如何绑定列表计数中的WinForms标签吗? [英] How to bind a list count to a label in WinForms?
问题描述
我怎样才能绑定列表标签的数量。下面的代码开不得到与列表更新改变:
私人的IList<串GT;名单=新名单,LT;串>();
// ...
label1.DataBindings.Add(文本,list.Count,);
据马克Gravell对于这个问题,他有< A HREF =http://objectmix.com/csharp/388347-binding-formatstring-rendering-curly-braces-trick-bind-list-t-countproperty.html相对=nofollow>建议创建一个门面,它包装要绑定到label1.Text集合
我试图实现一个(的乐趣),并能得到结合的计数的工作
是一个门面,它包装集合结合。 CountList< T>
下面是完整的演示。
使用系统;
使用System.Collections.Generic;
使用System.ComponentModel;使用System.Windows.Forms的
;
命名空间TextBindingTest
{
公共部分Form1类:表格
{
私人只读CountList<串GT; _List =
新CountList<串GT(新的List<串GT; {A,B,C});
公共Form1中()
{
的InitializeComponent();
BindAll();
}
私人无效BindAll()
{
无功约束力=新的绑定(文本,_List,计数,真正的);
binding.Format + =(发件人,E)=> e.Value =的String.Format({0}项目,e.Value);
label1.DataBindings.Add(结合);
}
私人无效addToList_Click(对象发件人,EventArgs五)
{
_List.Add(A);
}
私人无效closeButton_Click(对象发件人,EventArgs五)
{
关闭();
}
}
公共类CountList< T> :INotifyPropertyChanged的
{
公共事件PropertyChangedEventHandler的PropertyChanged =委托{};
私人无效OnPropertyChanged(PropertyChangedEventArgs E)
{
VAR处理器=的PropertyChanged;
处理器(这一点,E);
}
私人的ICollection< T>清单{搞定;组; }
公众诠释计数{{返回List.Count; }}
公共CountList(ICollection的< T>清单)
{
=列出清单;
}
公共无效添加(T项目)
{
List.Add(项目);
OnPropertyChanged(新PropertyChangedEventArgs(计数));
}
}
}
How can I bind the count of a list to a label. The following code does't get updated with the list is changed:
private IList<string> list = new List<string>();
//...
label1.DataBindings.Add("Text", list.Count, "");
According to Marc Gravell for this problem, he has suggested to create a facade that wraps the collection you want to bind to label1.Text
I have tried to implement one (for fun) and was able to get binding to Count working.
CountList<T>
is a facade that wraps a collection to bind to.
Here is the full of the demo.
using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Windows.Forms;
namespace TextBindingTest
{
public partial class Form1 : Form
{
private readonly CountList<string> _List =
new CountList<string>(new List<string> { "a", "b", "c" });
public Form1()
{
InitializeComponent();
BindAll();
}
private void BindAll()
{
var binding = new Binding("Text", _List, "Count", true);
binding.Format += (sender, e) => e.Value = string.Format("{0} items", e.Value);
label1.DataBindings.Add(binding);
}
private void addToList_Click(object sender, EventArgs e)
{
_List.Add("a");
}
private void closeButton_Click(object sender, EventArgs e)
{
Close();
}
}
public class CountList<T> : INotifyPropertyChanged
{
public event PropertyChangedEventHandler PropertyChanged = delegate { };
private void OnPropertyChanged(PropertyChangedEventArgs e)
{
var handler = PropertyChanged;
handler(this, e);
}
private ICollection<T> List { get; set; }
public int Count { get { return List.Count; } }
public CountList(ICollection<T> list)
{
List = list;
}
public void Add(T item)
{
List.Add(item);
OnPropertyChanged(new PropertyChangedEventArgs("Count"));
}
}
}
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