调用线程不能访问这个对象，因为它属于另一个线程

我的代码如下

public CountryStandards()
{
    InitializeComponent();
    try
    {
        FillPageControls();
    }
    catch (Exception ex)
    {
        MessageBox.Show(ex.Message, "Country Standards", MessageBoxButton.OK, MessageBoxImage.Error);
    }
}

/// <summary>
/// Fills the page controls.
/// </summary>
private void FillPageControls()
{
    popUpProgressBar.IsOpen = true;
    lblProgress.Content = "Loading. Please wait...";
    progress.IsIndeterminate = true;
    worker = new BackgroundWorker();
    worker.DoWork += new System.ComponentModel.DoWorkEventHandler(worker_DoWork);
    worker.ProgressChanged += new System.ComponentModel.ProgressChangedEventHandler(worker_ProgressChanged);
    worker.WorkerReportsProgress = true;
    worker.WorkerSupportsCancellation = true;
    worker.RunWorkerCompleted += new System.ComponentModel.RunWorkerCompletedEventHandler(worker_RunWorkerCompleted);
    worker.RunWorkerAsync();                    
}

private void worker_DoWork(object sender, System.ComponentModel.DoWorkEventArgs e)
{
    GetGridData(null, 0); // filling grid
}

private void worker_ProgressChanged(object sender, System.ComponentModel.ProgressChangedEventArgs e)
{
    progress.Value = e.ProgressPercentage;
}

private void worker_RunWorkerCompleted(object sender, System.ComponentModel.RunWorkerCompletedEventArgs e)
{
    worker = null;
    popUpProgressBar.IsOpen = false;
    //filling Region dropdown
    Standards.UDMCountryStandards objUDMCountryStandards = new Standards.UDMCountryStandards();
    objUDMCountryStandards.Operation = "SELECT_REGION";
    DataSet dsRegionStandards = objStandardsBusinessLayer.GetCountryStandards(objUDMCountryStandards);
    if (!StandardsDefault.IsNullOrEmptyDataTable(dsRegionStandards, 0))
        StandardsDefault.FillComboBox(cmbRegion, dsRegionStandards.Tables[0], "Region", "RegionId");

    //filling Currency dropdown
    objUDMCountryStandards = new Standards.UDMCountryStandards();
    objUDMCountryStandards.Operation = "SELECT_CURRENCY";
    DataSet dsCurrencyStandards = objStandardsBusinessLayer.GetCountryStandards(objUDMCountryStandards);
    if (!StandardsDefault.IsNullOrEmptyDataTable(dsCurrencyStandards, 0))
        StandardsDefault.FillComboBox(cmbCurrency, dsCurrencyStandards.Tables[0], "CurrencyName", "CurrencyId");

    if (Users.UserRole != "Admin")
        btnSave.IsEnabled = false;

}

/// <summary>
/// Gets the grid data.
/// </summary>
/// <param name="sender">The sender.</param>
/// <param name="pageIndex">Index of the page.( used in case of paging)   </pamam>
private void GetGridData(object sender, int pageIndex)
{
    Standards.UDMCountryStandards objUDMCountryStandards = new Standards.UDMCountryStandards();
    objUDMCountryStandards.Operation = "SELECT";
    objUDMCountryStandards.Country = txtSearchCountry.Text.Trim() != string.Empty ? txtSearchCountry.Text : null;
    DataSet dsCountryStandards = objStandardsBusinessLayer.GetCountryStandards(objUDMCountryStandards);
    if (!StandardsDefault.IsNullOrEmptyDataTable(dsCountryStandards, 0) && (chkbxMarketsSearch.IsChecked == true || chkbxBudgetsSearch.IsChecked == true || chkbxProgramsSearch.IsChecked == true))
    {
        DataTable objDataTable = StandardsDefault.FilterDatatableForModules(dsCountryStandards.Tables[0], "Country", chkbxMarketsSearch, chkbxBudgetsSearch, chkbxProgramsSearch);
        dgCountryList.ItemsSource = objDataTable.DefaultView;
    }
    else
    {
        MessageBox.Show("No Records Found", "Country Standards", MessageBoxButton.OK, MessageBoxImage.Information);
        btnClear_Click(null, null);
    }
}

该步骤遵循judmcountrystandards。Country = txtSearchCountry.Text.Trim() !=字符串。空的吗?txtSearchCountry。文本:null;在获取网格数据时抛出异常

调用线程不能访问此对象，因为有不同的线程拥有它。

这里出了什么问题?

当前回答

我在从WPF控件中选择的第二个项目上奇怪地遇到了这个错误。

原因是我将数据加载到RX SourceCache中，加载的元素将observablecollection作为导航属性包装到CollectionView中。observablecollection连接到UIThread，数据由WorkerThread加载。由于CollectionView只在显示第一个元素时被填充，不同线程的问题只发生在被选择的第二个项目上。

解决方案是将子列表作为ReadOnlyObservableCollections移动到ViewModel中，并根据当前选择的主元素筛选子元素表的完整列表。

2022-09-02 14:51:28

其他回答

另外，另一个解决方案是确保控件是在UI线程中创建的，而不是由后台工作线程创建的。

2017-02-23 08:27:08

出于某种原因，坎迪德的回答并不可信。尽管如此，它还是很有帮助的，因为它让我发现了这个，它非常有效:

System.Windows.Threading.Dispatcher.CurrentDispatcher.Invoke((Action)(() =>
{
   //your code here...
}));

2015-07-12 10:44:12

当我添加级联组合框到我的WPF应用程序时，我一直得到错误，并通过使用这个API解决了这个错误:

    using System.Windows.Data;

    private readonly object _lock = new object();
    private CustomObservableCollection<string> _myUiBoundProperty;
    public CustomObservableCollection<string> MyUiBoundProperty
    {
        get { return _myUiBoundProperty; }
        set
        {
            if (value == _myUiBoundProperty) return;
            _myUiBoundProperty = value;
            NotifyPropertyChanged(nameof(MyUiBoundProperty));
        }
    }

    public MyViewModelCtor(INavigationService navigationService) 
    {
       // Other code...
       BindingOperations.EnableCollectionSynchronization(AvailableDefectSubCategories, _lock );

    }

详情请见https://msdn.microsoft.com/query/dev14.query?appId=Dev14IDEF1&l=EN-US&k=k(System.Windows.Data.BindingOperations.EnableCollectionSynchronization);k(TargetFrameworkMoniker-.NETFramework,Version%3Dv4.7);k(DevLang-csharp)&rd=true

2018-06-15 19:00:40

这对我很有用。

new Thread(() =>
        {

        Thread.CurrentThread.IsBackground = false;
        Application.Current.Dispatcher.BeginInvoke(DispatcherPriority.Background, (SendOrPostCallback)delegate {

          //Your Code here.

        }, null);
        }).Start();

2018-06-15 15:41:52

正如这里提到的，Dispatcher。调用可以冻结UI。应该使用Dispatcher。BeginInvoke代替。

下面是一个方便的扩展类，可以简化检查和调用调度程序调用。

示例用法:(从WPF窗口调用)

this Dispatcher.InvokeIfRequired(new Action(() =>
{
    logTextbox.AppendText(message);
    logTextbox.ScrollToEnd();
}));

扩展类:

using System;
using System.Windows.Threading;

namespace WpfUtility
{
    public static class DispatcherExtension
    {
        public static void InvokeIfRequired(this Dispatcher dispatcher, Action action)
        {
            if (dispatcher == null)
            {
                return;
            }
            if (!dispatcher.CheckAccess())
            {
                dispatcher.BeginInvoke(action, DispatcherPriority.ContextIdle);
                return;
            }
            action();
        }
    }
}

2018-03-28 22:23:57

调用线程不能访问这个对象，因为它属于另一个线程

推荐文章

最新文章

标签