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C# 控件之数据绑定

增加一个委托方法,可以实现后台多线程直接更新UI界面的值,利用了控件的DataBindings,以及 INotifyPropertyChanged接口和事件委托机制。

如果只是通过INotifyPropertyChanged,可在前台单独更新界面,无法通过多线程进行界面值更新。 这可以利用委托和事件的机制,在UI加入事件,通过invoke进行委托调用 ,从而可以实现 。

另外一种方法是设置窗体的CheckForIllegalCrossThreadCalls =false,但该操作方法不是微软建议使用的多线程界面更新的方法。

新建一个winform程序,然后添加两个textbox 和一个button ,写入以下代码 。

using System;
using System.ComponentModel;
using System.Threading;
using System.Windows.Forms;

namespace TestFrom
{
    public partial class Form1 : Form
    {
        public Form1()
        {
            InitializeComponent();
        }

        private TestBind model = new TestBind();
        private void Form1_Load(object sender, EventArgs e)
        {
            //  CheckForIllegalCrossThreadCalls = false; 
            model.NoticeHandler += new PropertyNoticeHandler(PropertyNoticeHandler);
            Binding bind1 = new Binding("Text", model, "Value");
            Binding bind2 = new Binding("Text", model, "Name");
            textBox1.DataBindings.Add(bind1);
            textBox2.DataBindings.Add(bind2);
        }

        private void PropertyNoticeHandler(object handle, string proName)
        {
            try
            {
                BeginInvoke(
                    new Action(() => model.Bind(proName)));
            }
            catch
            {
            }
        }

        private void button1_Click(object sender, EventArgs e)
        {
            new Thread(() =>
            {
                while (true)
                {
                    model.Value++;
                    model.Name = Guid.NewGuid().ToString();


                    Thread.Sleep(1000);
                }
            })
            {
                IsBackground = true
            }.Start();
        }
        public event PropertyChangedEventHandler PropertyChanged;
    }

    public class TestBind : INotifyPropertyChanged
    {
        private string name;

        public string Name
        {
            get { return name; }
            set
            {
                name = value;
                SendChangeInfo("Name");
            }
        }

        private int value;

        public int Value
        {
            get { return value; }
            set
            {
                this.value = value;
                SendChangeInfo("Value");
            }
        }

        private void SendChangeInfo(string propertyName)
        {
            if (NoticeHandler != null)
            {
                NoticeHandler(this, propertyName);
            }
        }

        public void Bind(string propertyName)
        {
            if (PropertyChanged != null)
            {
                PropertyChanged(this, new PropertyChangedEventArgs(propertyName));
            }

        }
        public event PropertyNoticeHandler NoticeHandler;
        public event PropertyChangedEventHandler PropertyChanged;
    }

    public delegate void PropertyNoticeHandler(object handle, string proName);
}

 

posted on 2017-04-13 15:00  莲藕  阅读(1508)  评论(0编辑  收藏  举报