一个超级简单的MVVM-Light WP7样本？

Question

我正在寻找一个样本,以最轻微的方式演示以下内容:

一个调用基于SOAP的Web服务的模型; 定期轮询以获取最新值(假设SOAP服务返回一个布尔值).该模型还应支持调用更改服务器上的布尔值的SOAP方法.

一个ViewModel,它允许底层布尔值绑定到View中的控件(例如,复选框).

具有上述复选框控件的视图绑定到基础布尔值.根据轮询间隔,复选框将随服务器状态的变化而更新.如果单击该复选框,则会将事件分派给模型,从而导致服务器更新.

最好这个样本可以在Windows Phone 7上运行,但是在紧要关头我会对支持SL3的东西感到满意(不允许使用SL4命令路由).

我正在努力学习如何让MVVM-Light为我工作,我怀疑专家可以很快地对这样的代码进行编码...我也怀疑这是很多应用程序的相当常见的模式.

Answer 1

米克N为指针帮助,但真正让我渡过了难关是这个职位由Jeremy Likness: http://csharperimage.jeremylikness.com/2010/04/model-view-viewmodel-mvvm-explained.html

下面是其他人的利益的样品(假设我没有做什么傻事):

首先,我开始使用MVVM光强的Windows Phone 7项目.

我在MainPage.xaml中添加了一个复选框:

    <CheckBox Content="Switch 1" 
              IsChecked="{Binding Switch1.PowerState, Mode=TwoWay}"
              Height="72" HorizontalAlignment="Left" Margin="24,233,0,0" 
              Name="checkBox1" VerticalAlignment="Top" Width="428" />

public class OnOffSwitchClass : ViewModelBase // ignore that it's derived from ViewModelBase!
{
    private const Int32 TIMER_INTERVAL = 5000;  // 5 seconds
    private Timer _timer;

    // Upon creation create a timer that changes the value every 5 seconds
    public OnOffSwitchClass()
    {
        _timer = new System.Threading.Timer(TimerCB, this, TIMER_INTERVAL, TIMER_INTERVAL);
    }

    private static void TimerCB(object state)
    {
        // Alternate between on and off
        ((OnOffSwitchClass)state).PowerState = !((OnOffSwitchClass)state).PowerState;
    }

    public const string PowerStatePropertyName = "PowerState";

    private bool _myProperty = false;

    public bool PowerState
    {
        get
        {
            return _myProperty;
        }

        set
        {
            if (_myProperty == value)
            {
                return;
            }

            var oldValue = _myProperty;
            _myProperty = value;

            // Update bindings and broadcast change using GalaSoft.MvvmLight.Messenging
            GalaSoft.MvvmLight.Threading.DispatcherHelper.CheckBeginInvokeOnUI(() =>
                RaisePropertyChanged(PowerStatePropertyName, oldValue, value, true));
        }
    }
}

private OnOffSwitchClass _Switch1 = new OnOffSwitchClass();

public OnOffSwitchClass Switch1 
{
    get
    {
        return _Switch1;
    }
}

    <CheckBox Content="Switch 1" 
              IsChecked="{Binding Switch1.PowerState, Mode=TwoWay}"
              Height="72" HorizontalAlignment="Left" Margin="24,233,0,0" 
              Name="checkBox1" VerticalAlignment="Top" Width="428" />

public class OnOffSwitchClass : ViewModelBase // ignore that it's derived from ViewModelBase!
{
    private const Int32 TIMER_INTERVAL = 5000;  // 5 seconds
    private Timer _timer;

    // Upon creation create a timer that changes the value every 5 seconds
    public OnOffSwitchClass()
    {
        _timer = new System.Threading.Timer(TimerCB, this, TIMER_INTERVAL, TIMER_INTERVAL);
    }

    private static void TimerCB(object state)
    {
        // Alternate between on and off
        ((OnOffSwitchClass)state).PowerState = !((OnOffSwitchClass)state).PowerState;
    }

    public const string PowerStatePropertyName = "PowerState";

    private bool _myProperty = false;

    public bool PowerState
    {
        get
        {
            return _myProperty;
        }

        set
        {
            if (_myProperty == value)
            {
                return;
            }

            var oldValue = _myProperty;
            _myProperty = value;

            // Update bindings and broadcast change using GalaSoft.MvvmLight.Messenging
            GalaSoft.MvvmLight.Threading.DispatcherHelper.CheckBeginInvokeOnUI(() =>
                RaisePropertyChanged(PowerStatePropertyName, oldValue, value, true));
        }
    }
}

我添加了对DispatcherHelper.Initialize()的调用; 在我的App()构造函数中.

这看起来不错吗？