我的静态模型/属性没有绑定到我的UI [英] My static Model/Property is not binding to my UI

问题描述

新的WPF。

我试图将我的模型绑定到我的UI。所以，当我的用户操作中的属性被更改时，我希望字段在我的UI上发生更新。

I am trying to bind my Model to my UI. So, when the Property is changed during my User actions I want the field to update whereever it occurs on my UI.

这是我的模型：

namespace WpfApplication1
{
    public class model2
    {
        private static string myField2;

        public static string MyField2
        {

            get { return myField2; }
            set { myField2 = value; }
        }
    }
}

我的标记： p>

My Markup:

<Window x:Class="WpfApplication1.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:WpfApplication1"       
        mc:Ignorable="d"
        Title="MainWindow" Height="350" Width="525">
    <Window.Resources>
        <local:model2 x:Key="mymodel"/>
    </Window.Resources>
    <Grid>
        <StackPanel Orientation="Vertical">
            <TextBlock Text="{Binding Source={StaticResource ResourceKey=mymodel}, Path=MyField2}"></TextBlock>     
            <Button Content="static test!" Click="Button_Click_1" />
        </StackPanel>
    </Grid>
</Window>

我的代码：

using System.Windows;

namespace WpfApplication1
{
    public partial class MainWindow : Window
    {
        public MainWindow()
        {
            InitializeComponent();
        }

        private void Button_Click_1(object sender, RoutedEventArgs e)
        {
            model2.MyField2 = "static!";
        }
    }
}

UI上的字段不要更改？

The field on the UI does not change?

推荐答案

您需要通知UI更改，以便可以使用新值更新。

You need to notify changes to the UI so it can update with new values.

在您的情况下，您想要通知静态属性的更改，因此您需要一个静态事件。问题是INotifyPropertyChanged接口需要一个成员事件，所以你不可能这样。

In your case you want to notify static properties of changes so you would need a static event. The problem is the INotifyPropertyChanged interface needs a member event so you won't be able to go that way.

你最好的方法是实现Singleton模式：

You best shot is to implement the Singleton pattern:

namespace WpfApplication1
{
    public class model2 : INotifyPropertyChanged
    {
        //private ctor so you need to use the Instance prop
        private model2() {}

        private string myField2;

        public string MyField2
        {

            get { return myField2; }
            set { 
                myField2 = value; 
                OnPropertyChanged("MyField2");
            }
        }

        private static model2 _instance;

        public static model2 Instance {
            get {return _instance ?? (_instance = new model2();)}
        }

        public event PropertyChangedEventHandler PropertyChanged;

        protected virtual void OnPropertyChanged(string propertyName) {
            var handler = PropertyChanged;
            if (handler != null) handler(this, new PropertyChangedEventArgs(propertyName));
        }
    }
}

然后让你的属性成员属性并绑定如下：

And then make your property a member property and bind like this:

<Window x:Class="WpfApplication1.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:WpfApplication1"       
        mc:Ignorable="d"
        Title="MainWindow" Height="350" Width="525">
    <Window.Resources>
        <local:model2 x:Key="mymodel"/>
    </Window.Resources>
    <Grid>
        <StackPanel Orientation="Vertical">
            <TextBlock Text="{Binding Source={x:Static local:model2.Instance}, Path=MyField2}"/>  
            <Button Content="static test!" Click="Button_Click_1" />
        </StackPanel>
    </Grid>
</Window>

代码背后：

using System.Windows;

namespace WpfApplication1
{
    public partial class MainWindow : Window
    {
        public MainWindow()
        {
            InitializeComponent();
        }

        private void Button_Click_1(object sender, RoutedEventArgs e)
        {
            model2.Instance.MyField2 = "static!";
        }
    }
}

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