我正在尝试将可观察集合绑定到 DataGrid,我想在数据网格中编辑任何行时发出通知。
我的代码可以很好地在添加或删除记录时发出通知,但在编辑记录时不会发出通知。
请告诉我这是否是在 MVVM 中使用可观察集合进行绑定的正确方法以及我是否遗漏了某些内容。提前致谢。
public class studentViewModel : INotifyPropertyChanged
{
#region constructor
public studentViewModel()
{
_student = new studentModel();
myCollection = new ObservableCollection<studentModel>();
myCollection.Add(_student);
myCollection.CollectionChanged += new System.Collections.Specialized.NotifyCollectionChangedEventHandler(myCollection_CollectionChanged);
}
void myCollection_CollectionChanged(object sender, System.Collections.Specialized.NotifyCollectionChangedEventArgs e)
{
//throw new NotImplementedException();
System.Windows.MessageBox.Show(e.Action.ToString());
}
#endregion
#region properties
studentModel _student;
ObservableCollection<studentModel> _myCollection;
public ObservableCollection<studentModel> myCollection
{
get { return _myCollection; }
set
{
if (_myCollection != value)
{
_myCollection = value;
raisePropertyChange("myCollection");
}
}
}
public int rollNo
{
get { return _student.rollNo; }
set
{
if (value != _student.rollNo)
{
_student.rollNo = value;
raisePropertyChange("rollNo");
}
}
}
public string firstName
{
get { return _student.firstName; }
set
{
if (value != _student.firstName)
{
_student.firstName = value;
raisePropertyChange("firstName");
}
}
}
public string lastName
{
get { return _student.lastName; }
set
{
if (value != _student.lastName)
{
_student.lastName = value;
raisePropertyChange("lastName");
}
}
}
#endregion
#region INotifyPropertyChanged Members
public event PropertyChangedEventHandler PropertyChanged;
public void raisePropertyChange(string propertyName)
{
if (PropertyChanged != null)
{
PropertyChanged(this,new PropertyChangedEventArgs(propertyName));
}
}
#endregion
}
public class studentModel
{
public int rollNo { get; set; }
public string firstName { get; set; }
public string lastName { get; set; }
}
xaml 是
<Window.Resources>
<local:studentViewModel x:Key="StudentsDetails" />
</Window.Resources>
<Grid DataContext="{StaticResource StudentsDetails}">
<DataGrid ItemsSource="{Binding Path=myCollection, Source={StaticResource StudentsDetails}, Mode=TwoWay, UpdateSourceTrigger=PropertyChanged}"
Name="studentsGrid" CanUserAddRows="True" AutoGenerateColumns="True">
</DataGrid>
</Grid>
当添加或删除记录时,ObservableCollection 将通知 UI,但是not当编辑记录时。由已更改的对象来通知它已更改。
在您的情况下,当修改一行时,更改的对象的类型是studentModel
.
因此,如果您希望 UI 在该对象发生更改时收到通知,您需要实施 INotifyPropertyChanged http://msdn.microsoft.com/en-us/library/ms229614.aspx on studentModel
too..
e.g.
public class studentModel : INotifyPropertyChanged
.....
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