c# - Prism 6 DelegateCommand Observes属性代码

Question

嗨，你好，我是 WPF 和 MVVM 设计模式的新手，我从 PRISM 的 BRIAN LAGUNAS 爵士的博客和视频中学到了很多东西..但只想问一个菜鸟问题..有什么问题我的代码对我有用...非常感谢任何帮助。这是我的代码:

我的 View 模型

public class Person : BindableBase
{
    private myPErson _MyPerson;
    public myPErson MyPerson
    {
        get { return _MyPerson; }
        set
        {
            SetProperty(ref _MyPerson, value);
        }
    }

    public Person()
    {
        _MyPerson = new myPErson();
        updateCommand = new DelegateCommand(Execute, CanExecute).ObservesProperty(() => MyPerson.FirstName).ObservesProperty(() => MyPerson.Lastname);

    //    updateCommand = new DelegateCommand(Execute).ObservesCanExecute((p) => CanExecute); /// JUST WANNA TRY THIS BUT DUNNO HOW
    }

    private bool CanExecute()
    {
        return !String.IsNullOrWhiteSpace(MyPerson.FirstName) && !String.IsNullOrWhiteSpace(MyPerson.Lastname);
    }

    private void Execute()
    {
        MessageBox.Show("HOLA");
    }

    public DelegateCommand updateCommand { get; set; }
}

我的模型

声明到另一个类文件

public class myPErson : BindableBase
{
    private string _firstName;
    public string FirstName
    {
        get { return _firstName; }
        set
        {
            SetProperty(ref _firstName, value);
        }
    }

    private string _lastname;
    public string Lastname
    {
        get { return _lastname; }
        set
        {
            SetProperty(ref _lastname, value);
        }
    }
}

查看Xaml代码

<Window x:Class="Prism6Test.Views.MainWindow"
        xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
        xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
        xmlns:myVM="clr-namespace:Prism6Test.ViewModel"
        Title="MainWindow" Height="350" Width="525">
    <Window.Resources>
        <myVM:Person x:Key="mainVM"/>
    </Window.Resources>
<Grid DataContext="{StaticResource mainVM}">
        <TextBox HorizontalAlignment="Left" Height="23" Margin="217,103,0,0" TextWrapping="Wrap" Text="{Binding MyPerson.FirstName,UpdateSourceTrigger=PropertyChanged}" VerticalAlignment="Top" Width="120"/>
        <TextBox HorizontalAlignment="Left" Height="23" Margin="217,131,0,0" TextWrapping="Wrap" Text="{Binding MyPerson.Lastname,UpdateSourceTrigger=PropertyChanged}" VerticalAlignment="Top" Width="120"/>
        <Button Content="Button" Command="{Binding updateCommand}" HorizontalAlignment="Left" Margin="242,159,0,0" VerticalAlignment="Top" Width="75"/>

    </Grid>
</Window>

我已经读过这篇文章，但它对我不起作用..并且无法理解我该如何正确编码..请帮我解决这个问题..希望尽快得到任何回复..thx

ObservesProperty method isn't observing model's properties at Prism 6

Answer 1

1) 你不能随心所欲地使用复杂的数据模型，所以试试吧

private myPErson _MyPerson;
    public myPErson MyPerson
    {
        get { return _MyPerson; }
        set
        {
            if (_MyPerson != null)
                _MyPerson.PropertyChanged -= MyPersonOnPropertyChanged;

            SetProperty(ref _MyPerson, value);


            if (_MyPerson != null)
                _MyPerson.PropertyChanged += MyPersonOnPropertyChanged;
        }
    }

    private void MyPersonOnPropertyChanged(object sender, PropertyChangedEventArgs propertyChangedEventArgs)
    {
        updateCommand.RaiseCanExecuteChanged();
    }

2) 改变你的构造函数

public Person()
    {
        MyPerson = new myPErson();
        updateCommand = new DelegateCommand(Execute, CanExecute);
    }