什么是“按下了删除键"?WPF Datagrid 的事件? [英] What is the "pressed the delete key" event for the WPF Datagrid?

问题描述

我想让用户突出显示 WPF DataGrid 上的一行，然后按删除键删除该行.

• 该功能已经内置到网格的 UI 中，因此对于用户而言，该行消失了
• 我目前在 SelectionChanged 事件(下面的代码)上处理此问题
• 我遍历所有e.RemovedItems"并使用 LINQ 删除它们

• the functionality is already built into the UI of the grid, so to the user, the row disappears
• I currently handle this on the SelectionChanged event (code below)
• I loop through all the "e.RemovedItems" and delete them with LINQ

问题是:即使您只是选择一行并移开它，也会触发选择更改并且该行在 e.RemovedItems 中(这很奇怪，为什么要简单地选择一些东西把它放在一个 RemovedItems 容器中?).

Problem is: even when you simply select a row and move off of it, selection change is fired and that row is in e.RemovedItems (which is odd, why would simply selecting something put it in a RemovedItems container?).

所以我正在寻找 DeleteKeyPressed 事件，以便我可以简单地处理它.那个事件叫什么?

So I am looking for a DeleteKeyPressed event so I can simply handle it. What is that event called?

我使用的是 2009 年 3 月的工具包.

I am using the March 2009 toolkit.

XAML:

<Grid DockPanel.Dock="Bottom">
    <toolkit:DataGrid x:Name="TheDataGrid" 
                      SelectionChanged="TheDataGrid_SelectionChanged"
                      AutoGenerateColumns="True"
                      RowEditEnding="TheDataGrid_RowEditEnding"/>

代码隐藏:

private void TheDataGrid_SelectionChanged(object sender, System.Windows.Controls.SelectionChangedEventArgs e)
{
    if (e.RemovedItems.Count > 0)
    {
        Message.Text = "The following were removed: ";
        foreach (object obj in e.RemovedItems)
        {
            Customer customer = obj as Customer;
            Message.Text += customer.ContactName + ",";
            _db.Order_Details.DeleteAllOnSubmit(
                customer.Orders.SelectMany(o => o.Order_Details));
            _db.Orders.DeleteAllOnSubmit(customer.Orders);
            _db.Customers.DeleteOnSubmit(customer);
        } 
    }

    try
    {
        _db.SubmitChanges();
    }
    catch (Exception ex)
    {
        Message.Text = ex.Message;
    }
}

---

答案:

谢谢 lnferis，这正是我要找的，这是我完成的数据网格删除处理事件，注意 KeyDown 事件由于某种原因没有触发.

---

ANSWER:

Thanks lnferis, that was exactly what I was looking for, here is my finished delete handling event for the datagrid, note the KeyDown event doesn't fire for some reason.

XAML:

<toolkit:DataGrid x:Name="TheDataGrid" 
                  KeyDown="TheDataGrid_KeyDown"
                  PreviewKeyDown="TheDataGrid_PreviewKeyDown"
                  AutoGenerateColumns="True"
                  RowEditEnding="TheDataGrid_RowEditEnding"/>

代码隐藏

private void TheDataGrid_PreviewKeyDown(object sender, KeyEventArgs e)
{
    if (e.Key == Key.Delete)
    {
        var grid = (DataGrid)sender;

        if (grid.SelectedItems.Count > 0)
        {
            string checkMessage = "The following will be removed: ";

            foreach (var row in grid.SelectedItems)
            {
                Customer customer = row as Customer;
                checkMessage += customer.ContactName + ",";
            }
            checkMessage = Regex.Replace(checkMessage, ",$", "");

            var result = MessageBox.Show(checkMessage, "Delete", MessageBoxButton.OKCancel);
            if (result == MessageBoxResult.OK)
            {
                foreach (var row in grid.SelectedItems)
                {
                    Customer customer = row as Customer;
                    _db.Order_Details.DeleteAllOnSubmit(
                        customer.Orders.SelectMany(o => o.Order_Details));
                    _db.Orders.DeleteAllOnSubmit(customer.Orders);
                    _db.Customers.DeleteOnSubmit(customer);
                }
                _db.SubmitChanges();
            }
            else
            {
                foreach (var row in grid.SelectedItems)
                {
                    Customer customer = row as Customer;
                    LoadData();
                    _db.Refresh(System.Data.Linq.RefreshMode.OverwriteCurrentValues, customer); //TODO: this doesn't refresh the datagrid like the other instance in this code
                }
            }
        }
    }
}

private void TheDataGrid_KeyDown(object sender, KeyEventArgs e)
{
    Console.WriteLine("never gets here for some reason");
}

推荐答案

RemovedItems 项目反映了从选择中移除的项目，而不是从网格中移除的项目.

The RemovedItems items reflects the items removed from the selection, and not from the grid.

处理 PreviewKeyDown 事件，并使用 SelectedItems 属性删除那里的选定行:

Handle the PreviewKeyDown event, and use the SelectedItems property to delete the selected rows there:

private void PreviewKeyDownHandler(object sender, KeyEventArgs e) {
    var grid = (DataGrid)sender;
    if ( Key.Delete == e.Key ) {
        foreach (var row in grid.SelectedItems) {
            ... // perform linq stuff to delete here
        }
    }
}

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