如何正确地从后端线程更新数据绑定的datagridview [英] How do you correctly update a databound datagridview from a background thread

问题描述

我有一个自定义对象实现INotifyPropertyChanged。我收集了这些对象，其中集合基于BindingList
我已经为集合创建了绑定源，并设置了bindingsource和datagridview的数据源。

除了我需要从后台线程更新自定义对象的属性外，一切都很好用。当我这样做，我得到以下错误：

BindingSource不能是自己的数据源。不要将DataSource和DataMember属性设置为返回BindingSource的值

我发现以下帖子似乎有我的确切问题（和解决方案？），但我不能弄清楚。

http://social.msdn.microsoft.com/forums/en-US/winformsdatacontrols/线程/ 3566f7c7-eb47-422e-ab09-9549a18da360 /

我创建并初始化了每个帖子中的操作变量我的业务对象，然后我将两个事件函数放入我的收集类。这个编译正确，但在运行时无一例外。

我看到很多帖子说使用Invoke / Begin Invoke，但是我没有在UI上调用任何函数，只是更新业务对象，所以我不知道我会在哪里调用调用。一个限制：我希望业务对象不知道谁正在显示它（因为有多个消费者），所以将GUI引用发送到业务对象，以便我以后可以使用这些引用调用invoke不是一个选项。

解决方案

我在一个论坛上发现这个类。只需使用这个而不是BindingList

  using System; 
使用System.Collections.Generic; 
使用System.Linq; 
使用System.Text; 
 
使用System.ComponentModel; 
使用System.Threading; 
 
命名空间实用程序
 {
 public class ThreadedBindingList< T> ：BindingList< T> 
 {
 SynchronizationContext ctx = SynchronizationContext.Current; 
 
 protected override void OnAddingNew（AddingNewEventArgs e）
 {
 
 if（ctx == null）
 {
 BaseAddingNew（e）; 
} 
 else 
 {
 ctx.Send（委托
 {
 BaseAddingNew（e）; 
}，null）; 
} 
} 
 void BaseAddingNew（AddingNewEventArgs e）
 {
 base.OnAddingNew（e）; 
} 
 protected override void OnListChanged（ListChangedEventArgs e）
 {
 // SynchronizationContext ctx = SynchronizationContext.Current; 
 if（ctx == null）
 {
 BaseListChanged（e）; 
} 
 else 
 {
 ctx.Send（委托
 {
 BaseListChanged（e）; 
}，null）; 
} 
} 
 void BaseListChanged（ListChangedEventArgs e）
 {
 base.OnListChanged（e）; 
} 
} 
} 
  

I have a custom object that implements INotifyPropertyChanged. I have a collection of these objects where the collection is based on BindingList I have created a binding source for the collection, and set the datasources of the bindingsource and datagridview.

Everything works great, except I need to update properties on the custom object from background threads. when I do so, I get the following error :

BindingSource cannot be its own data source. Do not set the DataSource and DataMember properties to values that refere back to BindingSource

I found the following post that seems to have my exact problem (and solution?) but I cannot quite figure it out.

http://social.msdn.microsoft.com/forums/en-US/winformsdatacontrols/thread/3566f7c7-eb47-422e-ab09-9549a18da360/

I created and initialized the oper variables per the post in my business object, and then I put the two event functions into my collection class. This compiled correctly, but hangs without exception when run.

I have seen many posts saying to use Invoke/Begin Invoke, but I am not calling any functions on the UI, just updating business objects, so I am not sure where I would put the invoke calls.

One restriction : I want the business object to remain unaware of who is displaying it (as there are multiple consumers) so sending in GUI references into the business object so that I am later able to call invoke using those references is not an option.

解决方案

I found this class in a forum that works. Just use this instead of BindingList

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;

using System.ComponentModel;
using System.Threading;

namespace Utility
{
    public class ThreadedBindingList<T> : BindingList<T>
    {
        SynchronizationContext ctx = SynchronizationContext.Current;

        protected override void OnAddingNew(AddingNewEventArgs e)
        {

            if (ctx == null)
            {
                BaseAddingNew(e);
            }
            else
            {
                ctx.Send(delegate
                {
                    BaseAddingNew(e);
                }, null);
            }
        }
        void BaseAddingNew(AddingNewEventArgs e)
        {
            base.OnAddingNew(e);
        }
        protected override void OnListChanged(ListChangedEventArgs e)
        {
           // SynchronizationContext ctx = SynchronizationContext.Current;
            if (ctx == null)
            {
                BaseListChanged(e);
            }
            else
            {
                ctx.Send(delegate
                {
                    BaseListChanged(e);
                }, null);
            }
        }
        void BaseListChanged(ListChangedEventArgs e)
        {
            base.OnListChanged(e);
        }
    } 
}

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