Question

我刚刚开始学习MVVM。告诉我View，Model和ViewModel应该包含什么。

程序显示一个计时器，它也是一个输入字段。如果您在其中输入0到72000之间的数值并更改字段的焦点，则输入的值将转换为hh / mm / ss格式，然后开始倒计时。

一切都放在正确的地方了吗？尚不清楚应在何处实现此功能：

TextBoxGotKeyboardFocus
TextBoxLostKeyboardFocus
ButtonChangeFocus-我只需要此按钮即可更改焦点，但是有趣的是应该在何处实现此功能

查看

此处已连接DataContext

<Window.DataContext>
    <viewmodel:MainViewModel/>
</Window.DataContext>

<Grid Margin="0,0,3.6,5.2">
    <TextBox Name="textTimeTop"
             GotKeyboardFocus="TextBoxGotKeyboardFocus" 
             LostKeyboardFocus="TextBoxLostKeyboardFocus"                 
             Text="{Binding Seconds, ValidatesOnDataErrors=True, UpdateSourceTrigger=PropertyChanged}"/>
    <Button Content="Change Focus" Click="ButtonChangeFocus"/>
</Grid>

模型

计时器

class TestTimer
{
    private DispatcherTimer Timer;

    public void StartTimer()
    {
        Timer = new DispatcherTimer();
        Timer.Interval = new TimeSpan(0, 0, 1);
        Timer.Tick += Timer_Tick;
        Timer.Start();
    }

    private void Timer_Tick(object sender, EventArgs e)
    {
    }
}

ViewModel

此处声明的字段和属性

// Removed code for hours and minutes
class MainViewModel : INotifyPropertyChanged
{
    private int _userInputSeconds;
    public int UserInputSeconds
    {
        get { return _userInputSeconds; }
        set
        {
            if (_userInputSeconds < 0 || _userInputSeconds > 72000)
                throw new ArgumentException("Wrong data, allows only 0..72000");
            _userInputSeconds = value;
        }
    }

    private int _seconds;
    public int Seconds
    {
        get { return _seconds; }
        set
        {
            _seconds = value;
            OnPropertyChanged("Seconds");
        }
    }

    public event PropertyChangedEventHandler PropertyChanged;
    public void OnPropertyChanged([CallerMemberName]string prop = "")
    {
        PropertyChanged?.Invoke(this, new PropertyChangedEventArgs(prop));
    }
}

Timer程序中的MVVM体系结构

0 个答案: