在使用ItemsSource时，将项目从一个列表框移动到另一个列表框并再次返回并获得Operation是无效的
本文关键字：列表 另一个 返回 无效 Operation 移动 项目 一个 ItemsSource | 更新日期: 2023-09-27 17:50:22
我有两个列表框。每个都从SQLight查询中获取数据。用户可以通过双击项目进行选择，它应该从LB1中删除它并将其放置在LB2中。用户可以选择从LB2中删除，它应该移回LB1，直到他们对所选内容满意为止。我使用从LB2保存的数据来过滤掉在LB1中发现的任何项目(按代码)。一旦用户对所选项目感到满意，就将LB2数据保存回DB。用户可以选择随时返回UI，并根据需要添加/删除项目。
我使用2 x ObservableCollections来填充LB1和LB2。我使用模板来控制这两个LB的布局。也就是说，一旦条目在一列中达到10项，它就会"溢出"到LB中的新列中。
我可以让LB1正确填充，甚至将项目移动到LB2，但当我想再次移动它时，我得到…
"Operation is not valid while ItemsSource is in use. Access and modify elements with ItemsControl.ItemsSource instead."
我是WPF c#的新手，需要关于如何解决这个问题的明确指导。(一直在努力解决这个4周现在)。解决方案需要应用于两个listbox。如有任何帮助，我将不胜感激。
请查看附件中的代码和注释…
CS…
using System;
using System.Windows;
using System.Windows.Input;
using System.Windows.Controls;
using System.Data;
using System.Data.SQLite;
using System.Collections;
using System.Collections.ObjectModel;
using System.Collections.Generic;
using PTWS.Class_Lib;
using System.ComponentModel;
using System.Windows.Data;
using System.Windows.Media;
namespace PTWS.MainPanelControls.FormControls.Permits
{
/// <summary>
/// Interaction logic for ColdWorkDraftUControl.xaml
/// </summary>
public partial class ColdWorkDraftUControl : UserControl
{
PTWDatabase db = new PTWDatabase();
ObservableCollection<CertificateLookup> CertificateLookupList = new ObservableCollection<CertificateLookup>();
ObservableCollection<CertificateSelected> CertificateSelectedList = new ObservableCollection<CertificateSelected>();
public ColdWorkDraftUControl()
{
InitializeComponent();
LoadDataCertificateLookup();
// all works great untill I uncomment the next line
//LoadDataCertificateSelected();
}
private void LoadDataCertificateLookup()
{
try
{
DataTable conditions;
String query = "select lc.Section '"Section'""
+ ", lc.Description '"Description'""
+ ", lc.SortOrder '"SortOrder'" "
+ "from LookupConditions lc "
+ "where not exists (select 1 from SelectedConditions sc where sc.Code = lc.Code and sc.PermitID = 'CWP-12-00001') "
+ "and lc.Section = 'Certificates'";
conditions = db.GetDataTable(query);
foreach (DataRow r in conditions.Rows)
{
CertificateLookupList.Add(new CertificateLookup()
{
Section = r["Section"].ToString(),
Description = r["Description"].ToString(),
SortOrder = r["SortOrder"].ToString()
});
}
listBoxCertificateLookup.ItemsSource = CertificateLookupList;
}
catch (Exception fail)
{
String error = "The following error has occurred:'n'n";
error += fail.Message.ToString() + "'n'n";
MessageBox.Show(error);
}
}
void LoadDataCertificateSelected()
{
try
{
DataTable conditions;
String query = "select Section '"Section'""
+ ", Description '"Description'""
+ ", SortOrder '"SortOrder'"";
query += "from SelectedConditions where PermitID = 'CWP-12-00001' and Section = 'Certificates'";
conditions = db.GetDataTable(query);
foreach (DataRow r in conditions.Rows)
{
CertificateSelectedList.Add(new CertificateSelected()
{
selectedSection = r["Section"].ToString(),
selectedDescription = r["Description"].ToString(),
selectedSortOrder = r["SortOrder"].ToString()
});
}
listBoxCertificateSelected.DataContext = CertificateSelectedList;
}
catch (Exception fail)
{
String error = "The following error has occurred:'n'n";
error += fail.Message.ToString() + "'n'n";
MessageBox.Show(error);
}
}
private void listBoxCertificateLookup_MouseDoubleClick(object sender, MouseButtonEventArgs e)
{
try
{
ListBoxItem myListBoxItem =
(ListBoxItem)(listBoxCertificateLookup.ItemContainerGenerator.ContainerFromItem(listBoxCertificateLookup.Items.CurrentItem));
// listBoxCertificateSelected.DataContext = null;
listBoxCertificateSelected.Items.Add(myListBoxItem);
}
catch (Exception fail)
{
String error = "The following error has occurred:'n'n";
error += fail.Message.ToString() + "'n'n";
MessageBox.Show(error);
}
}
private void listBoxCertificateSelected_MouseDoubleClick(object sender, MouseButtonEventArgs e)
{
try
{
ListBoxItem myListBoxItem =
(ListBoxItem)(listBoxCertificateSelected.ItemContainerGenerator.ContainerFromItem(listBoxCertificateSelected.Items.CurrentItem));
//listBoxCertificateLookup.DataContext = null;
listBoxCertificateLookup.Items.Add(myListBoxItem);
}
catch (Exception fail)
{
String error = "The following error has occurred:'n'n";
error += fail.Message.ToString() + "'n'n";
MessageBox.Show(error);
}
}
}
}
XAML…
<UserControl x:Class="PTWS.MainPanelControls.FormControls.Permits.ColdWorkDraftUControl"
xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"
xmlns:d="http://schemas.microsoft.com/expression/blend/2008"
mc:Ignorable="d"
d:DesignHeight="300" d:DesignWidth="300">
<Grid>
<ListBox Name="listBoxCertificateLookup"
ItemsSource="{Binding CertificateSelectedList}"
MouseDoubleClick="listBoxCertificateLookup_MouseDoubleClick"
IsSynchronizedWithCurrentItem="True"
HorizontalAlignment="Left" Width="300" Height="75" VerticalAlignment="Top" >
<ListBox.ItemTemplate>
<DataTemplate>
<StackPanel Height="23" Orientation="Horizontal">
<TextBlock Text="{Binding Path=Description}" VerticalAlignment="Top" />
</StackPanel>
</DataTemplate>
</ListBox.ItemTemplate>
<ListBox.ItemsPanel>
<ItemsPanelTemplate>
<WrapPanel IsItemsHost="True" Orientation="Vertical" />
</ItemsPanelTemplate>
</ListBox.ItemsPanel>
</ListBox>
<ListBox Name="listBoxCertificateSelected"
ItemsSource="{Binding}"
MouseDoubleClick="listBoxCertificateSelected_MouseDoubleClick"
HorizontalAlignment="Left" Width="300" Height="75" VerticalAlignment="Top" Margin="0,153,0,0">
<ListBox.ItemTemplate>
<DataTemplate>
<StackPanel Height="23" Orientation="Horizontal">
<TextBlock Name="textBlock" Text="{Binding Path=selectedDescription}" VerticalAlignment="Top" />
</StackPanel>
</DataTemplate>
</ListBox.ItemTemplate>
<ListBox.ItemsPanel>
<ItemsPanelTemplate>
<WrapPanel IsItemsHost="True" Orientation="Vertical" />
</ItemsPanelTemplate>
</ListBox.ItemsPanel>
</ListBox>
</Grid>
</UserControl>
类…
using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
namespace PTWS.Class_Lib
{
class CertificateLookup
{
public string Section { get; set; }
public string Description {get; set;}
public string SortOrder { get; set; }
public string selectedSection { get; set; }
public string selectedDescription { get; set; }
public string selectedSortOrder { get; set; }
}
}
修改了CS文件mouseDoubleClick事件(对两个列表框进行了适当的修改)…
CertificateLookup myListBoxItem = (CertificateLookup)((ListBox)sender).SelectedItem;
CertificateSelectedList.Add(new CertificateSelected()
{
selectedDescription = myListBoxItem.Description
});
CertificateLookupList.Remove(myListBoxItem);
您的问题是您正在向ListBox添加项，而不是向ListBox绑定的集合添加和删除项。
您应该直接添加/删除CertificateSelectedList和CertificateLookupList，而不是执行:listBoxCertificateSelected.Items.Add(myListBoxItem);。