数据绑定的DataGridView和名单，其中的;＆GT;与BindingSource的 [英] DataBinding of DataGridView and List<> with BindingSource

问题描述

我试图找出如何用数据的BindingSource 的结合应该是工作 我希望有一个的DataGridView 来与一个名单，其中的内容填充;＆GT; 在列表的更新。

我可以看到列表成长和验证当我检查调试它充满。我以为的BindingSource 将触发事件的列表被改变时。但没有可用的被激发。我如何成为通知当底层表更改？

我按照说明进行操作，并具有以下测试code：

 数据D;
    BindingSource的BS;

    公共Form1中（）
    {
        的InitializeComponent（）;
        BS =新的BindingSource（）;
        D =新的Data（）;
    }

    私人无效Form1_Load的（对象发件人，EventArgs的）
    {
        bs.DataSourceChanged + =新的EventHandler（bs_DataSourceChanged）;
        bs.ListChanged + =新ListChangedEventHandler（bs_ListChanged）;
        bs.DataMemberChanged + =新的EventHandler（bs_DataMemberChanged）;
        bs.CurrentChanged + =新的EventHandler（bs_CurrentChanged）;
        bs.CurrentItemChanged + =新的EventHandler（bs_CurrentItemChanged）;

        bs.DataSource = d.list;
        dataGridView1.DataSource = BS;
    }
    // ......都赶上在VS.一个破发点的处理方法

    私人无效的button1_Click（对象发件人，EventArgs的）
    {
        d.addOneItem（）;
    }
 

解决方案

名单，其中，T＆GT; 不支持更改事件; 的BindingList＆LT; T＆GT; 将是一个很好的替代品，以支持此方案，并且它也支持项目级的变化事件，如果你键入 T 工具 INotifyPropertyChanged的。

在3.0以上，也有<一个href="http://msdn.microsoft.com/en-us/library/ms668604.aspx"><$c$c>ObservableCollection<T>,这同样起到的BindingList＆LT; T＆GT; 。这一切都归结到接口，如 IBindingList的， IBindingListView 等。

---

从意见;添加一个2.0 / 3.0例如查找到的BindingList＆LT; T＆GT; ：

 公共类MyBindingList＆LT; T＆GT; ：的BindingList＆LT; T＆GT;
{
    公共找不到（predicate＆LT; T＆GT; predicate）
    {
        如果（predicate == NULL）抛出新ArgumentNullException（predicate）;
        的foreach（在这件T项）
        {
            如果（predicate（项目））收益项目;
        }
        返回默认（T）;
    }
}
 

请注意，在3.5（或.NET 2.0 / 3.0 LINQBridge和C＃3.0），则不需要此 - 任何LINQ扩展方法会做同样的事情

I'm trying to figure out how data binding with BindingSource is supposed to work I want a DataGridView to be populated with the content of a List<> upon update of the list.

I can see the List grow and verify it's being filled when I check the debugger. I thought the BindingSource would fire an event when the List is changed. But none of the available is fired. How do I become notified when the underlying list is changed?

I follow the instructions and have the following test code:

    Data d;
    BindingSource bs;

    public Form1()
    {
        InitializeComponent();
        bs = new BindingSource();
        d = new Data();
    }

    private void Form1_Load(object sender, EventArgs e)
    {
        bs.DataSourceChanged += new EventHandler(bs_DataSourceChanged);
        bs.ListChanged += new ListChangedEventHandler(bs_ListChanged);
        bs.DataMemberChanged += new EventHandler(bs_DataMemberChanged);
        bs.CurrentChanged += new EventHandler(bs_CurrentChanged);
        bs.CurrentItemChanged += new EventHandler(bs_CurrentItemChanged);

        bs.DataSource = d.list;
        dataGridView1.DataSource = bs;
    }
    // ... all the handling methods caught with a break point in VS.

    private void button1_Click(object sender, EventArgs e)
    {
        d.addOneItem();
    }

解决方案

List<T> doesn't support change events; BindingList<T> would be a good substitute to support this scenario, and it also supports item-level change events if your type T implements INotifyPropertyChanged.

In 3.0 and above, there is also ObservableCollection<T>, which acts similarly to BindingList<T>. It all comes down to interfaces such as IBindingList, IBindingListView, etc.

---

From comments; for a 2.0/3.0 example of adding a Find to BindingList<T>:

public class MyBindingList<T> : BindingList<T>
{
    public T Find(Predicate<T> predicate)
    {
        if (predicate == null) throw new ArgumentNullException("predicate");
        foreach (T item in this)
        {
            if (predicate(item)) return item;
        }
        return default(T);
    }
}

Note that in 3.5 (or in .NET 2.0/3.0 with LINQBridge and C# 3.0) you don't need this - any of the LINQ extension methods would do the same thing.

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