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我工作的窗口有一個DataGrid綁定到一個可觀察集合,該集合包含源自數據庫表的項目。我想在輸入網格中的一行時記住原始項目,並且當網格中的行保留時,我想將添加或更新的項目提交到數據庫。我需要原始和修改的值來找出發生了什麼變化。WPF DataGrid行輸入和行離開事件
基本上,我想要在數據表中輸入數據時,實現與Visual Studio或SQL Developer Studio中相同的行爲。
有誰知道該怎麼做?謝謝。
在我當前的實現中,當字段發生更改時,我無法獲得項目的原始值,並且每個更改的字段都會調用OnItemChanged,我寧願一次提交整行。
這是我的觀點:
<Window x:Class="TourMan.Views.EditPersonsView"
xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
xmlns:d="http://schemas.microsoft.com/expression/blend/2008"
xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"
mc:Ignorable="d"
Title="Persons">
<Grid>
<DataGrid AutoGenerateColumns="False" HorizontalContentAlignment="Center" ItemsSource="{Binding Persons}"
RowBackground="LightGoldenrodYellow" AlternatingRowBackground="PaleGoldenrod" AlternationCount="2"
CanUserAddRows="True" CanUserDeleteRows="True" >
<DataGrid.Columns>
<DataGridTextColumn Header="Name" Width ="100" Binding="{Binding Name}"/>
<DataGridTextColumn Header="Address" Width ="250" Binding="{Binding Addresses}"/>
</DataGrid.Columns>
</DataGrid>
</Grid>
</Window>
和視圖模型:
class EditPersonsViewModel
{
public ObservableCollection<Person> Persons { get; }
public EditPersonsViewModel()
{
Persons = Engine.Instance().GetPersons();
foreach (var person in Persons)
{
person.PropertyChanged += OnItemChanged;
}
Persons.CollectionChanged += OnCollectionChanged;
}
private void OnCollectionChanged(object sender, NotifyCollectionChangedEventArgs e)
{
if (e.Action == NotifyCollectionChangedAction.Add && e.NewItems != null)
{
foreach (var item in e.NewItems)
{
Engine.Instance().AddPerson((Person)item);
((Person)item).PropertyChanged += OnItemChanged;
}
}
else if (e.Action == NotifyCollectionChangedAction.Remove && e.OldItems != null)
{
foreach (var item in e.OldItems)
{
Engine.Instance().DeletePerson(((Field)item));
}
}
}
private void OnItemChanged(object sender, PropertyChangedEventArgs e)
{
Engine.Instance().UpdatePerson((Person)sender, null);
}
}