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

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

其他回答

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

你需要在UI线程上做。使用:

Dispatcher.BeginInvoke(new Action(() => {GetGridData(null, 0)}));

2013-03-05 11:27:36

如果你遇到这个问题，并且UI控件是在WPF中使用BitmapSource或ImageSource时在单独的工作线程上创建的，在将BitmapSource或ImageSource作为参数传递给任何方法之前，首先调用Freeze()方法。使用Application.Current.Dispatcher.Invoke()在这样的实例中不起作用

2015-11-25 12:59:13

这发生在我身上，因为我试图在另一个线程而不是UI线程中访问UI组件

像这样

private void button_Click(object sender, RoutedEventArgs e)
{
    new Thread(SyncProcces).Start();
}

private void SyncProcces()
{
    string val1 = null, val2 = null;
    //here is the problem 
    val1 = textBox1.Text;//access UI in another thread
    val2 = textBox2.Text;//access UI in another thread
    localStore = new LocalStore(val1);
    remoteStore = new RemoteStore(val2);
}

为了解决这个问题，将任何ui调用包装在Candide上面提到的答案中

private void SyncProcces()
{
    string val1 = null, val2 = null;
    this.Dispatcher.Invoke((Action)(() =>
    {//this refer to form in WPF application 
        val1 = textBox.Text;
        val2 = textBox_Copy.Text;
    }));
    localStore = new LocalStore(val1);
    remoteStore = new RemoteStore(val2 );
}

2016-06-27 07:59:41

根据您的需要，肯定有不同的方法来做到这一点。

我使用UI更新线程(它不是主UI线程)的一种方法是让线程开始一个循环，其中整个逻辑处理循环被调用到UI线程上。

例子:

public SomeFunction()
{
    bool working = true;
    Thread t = new Thread(() =>
    {
        // Don't put the working bool in here, otherwise it will 
        // belong to the new thread and not the main UI thread.
        while (working)
        {
            Application.Current.Dispatcher.Invoke(() =>
            {
                // Put your entire logic code in here.
                // All of this code will process on the main UI thread because
                //  of the Invoke.
                // By doing it this way, you don't have to worry about Invoking individual
                //  elements as they are needed.
            });
        }
    });
}

这样，代码就完全在主UI线程上执行。对于那些难以理解跨线程操作的业余程序员来说，这可能是一种专业方法。然而，对于更复杂的ui(特别是在执行动画时)，它很容易成为一个骗局。实际上，这只是为了伪造一个更新UI的系统，然后返回来处理任何已经触发的事件，以代替有效的跨线程操作。

2020-07-14 02:05:31

调用线程不能访问这个对象，因为它属于另一个线程

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