks.MultiSelect = true;
     foreach (ListViewItem item in lvTasks.Items)
     {
       item.Selected = true;
     }
    }
    if (e.KeyCode == Keys.Delete) 
    for (int i = lvTasks.SelectedItems.Count - 1; i >= 0; i--)
    {
     ListViewItem itm = lvTasks.SelectedItems[i];
     lvTasks.Items[itm.Index].Remove();
    }
}

编辑

您的行lvTasks.Items.Remove(lvTasks.SelectedItems[0]);

是问题。您只删除索引为0的项目。您需要在它们上循环。

编辑2 仅在您要删除所有项目时才有效。如果您确实只想删除选定的项目。更改for循环并删除列表：

for (int i = lvTasks.SelectedItems.Count - 1; i >= 0; i--)
{
 ListViewItem itm = lvTasks.SelectedItems[i];
 lvTasks.Items[itm.Index].Remove();
}

应该可以。

Answer 2

我会使用while循环：

if (e.KeyCode == Keys.Delete) 
{
   while (lvTasks.SelectedItems.Count > 0)
   {
      lvTasks.SelectedItems[0].Remove();
   }
}

已更正。谢谢塞萨尔！

选择然后删除所选列表项

2 个答案: