Grid.children.clear 线程错误 xmpp wpf
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【中文标题】Grid.children.clear 线程错误 xmpp wpf【英文标题】：Grid.children.clear thread error xmpp wpf 【发布时间】：2013-05-31 07:01:45 【问题描述】：我正在调用具有Grid.Children.Clear() 功能的方法。从不同的方法调用它时效果很好。但是当我从 xmpp_onmessage 方法调用我的方法时。我遇到错误。 “调用线程无法访问此对象，因为不同的线程拥有它。”
这里是包含 Grid.Children.Clear() 的方法：
private void ConstructChatView(Boolean isChat)
System.Uri resourceUri = new System.Uri("Public/Images/chat_green-textarea.png", UriKind.Relative);
StreamResourceInfo streamInfo = Application.GetResourceStream(resourceUri);
System.Uri resourceUri2 = new System.Uri("Public/Images/chat_green-textarea-tail.png", UriKind.Relative);
StreamResourceInfo streamInfo2 = Application.GetResourceStream(resourceUri2);
System.Uri resourceUri3 = new System.Uri("Public/Images/chat_blue-textarea.png", UriKind.Relative);
StreamResourceInfo streamInfo3 = Application.GetResourceStream(resourceUri3);
System.Uri resourceUri4 = new System.Uri("Public/Images/chat_blue-textarea-tail.png", UriKind.Relative);
StreamResourceInfo streamInfo4 = Application.GetResourceStream(resourceUri4);
BitmapFrame temp = BitmapFrame.Create(streamInfo.Stream);
var brush = new ImageBrush();
brush.ImageSource = temp;
BitmapFrame temp2 = BitmapFrame.Create(streamInfo2.Stream);
BitmapFrame temp3 = BitmapFrame.Create(streamInfo3.Stream);
var brush2 = new ImageBrush();
brush2.ImageSource = temp3;
BitmapFrame temp4 = BitmapFrame.Create(streamInfo4.Stream);
int ctr = 0;
chatGrid.Children.Clear();
if (isChat == true)
for (int i = 0; i < _messageView.Count; i++)
if ((!_messageView.ElementAt(i).Message.ToString().Trim().Equals("")))
RowDefinition chatGridRow1 = new RowDefinition();
RowDefinition chatGridRow2 = new RowDefinition();
RowDefinition chatGridRow3 = new RowDefinition();
chatGrid.RowDefinitions.Add(chatGridRow1);
chatGrid.RowDefinitions.Add(chatGridRow2);
chatGrid.RowDefinitions.Add(chatGridRow3);
if (_messageView.ElementAt(i).IsMe == true)
TextBlock Message = new TextBlock();
Message.Foreground = Brushes.White;
Message.Padding = new Thickness(10, 10, 10, 10);
Message.HorizontalAlignment = HorizontalAlignment.Right;
Message.Margin = new Thickness(0, 0, 5, 0);
Message.Background = brush2;
Message.TextWrapping = TextWrapping.Wrap;
Message.Text = _messageView.ElementAt(i).Message;
Grid.SetRow(Message, ctr);
Grid.SetColumn(Message, 0);
ctr++;
Image Bluetail = new Image();
Bluetail.Source = temp4;
Bluetail.HorizontalAlignment = HorizontalAlignment.Right;
Bluetail.Height = 10;
Bluetail.Width = 20;
Bluetail.Margin = new Thickness(0, -(0.7), 10, 0);
Grid.SetRow(Bluetail, ctr);
ctr++;
Label Sender = new Label();
Sender.Foreground = Brushes.White;
Sender.Margin = new Thickness(0, 0, 0, 10);
Sender.HorizontalAlignment = HorizontalAlignment.Right;
Sender.Content = "Sent By : " + _messageView.ElementAt(i).Name.ToString() + " " + _messageView.ElementAt(i).DateCreated.ToString();
Grid.SetRow(Sender, ctr);
Grid.SetColumn(Sender, 0);
ctr++;
chatGrid.Children.Add(Message);
chatGrid.Children.Add(Bluetail);
chatGrid.Children.Add(Sender);
else
TextBlock Message = new TextBlock();
Message.Foreground = Brushes.White;
Message.Padding = new Thickness(10, 10, 10, 10);
Message.HorizontalAlignment = HorizontalAlignment.Left;
Message.Margin = new Thickness(5, 0, 0, 0);
Message.Background = brush;
Message.TextWrapping = TextWrapping.Wrap;
Message.Text = _messageView.ElementAt(i).Message;
Grid.SetRow(Message, ctr);
Grid.SetColumn(Message, 0);
ctr++;
Image Greentail = new Image();
Greentail.Source = temp2;
Greentail.HorizontalAlignment = HorizontalAlignment.Left;
Greentail.Height = 10;
Greentail.Width = 20;
Greentail.Margin = new Thickness(10, -(0.7), 5, 0);
Grid.SetRow(Greentail, ctr);
ctr++;
Label Sender = new Label();
Sender.Foreground = Brushes.White;
Sender.Margin = new Thickness(0, 0, 0, 10);
Sender.HorizontalAlignment = HorizontalAlignment.Left;
Sender.Content = "Sent By : " + _messageView.ElementAt(i).Name.ToString() + " " + _messageView.ElementAt(i).DateCreated.ToString();
Grid.SetRow(Sender, ctr);
Grid.SetColumn(Sender, 0);
ctr++;
chatGrid.Children.Add(Message);
chatGrid.Children.Add(Greentail);
chatGrid.Children.Add(Sender);
else
for (int i = 0; i < _messageView.Count; i++)
if (_messageView.ElementAt(i).IsMe == true && (!_messageView.ElementAt(i).Message.ToString().Trim().Equals("")))
RowDefinition chatGridRow1 = new RowDefinition();
RowDefinition chatGridRow2 = new RowDefinition();
RowDefinition chatGridRow3 = new RowDefinition();
chatGrid.RowDefinitions.Add(chatGridRow1);
chatGrid.RowDefinitions.Add(chatGridRow2);
chatGrid.RowDefinitions.Add(chatGridRow3);
TextBlock Message = new TextBlock();
Message.Foreground = Brushes.White;
Message.Margin = new Thickness(0, 10, 300, 0);
Message.Padding = new Thickness(10, 10, 10, 10);
Message.HorizontalAlignment = HorizontalAlignment.Left;
Message.Background = brush;
Message.TextWrapping = TextWrapping.Wrap;
Message.Text = _messageView.ElementAt(i).Message;
Grid.SetRow(Message, ctr);
Grid.SetColumn(Message, 0);
ctr++;
Image Greentail = new Image();
Greentail.Source = temp2;
Greentail.HorizontalAlignment = HorizontalAlignment.Left;
Greentail.Height = 10;
Greentail.Width = 20;
Greentail.Margin = new Thickness(5, -(0.7), 0, 0);
Grid.SetRow(Greentail, ctr);
ctr++;
Label Sender = new Label();
Sender.Foreground = Brushes.White;
Sender.Margin = new Thickness(0, 0, 0, 10);
Sender.Content = "Sent By : " + _messageView.ElementAt(i).Name.ToString() + " " + _messageView.ElementAt(i).DateCreated.ToString();
Grid.SetRow(Sender, ctr);
Grid.SetColumn(Sender, 0);
ctr++;
chatGrid.Children.Add(Message);
chatGrid.Children.Add(Greentail);
chatGrid.Children.Add(Sender);
//for (int i = 0; i < _messageView.Count; i++)
//
// if (_messageView.ElementAt(i).IsMe == true && (!_messageView.ElementAt(i).Message.ToString().Trim().Equals("")))
//
//
//
ctr = 0;
scrollView.ScrollToEnd();
有什么想法吗？谢谢
【问题讨论】：
【参考方案1】：大多数 UI 元素只能在 UI 线程中修改。由于您的事件处理程序显然是在不同的线程中调用的，因此您必须使用 Dispatcher 在 UI 线程中调用您的代码。
private void ConstructChatView(Boolean isChat)
Dispatcher.Invoke((Action)(() => chatGrid.Children.Clear()));
编辑：您还可以使用 anonymous method 将更多代码传递给 Invoke 调用：
private void ConstructChatView(Boolean isChat)
Dispatcher.Invoke((Action)(() =>
// more code here
));
当然，您也可以将一堆代码放在另一个方法中，然后将其传递给 Invoke 调用：
private void ConstructChatView(Boolean isChat)
Dispatcher.Invoke((Action)(() => ConstructChatViewInUI(isChat)));
private void ConstructChatViewInUI(Boolean isChat)
...
【讨论】：
感谢回复。但我正在尝试用代码创建我的整个网格。那么如何将我的整个代码包装到调用中呢？查看我编辑的帖子。 你也可以考虑使用异步的BeginInvoke来代替Invoke。 你能给我举个例子吗？我无法将我的代码包装到调用中。我试过这个。 Dispatcher.Invoke((Action)(() => //代码放在这里 ));以上是关于Grid.children.clear 线程错误 xmpp wpf的主要内容，如果未能解决你的问题，请参考以下文章