这里的目标是使用 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字,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。