我正在创建一个WPF应用程序,使用Entity Framework、CRUD操作和MVVM,允许用户输入有关其员工的一些详细信息。目前为止,我有两个ListViews。其中一个包含员工姓名列表(listview1),而另一个(listview2)列出了他们的详细信息,例如出生日期、地址等。下面的图像将更好地说明我正在创建的内容:
我正在使用CollectionViewSoruce来使我能够在从listbox1选择特定名称时筛选listview2上的结果。到目前为止,我能够做到这一点,但是当我添加或删除员工时,它会抛出异常;
这里有一些可能有用的代码片段。
ViewModel:
如您所见,我已将筛选器放置在
此外,如果我从ListView2而不是从ListView1选择一行,则还会产生
非常感谢您的帮助和建议。同时,抱歉问题比较复杂!
![ListView](https://istack.dev59.com/3OTqd.webp)
An unhandled exception of type 'System.StackOverflowException' occurred in *.UI.exe
这里有一些可能有用的代码片段。
ViewModel:
private EmployeeListViewModel()
: base("")
{
EmployeeList = new ObservableCollection<EmployeeViewModel>(GetEmployees());
this._employeeCol = new ListCollectionView(this.employeeList);
}
private ListCollectionView _employeeCol;
public ICollectionView EmployeeCollection
{
get { return this._employeeCol; }
}
private ObservableCollection<EmployeeViewModel> employeeList;
public ObservableCollection<EmployeeViewModel> EmployeeList
{
get { return employeeList; }
set
{
employeeList = value;
OnPropertyChanged("EmployeeList");
}
}
private EmployeeViewModel selectedEmployee = null;
public EmployeeViewModel SelectedEmployee
{
get
{
return selectedEmployee;
}
set
{
selectedEmployee = value;
OnPropertyChanged("SelectedEmployee");
EmployeeCollection.Filter = new Predicate<object>(o => SelectedEmployee != null && o != null && ((EmployeeViewModel)o).EmployeeID == SelectedEmployee.EmployeeID);
}
}
internal ObservableCollection<EmployeeViewModel> GetEmployees()
{
if (employeeList == null)
employeeList = new ObservableCollection<EmployeeViewModel>();
employeeList.Clear();
foreach (DataObjects.Employee i in new EmployeeRepository().GetAllEmployees())
{
EmployeeViewModel c = new EmployeeViewModel(i);
employeeList.Add(c);
}
return employeeList;
}
ListView2 - 员工列表视图;
<ListView Name="lsvEmpoyeeList" Height="170" Width="700"
ScrollViewer.VerticalScrollBarVisibility="Visible"
ScrollViewer.HorizontalScrollBarVisibility="Visible"
HorizontalAlignment="Center"
IsSynchronizedWithCurrentItem="True"
ItemsSource="{Binding EmployeeCollection}"
SelectedItem="{Binding SelectedEmployee}">
<ListView.View>
<GridView>
<GridViewColumn Header="Position" DisplayMemberBinding="{Binding Position}" Width="100" />
<GridViewColumn Header="DateOfBirth" DisplayMemberBinding="{Binding DateOfBirth, StringFormat={}\{0:dd/MM/yyyy\}}" Width="100" />
</GridView>
</ListView.View>
</ListView>
ListView1 - 员工设置视图;
<ListView Height="380" HorizontalAlignment="Left" Name="lsNames" VerticalAlignment="Top" Width="170"
ScrollViewer.VerticalScrollBarVisibility="Visible"
ScrollViewer.HorizontalScrollBarVisibility="Visible"
SelectedItem="{Binding SelectedEmployee}"
ItemsSource="{Binding EmployeeList}" Grid.RowSpan="2" Grid.Row="1">
<ListView.View>
<GridView>
<GridViewColumn Header="FirstName" DisplayMemberBinding="{Binding FirstName}" Width="80" />
<GridViewColumn Header="Surname" DisplayMemberBinding="{Binding Surname}" Width="80" />
</GridView>
</ListView.View>
</ListView>
<ContentControl Grid.Column="1" Grid.Row="1" HorizontalAlignment="Center"
Content="{Binding}" ContentTemplate="{StaticResource EmployeeListView}" />
如您所见,我已将筛选器放置在
setaccessor
中。我曾尝试将其放置于构造函数中,但似乎没有任何细节出现在ListView2上。此外,如果我从ListView2而不是从ListView1选择一行,则还会产生
StackOverFlowException
,我不确定为什么会这样。非常感谢您的帮助和建议。同时,抱歉问题比较复杂!
SelectedEmployee
的 getter 方法是怎么实现的?你那里有打字错误吗? - Jehof