C# DataGrid.SelectedItem未绑定到当前选定的单元格

在好几次场合遇到了这个问题

在右键单击菜单或选择单元格中的组合框上查找SelectedItem或selected列时。SelectedItem将为空或先前选择的行

private void ComboBox_GotKeyboardFocus(object sender, KeyboardFocusChangedEventArgs e) {
// Correct  
m_BeginEditString = ((ComboBox)sender).SelectedValue.ToString(); 

// Wrong. selected item is last selected row, example clicking directly on combobox will not select row, and be null.
m_BeginEditRow = (RowItem)MyDataGrid.SelectedItem; 
}   

<DataGridTemplateColumn>
   <DataGridTemplateColumn.CellTemplate>
    <DataTemplate>
        <ComboBox SelectedItem="{Binding myItem, Mode=TwoWay, 
NotifyOnSourceUpdated=True, UpdateSourceTrigger=PropertyChanged}" 
ItemsSource="{Binding Source={StaticResource enum}}" 
SelectionChanged="ComboBox_Changed" 
LostKeyboardFocus="ComboBox_LostKeyboardFocus" 
GotKeyboardFocus="ComboBox_GotKeyboardFocus" />
        </DataTemplate>
   </DataGridTemplateColumn.CellTemplate>
 </DataGridTemplateColumn>

private void组合框\u获取KeyboardFocus（对象发送器，KeyboardFocusChangedEventArgs e）{
//正确的
m_BeginEditString=（（组合框）sender）.SelectedValue.ToString（）；
//错误。所选项目是最后选定的行，直接单击组合框将不会选择行，并且为空。
m_BeginEditRow=（RowItem）MyDataGrid.SelectedItem；
}   

您可以通过父对象进行访问，并尝试访问您想要的任何内容，而不是直接访问所选项目。这是另一种方法。我希望这对你有帮助

Combobox objMyButton = null;
        if (sender is Combobox)
        {
            objMyButton = (sender as Combobox );    
        }

        //You can access the parent object which means corresponding DataGridRow and do whatever you want

        for (var vis = sender as Visual; vis != null; vis = VisualTreeHelper.GetParent(vis) as Visual)
            if (vis is DataGridRow)
            {
                var row = (DataGridRow)vis;                 
                break;
            }

---

以完全不同的方式解决，感谢@Ramesh Muthiah的指导：

private void ComboBox_Changed(object sender, SelectionChangedEventArgs e) {
if (((ComboBox)sender).IsLoaded) { // disregard SelectionChangedEvent fired on population from binding
    if (e.RemovedItems.Count != 0) {
        for (Visual visual = (Visual)sender; visual != null; visual = (Visual)VisualTreeHelper.GetParent(visual)) { // Traverse tree to find corred selected item
            if (visual is DataGridRow) {
                DataGridRow row = (DataGridRow)visual;
                m_BeginEditRow = new MyRowItem((MyRowItem)row.Item); // Copy constructor, otherwise passed by reference
                break;
            }
        }
        MyEnum newItem = (MyEnum)e.AddedItems[0];
        MyEnum oldItem = (MyEnum)e.RemovedItems[0];
        if (m_BeginEditRow.Combo1 == newItem) {
            m_BeginEditRow.Combo1 = oldItem;
        } else {
            m_BeginEditRow.Combo2 = oldItem;
        }
        DoStuff(m_BeginEditRow, false);
    }
}

---

}

此组合框是否位于数据网格的单元格中？在您的评论中，您谈论的是单击，但看起来您正在处理“键盘焦点”事件。你能澄清一下吗？@glace ComboBox在DataGrid的单元格中：不明白为什么if（发送方是ComboBox）也能遍历可视化树。但是在这些处理程序上旋转了很多次。这样，当我想要m_BeginEditRow时，它就是新值，即使组合框还没有关闭