Binding - KeenLeung－IT工程師數位筆記本

文章出處

1)數據源

添加一個Student類：

(Binding是一種自動機制，當值變化后屬性要有能力通知Binding，讓Binding把變化傳遞給UI元素。方法是在屬性set語句中激發一個PropertyChanged事件。這個事件不用我們聲明，我們要做到的是讓作為數據源的類實現System.ComponentModel名稱空間中的INotifyPropertyChanged接口。當為Binding設置了數據源后，Binding就會自動監聽來自這個接口的PropertyChanged事件。)

using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Linq;
using System.Text;

namespace TestBinding
{
    class Student:INotifyPropertyChanged//實現這個接口，讓Binding自動監聽
    {
        public event PropertyChangedEventHandler PropertyChanged;

        private string name;

        public string Name
        {
            get { return name; }
            set {
                name = value;
                //激發事件
                if (this.PropertyChanged != null)
                {
                    this.PropertyChanged.Invoke(this, new PropertyChangedEventArgs("Name"));
                }
            }
        }
    }
}

或者：

using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Linq;
using System.Text;

namespace TestBinding
{
    class Student:INotifyPropertyChanged//實現這個接口，讓Binding自動監聽
    {
        public event PropertyChangedEventHandler PropertyChanged;

        private string name;

        public string Name
        {
            get { return name; }
            set {
                name = value;
                //激發事件
                PropertyChangedEventHandler handler = PropertyChanged;
                if (this.PropertyChanged != null)
                {
                    //this.PropertyChanged.Invoke(this, new PropertyChangedEventArgs("Name"));
                    handler(this, new PropertyChangedEventArgs("Name"));
                }
            }
        }
    }
}

2)編寫前臺代碼：

XAML:

<Window x:Class="TestBinding.MainWindow"
        xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
        xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
        Title="MainWindow" Height="110" Width="300">
    <Grid>
        <StackPanel>
            <TextBox x:Name="textBoxName" BorderBrush="Black" Margin="5"></TextBox>
            <Button Content="Add Age" Margin="5" Click="Button_Click"></Button>
        </StackPanel>
    </Grid>
</Window>

3)使用Binding把數據源和UI元素連接起來

C#:

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Windows;
using System.Windows.Controls;
using System.Windows.Data;
using System.Windows.Documents;
using System.Windows.Input;
using System.Windows.Media;
using System.Windows.Media.Imaging;
using System.Windows.Navigation;
using System.Windows.Shapes;

namespace TestBinding
{
    /// <summary>
    /// MainWindow.xaml 的交互邏輯
    /// </summary>
    public partial class MainWindow : Window
    {
        Student stu;
        public MainWindow()
        {
            InitializeComponent();

            /*
            //準備數據源
            stu = new Student();

            //準備Binding
            Binding binding = new Binding();
            binding.Source = stu;
            binding.Path = new PropertyPath("Name");//為Binding指定訪問路徑

            //使用Binding連接數據源與Binding目標
            BindingOperations.SetBinding(textBoxName, TextBox.TextProperty, binding);
            */

            //以上三合一的做法：
            this.textBoxName.SetBinding(TextBox.TextProperty, new Binding("Name") { Source = stu = new Student() });
            //this.textBoxName.SetBinding(TextBox.TextProperty, new Binding() { Source = stu = new Student(),Path=new PropertyPath("Name") });
        }

        private void Button_Click(object sender, RoutedEventArgs e)
        {
            stu.Name += "Name";
        }
    }
}