通过绑定源将文本框绑定到对象属性不刷新

Question

这里的目的是使用 BindingSource + Object 作为 DataSource 和 TextBox 来显示对象的属性值。

我面临的问题是 TextBox 没有反映底层对象的属性值变化。

正如中国人所说的一张图片等于一千个单词，所以下面的演示代码演示了我面临的问题。

using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using System.Windows.Forms;
using System.Runtime.CompilerServices;


namespace TextBoxDataSourceBindingDemo
{


    public partial class Form1 : Form
    {
        private BindingSource dsSource;
        private BindingDemoClass bDemoClass;
        public Form1()
        {
            InitializeComponent();
            bDemoClass = new BindingDemoClass();
            dsSource = new BindingSource();

            bDemoClass.BindingName = "DemoBinding";
            this.textBox1.DataBindings.Add(new Binding("Text", dsSource, "BindingName",true,DataSourceUpdateMode.OnPropertyChanged));
        }

        private void btnAssignDataSource_Click(object sender, EventArgs e)
        {
           //Setting the datasource is not enough to 
           //update the related textbox
           //refresh must be explicity called ?
           dsSource.DataSource = bDemoClass;
           dsSource.ResetBindings(true);
        }

        private void btnChangePropertyValue_Click(object sender, EventArgs e)
        {
            //Here after setting the property value
            //the textbox should be update with the new value; correct ?
            bDemoClass.BindingName = "DemoBinding2";
        }
    }
    //Demo class used as datasource  
    public class BindingDemoClass : INotifyPropertyChanged
    {
        private string _BindingName = String.Empty;

        public string BindingName
        {
            get { return _BindingName; }
            set
            {
                if (!String.Equals(_BindingName, value))
                {
                    _BindingName = value;
                    NotifyPropertyChanged();
                }
            }
        }

        private void NotifyPropertyChanged([CallerMemberName] String propertyName = "")
        {
            if (PropertyChanged != null)
            {
                PropertyChanged(this, new PropertyChangedEventArgs(propertyName));
            }
        }


        #region INotifyPropertyChanged Members

        public event PropertyChangedEventHandler PropertyChanged;

        #endregion
    }
}

因此，当单击 btnAssignDataSource 按钮时，文本框会更新。 我希望当绑定属性更改（btnChangePropertyValue）时，更改将反映到文本框。

Answer 1

你试过这个 this.textBox1.DataBindings.Add("Text", dsSource, "BindingName");