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我正在做一個溫度轉換器作爲測試項目。它有三個應該相互溝通的上/下控制。 （右邊的標籤僅用於調試。）當我通過旋轉（例如攝氏度）更改溫度時，其相應標籤會正確更新，但我也希望Kelvin和華氏溫度值同時更改。但他們沒有。爲什麼不？如何使輸入控件在MVVM（WPF）中相互通信？
其意圖是模型（TempModel）只應保留一個值（開爾文）。其他應在需要時計算。我嘗試了不同的方法來獲取攝氏和華氏值。在這種情況下，我有模型中的屬性從私有_Kelvin變量計算其值。它在啓動時工作，但不是在運行時更改值時。
我也試着用視圖模型中的屬性做類似的事情。
我相信解決方案非常簡單，並且與綁定有關，但我仍然無法找到它。
這裏是什麼樣子： User interface image
下面是這個視圖XAML代碼：
<Window x:Class="Temperature.MainWindow"
xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
xmlns:extToolkit="http://schemas.microsoft.com/winfx/2006/xaml/presentation/toolkit/extended"
Title="Temperature converter" Height="183" Width="468">
<Grid VerticalAlignment="Stretch">
<Label Content="Kelvin" Height="28" HorizontalAlignment="Left" Margin="10,10,0,0" Name="label1" VerticalAlignment="Top" />
<extToolkit:DoubleUpDown Name="_KelvinUD" Increment="0.1" FormatString="F2" Value="{Binding Kelvin}" HorizontalAlignment="Left" Width="100" VerticalAlignment="Top" Margin="113,14,0,0" />
<Label Height="28" HorizontalAlignment="Left" Margin="279,10,0,0" Name="label4" VerticalAlignment="Top" Content="{Binding Kelvin}" />
<Label Content="Celsius" Height="28" HorizontalAlignment="Left" Margin="12,44,0,0" Name="label2" VerticalAlignment="Top" />
<extToolkit:DoubleUpDown Name="_CelsiusUD" Increment="0.1" FormatString="F2" Value="{Binding Celsius}" HorizontalAlignment="Left" Width="100" VerticalAlignment="Top" Margin="113,48,0,0" />
<Label Height="28" HorizontalAlignment="Left" Margin="279,44,0,0" Name="label5" VerticalAlignment="Top" Content="{Binding Celsius}" />
<Label Content="Fahrenheit" Height="28" HorizontalAlignment="Left" Margin="12,78,0,0" Name="label3" VerticalAlignment="Top" />
<extToolkit:DoubleUpDown Name="_FarenheitUD" Increment="0.1" FormatString="F2" Value="{Binding Fahrenheit}" HorizontalAlignment="Left" Width="100" VerticalAlignment="Top" Margin="113,82,0,0" />
<Label Height="28" HorizontalAlignment="Left" Margin="279,78,0,0" Name="label6" VerticalAlignment="Top" Content="{Binding Fahrenheit}" />
</Grid>
背後的代碼：
using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Windows;
using System.Windows.Controls;
using System.Windows.Data;
using System.Windows.Documents;
using System.Windows.Input;
using System.Windows.Media;
using System.Windows.Media.Imaging;
using System.Windows.Navigation;
using System.Windows.Shapes;
namespace Temperature
{
public partial class MainWindow : Window
{
private TempViewModel _viewModel = new TempViewModel();
TempViewModel ViewModel
{
get { return _viewModel; }
}
public MainWindow()
{
InitializeComponent();
base.DataContext = ViewModel;
}
}
}
型號：
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.ComponentModel;
namespace Temperature
{
public class TempModel
{
private double _kelvin;
public double Kelvin
{
get
{
return _kelvin;
}
set
{
_kelvin = value;
OnPropertyChanged("Kelvin");
}
}
public double Celsius
{
get
{
return _kelvin - 273.15;
}
set
{
_kelvin = value + 273.15;
OnPropertyChanged("Celsius");
}
}
public double Fahrenheit
{
get
{
return 9.0/5.0 * (_kelvin - 273.15) + 32;
}
set
{
_kelvin = 5.0/9.0 * (value - 32) + 273.15;
OnPropertyChanged("Fahrenheit");
}
}
public event PropertyChangedEventHandler PropertyChanged;
private void OnPropertyChanged(string propertyName)
{
if (PropertyChanged != null)
{
PropertyChanged(this, new PropertyChangedEventArgs(propertyName));
}
}
}
}
視圖模型：
using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
namespace Temperature
{
class TempViewModel
{
TempModel _tempModel;
public TempViewModel()
{
_tempModel = new TempModel
{
Kelvin = 300.15 // Initial value
};
}
public TempModel TempModel
{
get
{
return _tempModel;
}
set
{
_tempModel = value;
}
}
public double Kelvin
{
get
{
return _tempModel.Kelvin;
}
set
{
_tempModel.Kelvin = value;
}
}
public double Celsius
{
get
{
return _tempModel.Celsius;
}
set
{
_tempModel.Celsius = value;
}
}
public double Fahrenheit
{
get
{
return _tempModel.Fahrenheit;
}
set
{
_tempModel.Fahrenheit = value;
}
}
}
}
'公共類TempModel：INotifyPropertyChanged'和下面的@blindmeis答案的組合使它工作。謝謝！ – junior