关于数据绑定

[xxaabb]

TextBox控件绑定数据源，没有实现INotifyPropertyChanged接口的数据源照道理在UI界面上面输入，不能更改源数据值。
但我做实验却发现能改了。

实验：2个数据源，一个实现了INotifyPropertyChanged接口的class，一个是简单的class
2个TextBox分别被绑定在2个上述两个数据源

结果：都能通过TextBox输入改变源数据。

问题：为什么？
程序如下：

using System;
using System.Windows;
using System.Windows.Controls;
using System.Windows.Data;
using System.ComponentModel;

namespace 学习WPF数据绑定 {
    /// <summary>
    /// MainWindow.xaml 的交互逻辑
    /// </summary>
    public partial class MainWindow : Window {
        private NewTestData ntd;
        private OldTestData otd;
        
        public MainWindow() {
            InitializeComponent();

            ntd = new NewTestData() { txt = "新绑定" };
            otd = new OldTestData() { txt = "旧绑定" };

            //设定绑定
            Binding bind1 = new Binding();
            bind1.Source = ntd;
            bind1.Path = new PropertyPath("txt");
            textnew1.SetBinding(TextBox.TextProperty,bind1);

            Binding bind2 = new Binding();
            bind2.Source = otd;
            bind2.Path = new PropertyPath("txt");
            textold1.SetBinding(TextBox.TextProperty, bind2);

        }


        private void Button_Click(object sender, RoutedEventArgs e) {
            textnew2.Text = ntd.txt;
            textold2.Text = otd.txt;

        }
    }

    //=====数据源class NewTestData
    public class NewTestData:INotifyPropertyChanged {
        private string _txt;
        public string txt {
            get { return _txt; }
            set { 
                _txt = value;
                if (PropertyChanged != null) {
                    PropertyChanged.Invoke(this, new PropertyChangedEventArgs("txt"));
                }
            } 
        }
        public event PropertyChangedEventHandler PropertyChanged;
    }
    //=====数据源class OldTestData
    public class OldTestData {
        public string txt { get; set; }
    }
}

-----xmal

<Window x:Class="学习WPF数据绑定.MainWindow"
        xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
        xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
        Title="MainWindow" Height="150" Width="200">
    <Grid>
        <Grid.RowDefinitions>
            <RowDefinition Height="35*"/>
            <RowDefinition Height="35*"/>
            <RowDefinition Height="48*"/>
        </Grid.RowDefinitions>
        <TextBlock Margin="10,5,163,10" Text="新" Grid.Row="0"/>
        <TextBox Name="textnew1" Margin="34,5,87,6" Grid.Row="0"/>
        <TextBox Name="textnew2" Margin="110,5,10,6" Grid.Row="0"/>

        <TextBlock Margin="10,5,163,10" Text="旧" Grid.Row="1"/>
        <TextBox Name="textold1" Margin="34,5,87,6" Grid.Row="1"/>
        <TextBox Name="textold2" Margin="110,5,10,6" Grid.Row="1"/>

        <Button Content="改变" Grid.Row="2" Margin="56,10" Click="Button_Click"/>
    </Grid>
</Window>

[Forty2]

因为你是直接给TextBox赋值，而不是改变数据源。 把Button_Click作如下改动就可以看到效果了：

private void Button_Click(object sender, RoutedEventArgs e)
{
    //textnew2.Text = ntd.txt;
    //textold2.Text = otd.txt;
    ntd.txt = "hello";
    otd.txt = "world";
}

[xxx_jiujiamei]

关于TextBox控件绑定数据源修改示例 //绑定TextBox控件显示数据库数据 protected void Page_Load(object sender, EventArgs e) { if (!IsPostBack) { try { SqlConnection mycon = new SqlConnection(ConfigurationManager.AppSettings["conStr"]); mycon.Open(); DataSet mydataset = new DataSet(); SqlDataAdapter mydataadapter = new SqlDataAdapter("select * from tb_Admin where id=" + Request["id"],mycon); mydataadapter.Fill(mydataset, "tb_Admin"); DataRowView rowview = mydataset.Tables["tb_Admin"].DefaultView[0]; this.txtName.Text = Convert.ToString(rowview["UserName"]); this.txtPwd.Text = Convert.ToString(rowview["PassWord"]); this.ddlSex.SelectedValue = Convert.ToString(rowview["Sex"]); this.txtRealName.Text = Convert.ToString(rowview["ReallyName"]); this.txtBirthday.Text = Convert.ToString(rowview mycon.Close(); } catch (Exception ex) { Response.Write(ex.Message); }//codego.net/15/1/1/ } } //修改TextBox控件数据 protected void btnUpdate_Click(object sender, EventArgs e) { try { SqlData da = new SqlData(); string P_str_Com = "update tb_Admin set UserName='" + this.txtName.Text + "',PassWord='" + this.txtOKpwd.Text + "'" + ",Sex='" + this.ddlSex.SelectedValue + "',ReallyName='" + this.txtRealName.Text + "'" + " where ID='" + Request["ID"] + "'"; bool add = da.ExceSQL(P_str_Com); if (add == true) { Response.Write("<script language=javascript>alert('修改信息成功!');location='AdminManage.aspx'</script>"); } else { Response.Write("<script language=javascript>alert('修改信息失败！');location='javascript:history.go(-1)'</script>"); } } catch (Exception ex) { Response.Write(ex.Message); } }

[娃都会打酱油了]

Binding本身已经实现了相关通知接口……

[exception92]

你不要使用 Binding ，你直接赋值，它永远都不会 通知。