下降时DataGridCell是一个TextBlock，而上升时是TextBox

So, I have a DataGrid, which contains elements that look like this:

所以，我有一个DataGrid，其中包含如下所示的元素：

<DataGridTextColumn Header="Dto 1" Binding="{Binding Path=Dto1}">
    <DataGridTextColumn.EditingElementStyle>
        <Style TargetType="{x:Type TextBox}">
            <EventSetter Event="PreviewKeyDown" Handler="TextBox_PreviewKeyDown"/>
            <EventSetter Event="GotFocus" Handler="TextBox_GotFocus"/>
        </Style>
    </DataGridTextColumn.EditingElementStyle>
</DataGridTextColumn>

The PreviewKeyDown works perfectly fine, when I go up, I am able to get back to the cell with no problem. The way I see it, for all intents and purposes, I got a TextBox in there.

PreviewKeyDown工作得非常好，当我上升时，我能够毫无问题地回到单元格。我看到它的方式，无论出于什么意图和目的，我都有一个TextBox。

Now, when I try to go down from the cell in an event:

现在，当我试图在一个事件中从单元格下来时：

private void dgPropuestas_GotFocus(object sender, RoutedEventArgs e) {
        var cell = e.OriginalSource as DataGridCell;
        if (cell != null) {
            var cp = VisualTreeHelper.GetChild(VisualTreeHelper.GetChild(cell, 0), 0) as ContentPresenter;
            var tb = cp.Content as TextBlock;
            if (tb != null)
                tb.Focus();
        }
    }

(Note: I put the VisualTreeHelper method twice manually, I do have the FindVisualChildren one, but I went through the tree manually and as an act of desperation to speed up a bit, I put it manually)

（注意：我手动将VisualTreeHelper方法放两次，我有一个FindVisualChildren方法，但是我手动浏览了树，并且作为一种绝望的行为加速了一点，我手动把它放了）

If I try to declare tb as cp.Content as TextBox I get a null. For some reason, the ContentPresenter has inside a TextBlock, not a TextBox. FindVisualChildren(cell) returns an empty IEnumerable.

如果我尝试将tb声明为cp.Content作为TextBox，我得到一个null。出于某种原因，ContentPresenter内部有TextBlock，而不是TextBox。 FindVisualChildren（cell）返回一个空的IEnumerable。

Why is this a problem? Because I need to be able to call SelectAll() on the text, and textBlock doesn't offer that option. Any help is greatly appreciated. Thanks in advance!

为什么这是个问题？因为我需要能够在文本上调用SelectAll（），而textBlock不提供该选项。任何帮助是极大的赞赏。提前致谢！

Later Edit: Apparently, when not in edit mode, the datagrid contains a textblock. When in edit mode, a textbox. Now, datagrid.BeginEdit() doesn't seem to work, as it doesn't initialize the TextBox nor does it trigger the event of PrepareCellForEditing.

稍后编辑：显然，当不处于编辑模式时，datagrid包含一个文本块。在编辑模式下，文本框。现在，datagrid.BeginEdit（）似乎不起作用，因为它没有初始化TextBox，也没有触发PrepareCellForEditing事件。

2 个解决方案

#1

Totally approaching this the wrong way. You subscribe to events on a TextBox, so the sender will always be said TextBox.

完全接近这个错误的方式。您订阅了TextBox上的事件，因此始终会将发件人称为TextBox。

#2

Given that the TextBox would not get initialized with BeginEditing() nor with isEditing = true, the problem was fixed by declaring the fields as textbox and forcing them upon the datagrid:

鉴于TextBox不会使用BeginEditing（）或isEditing = true进行初始化，因此通过将字段声明为文本框并在数据网格上强制它们来修复问题：

<DataGridTemplateColumn Header="Dto 2">
                            <DataGridTemplateColumn.CellTemplate>
                                <DataTemplate>
                                    <TextBox Text="{Binding Dto2}" GotFocus="TextBox_GotFocus" PreviewKeyDown="TextBox_PreviewKeyDown"/>
                                </DataTemplate>
                            </DataGridTemplateColumn.CellTemplate>
                        </DataGridTemplateColumn>

#1