标签:cdata red his mes name att items 对象 abstract
WPF 错误:Must create DependencySource on same Thread as the DependencyObject
先看数据模型类吧
public class MessageInfo
{
public string Message { get; set; }
public FontWeight FontWeight { get; set; }
public SolidColorBrush Foreground { get; set; }
}
class M_LoadBKCData : INotifyPropertyChanged
{
public event PropertyChangedEventHandler PropertyChanged;
protected void RaisePropertyChanged(string propertyName)
{
if (this.PropertyChanged != null) this.PropertyChanged(this, new PropertyChangedEventArgs(propertyName));
}
private ObservableCollection<MessageInfo> _Message = new ObservableCollection<MessageInfo>();
public ObservableCollection<MessageInfo> Message
{
get { return _Message; }
set
{
if (_Message != value)
{
_Message = value;
this.RaisePropertyChanged("Message");
}
}
}
}
然后看模型绑定到的WPF XAML 代码
<Grid x:Name="Grid1">
<ItemsControl FontSize="14" Foreground="Gray" Visibility="Visible" Grid.Row="1" ItemsSource="{Binding Message}">
<ItemsControl.ItemTemplate>
<DataTemplate>
<Label x:Name="PART_Label" FontWeight="{Binding FontWeight}" Foreground="{Binding Foreground}"
Content="{Binding Message}" Margin="0,2"/>
<DataTemplate.Triggers>
<DataTrigger Binding="{Binding FontWeight}" Value="{x:Static FontWeights.Normal}">
<Setter Property="Padding" Value="10,0,0,0" TargetName="PART_Label"/>
</DataTrigger>
</DataTemplate.Triggers>
</DataTemplate>
</ItemsControl.ItemTemplate>
</ItemsControl>
</Grid>
后台代码大概如下
M_LoadBKCData Model = new M_LoadBKCData();
Grid1.DataContext = Model;
Model.Message.Add(new MessageInfo() {
Message = "第一条消息", FontWeight = FontWeights.Bold, Foreground = new SolidColorBrush(Colors.Red)
}); //这条数据会再界面显示
然后开启一个线程,如下代码将会报错
Task.Factory.StartNew(() =>
{
Thread.Sleep(5000);
SolidColorBrush foreground =new SolidColorBrush(Colors.Black);
MessageInfo msgInfo = new MessageInfo()
{
Message = "下一条消息",
FontWeight = FontWeights.Normal,
Foreground = foreground
};
Grid1.Dispatcher.Invoke(() => {
Model.Message.Add(msgInfo);
});
});
报错如下图
报错原因:SolidColorBrush属于WPF对象,当前情况是在另外的线程创建的,导致出现问题,需要修改为如下
Task.Factory.StartNew(() =>
{
Thread.Sleep(5000);
Grid1.Dispatcher.Invoke(() => {
SolidColorBrush foreground = new SolidColorBrush(Colors.Black);
MessageInfo msgInfo = new MessageInfo()
{
Message = "下一条消息",
FontWeight = FontWeights.Normal,
Foreground = foreground
};
Model.Message.Add(msgInfo);
});
});
如果时用了MVVM模式, Model层有INotify类型的 属性, 若果是WPF的类相关的,需要特别注意下,
不能在其他线程中进行实例化,看下SolidColorBrush的定义,继承DependencyObject
public sealed class SolidColorBrush : Brush { }
public abstract class Brush : Animatable, IFormattable, IResource { }
public abstract class Animatable : Freezable, IAnimatable, IResource { }
public abstract class Freezable : DependencyObject, ISealable { }
Must create DependencySource on same Thread as the DependencyObject
标签:cdata red his mes name att items 对象 abstract
原文地址:https://www.cnblogs.com/wandia/p/14811560.html