WPF 数据网格组合框列：如何管理选择更改的事件？
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原文地址: http://stackoverflow.com/questions/19322271/
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WPF datagrid combobox column: how to manage event of selection changed?
提问by FrancescoDS
I have a datagrid, with a combobox column
我有一个数据网格，带有一个组合框列
<DataGridComboBoxColumn x:Name="DataGridComboBoxColumnBracketType" Width="70" Header="Tipo di staffa" SelectedValueBinding="{Binding type, UpdateSourceTrigger=PropertyChanged}">
</DataGridComboBoxColumn>
I want an event that is fired only when the user changes the value into the combobox. How can I resolve this?
我想要一个仅当用户将值更改为组合框时才会触发的事件。我该如何解决这个问题？
回答by kevinpo
I found a solution to this on CodePlex. Here it is, with some modifications:
我在CodePlex上找到了解决方案。这是，经过一些修改：
<DataGridComboBoxColumn x:Name="Whatever">
<DataGridComboBoxColumn.EditingElementStyle>
<Style TargetType="{x:Type ComboBox}">
<EventSetter Event="SelectionChanged" Handler="SomeSelectionChanged" />
</Style>
</DataGridComboBoxColumn.EditingElementStyle>
</DataGridComboBoxColumn>
and in the code-behind:
并在代码隐藏中：
private void SomeSelectionChanged(object sender, SelectionChangedEventArgs e)
{
var comboBox = sender as ComboBox;
var selectedItem = this.GridName.CurrentItem;
}
回答by Kaloyan Penov
And the xaml code provided by @kevinpo from CodePlex and help from David Mohundro's blog, programatically:
以及 CodePlex 的 @kevinpo 提供的 xaml 代码和David Mohundro 博客的帮助，以编程方式：
var style = new Style(typeof(ComboBox));
style.Setters.Add(new EventSetter(ComboBox.SelectionChangedEvent, new SelectionChangedEventHandler(SomeSelectionChanged)));
dataGridComboBoxColumn.EditingElementStyle = style;
回答by Mr Rubix
To Complete Kevinpo answer, for the code behind you should add some protection because the selectionChanged event is triggered 2 time with a datagridcolumncombobox:
要完成 Kevinpo 的回答，您应该为后面的代码添加一些保护，因为 selectionChanged 事件是使用 datagridcolumncombobox 触发的 2 次：
1) first trigger : when you selected a new item
1）第一次触发：当你选择一个新项目时
2) Second trigger : when you click on an other datagridcolumn after you selected a new item
2）第二次触发：当您选择一个新项目后单击另一个数据网格列时
The problem is that on the second trigger the ComboBox value is null because you don't have changed the selected item.
问题是在第二个触发器上，ComboBox 值为空，因为您没有更改所选项目。
private void SomeSelectionChanged(object sender, SelectionChangedEventArgs e)
{
var comboBox = sender as ComboBox;
if (comboBox.SelectedItem != null)
{
YOUR CODE HERE
}
}
That was my problem, I wish it will help someone else !
那是我的问题，我希望它能帮助别人！
