WPF 精修篇 数据绑定 更新通知

Posted 2021-03-21 lonelyxmas

原文:WPF 精修篇 数据绑定 更新通知

开始更新一点有意思的了

首先 数据绑定  其中之一 Element 绑定

看例子

<Window x:Class="WpfApplication20.MainWindow"
        xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
        xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
        Title="MainWindow" Height="156.383" Width="246.489" x:Name="MWindow">
    <Grid>
        <TextBox HorizontalAlignment="Left" Height="23" Margin="30,48,0,0" TextWrapping="Wrap" VerticalAlignment="Top" Width="120" Text="{Binding ElementName=MWindow,Path=PresonName}"/>
        <TextBlock HorizontalAlignment="Left" Margin="30,16,0,0" TextWrapping="Wrap" VerticalAlignment="Top" Width="42" Text="部门："/>
        <Button Content="提交" HorizontalAlignment="Left" Margin="30,85,0,0" VerticalAlignment="Top" Width="75" Click="Button_Click"/>
        <Button Content="重置" HorizontalAlignment="Left" Margin="127,85,0,0" VerticalAlignment="Top" Width="75" Click="Button_Click_1"/>
        <TextBlock HorizontalAlignment="Left" Margin="85,16,0,0" TextWrapping="Wrap"  VerticalAlignment="Top" Text="{Binding ElementName=MWindow,Path=Department}"/>
 
    </Grid>
</Window>

   public partial class MainWindow : Window,INotifyPropertyChanged
    {
        public MainWindow()
        {
            InitializeComponent();
        }
 
        private string department;
 
        public string Department 
        {
            get { return "软件开发"; }
       
        }
        private string presonName;
      
        public string PresonName
        {
            get { return presonName; }
            set { presonName = value;
            OnPropertyChanged("PresonName");
            }
        }
        private void Button_Click(object sender, RoutedEventArgs e)
        {
            MessageBox.Show("Hi," + PresonName);
        }
 
        private void Button_Click_1(object sender, RoutedEventArgs e)
        {
            PresonName = "";
        }
 
        #region INotifyPropertyChanged 成员
 
        public event PropertyChangedEventHandler PropertyChanged;
        public void OnPropertyChanged(string name) 
        {
            if(PropertyChanged!=null){
            PropertyChanged.Invoke(this,new PropertyChangedEventArgs(name));
            }
        }
 
        #endregion
    }

我们在这个例子里有俩个操作

一个是数据绑定

一个是数据通知

绑定 是用Element 指定window 窗体 因为 创建属性以后 window 窗体就有这个属性 通过名字.属性的方式

通知 需要继承 INotifyPropertyChanged

实现接口方法

  public event PropertyChangedEventHandler PropertyChanged;

    public void OnPropertyChanged(string name) 
        {
            if(PropertyChanged!=null){
            PropertyChanged.Invoke(this,new PropertyChangedEventArgs(name));
            }
        }

在需要通知的属性下面  加上

OnPropertyChanged（“”属性名“”）;

就可以起到通知作用