WPF入门笔记 三 数据绑定

1.元素绑定

<Window x:Class="demo.MainWindow"
        xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
        xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
        xmlns:d="http://schemas.microsoft.com/expression/blend/2008"
        xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"
        xmlns:local="clr-namespace:demo"
        mc:Ignorable="d"
        Title="MainWindow" Height="450" Width="800" Loaded="Window_Loaded" MouseLeftButtonDown="Window_MouseLeftButtonDown">
    
    <Grid>
        <StackPanel>
            <Slider x:Name="sd" Width="200"/>
            <TextBox Text="{Binding ElementName=sd, Path=Value}"/>
        </StackPanel>
    </Grid>
    
    
</Window>

2.资源绑定

<Window x:Class="demo.MainWindow"
        xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
        xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
        xmlns:d="http://schemas.microsoft.com/expression/blend/2008"
        xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"
        xmlns:local="clr-namespace:demo"
        mc:Ignorable="d"
        Title="MainWindow" Height="450" Width="800" Loaded="Window_Loaded" MouseLeftButtonDown="Window_MouseLeftButtonDown">

    <Window.Resources>
        <TextBox x:Key="txt" Text="hello"/>
    </Window.Resources>
    
    <Grid>

        <StackPanel>
            <TextBox Text="{Binding Source={StaticResource txt}, Path=Text}"/>
        </StackPanel>
    </Grid>
    
    
</Window>

3.绑定属性（第一种）

1.定义一个显示控件

  <Grid>

        <StackPanel>
            <TextBox x:Name="txt" Text="{Binding MyVar, FallbackValue='Not Found'}"/>
        </StackPanel>
    </Grid>
    

2.先绑定数据上下文

  public partial class MainWindow : Window
    {


        public MainWindow()
        {
            InitializeComponent();
            txt.DataContext = new DataSource();
        }

    }

3.定义一个数据类

 public class DataSource:INotifyPropertyChanged
    {

        public DataSource()
        {
            Task.Run(async () =>
            {
                await Task.Delay(3000);
                MyVar = "3333";
            });
        }


        private string _myVar = "2222";

        public string MyVar
        {
            get { return _myVar; }
            set { _myVar = value;
                OnPropertychanged("MyVar");
            }
        }

        public event PropertyChangedEventHandler PropertyChanged;

        //通知UI更新
        protected void OnPropertychanged(string properName)
        {
            if (PropertyChanged != null)
            {
                PropertyChanged(this, new PropertyChangedEventArgs(properName));
            }

        }
    }

    

4.绑定属性（第二种）

使用MVVM框架
1.安装 MVVMLight框架

2.编写绑定代码

//1.引用框架
using GalaSoft.MvvmLight;
using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Linq;
using System.Text;
using System.Threading.Tasks;

namespace demo
{
//2.继承 ViewModelBase
    public class DataSource:ViewModelBase
    {

        public DataSource()
        {
            Task.Run(async () =>
            {
                await Task.Delay(3000);
                MyVar = "3333";
                MyVar1 = "Hello Hello";
            });
        }


        private string _myVar = "2222";

        public string MyVar
        {
            get { return _myVar; }
            set
            { _myVar = value;
            //3.调用通知
                RaisePropertyChanged();

            }
        }


        private string myVar1="Hello";

        public string MyVar1
        {
            get { return myVar1; }
            set 
            { myVar1 = value;

                RaisePropertyChanged();
            }
        }


    }

    
}

标签：入门,绑定,System,myVar,using,WPF,public,string
来源： https://blog.csdn.net/jinlin_0/article/details/110421140