Question

我是WPF和C＃的新手，所以请帮助解决这个问题。我有一个DataGrid列，如下所示：“One”，“Two”，“Multiply”。

我输入数字“One”或“Two”的想法，并在“Multiply”列中得到结果。

当我编写代码并对其进行调试时，我可以看到正在重新计算属性的值。但是，除非我按空格键或点击我的上一栏，否则我不会显示在我的上一栏中。

以下是代码：

public class Numbers : INotifyPropertyChanged
{
    public event PropertyChangedEventHandler PropertyChanged; 

    private double _one;
    private double _two;
    private double _multiply;

    public double One
    {
        get { return _one; }
        set { _one = value; UpdateValue(); }
    }

    public double Two
    {
        get { return _two; }
        set { _two = value; UpdateValue(); }
    }

    public double Multiply
    {
        get { return _multiply; }
        set { _multiply = value; UpdateValue(); }
    }

    public Numbers(double pOne, double pTwo)
    {
        _one = pOne;
        _two = pTwo;
        _multiply = GetMultiply(); 
    }

    private void UpdateValue()
    {
        OnPropertyChanged("One");
        OnPropertyChanged("Two");
        OnPropertyChanged("Multiply");
        _multiply = GetMultiply();
    }

    private double GetMultiply()
    {
        return _one * _two;
    }

    protected void OnPropertyChanged(string name)
    {
        PropertyChangedEventHandler handler = PropertyChanged;

        if (handler != null)
        {
            handler(this, new PropertyChangedEventArgs(name));
        }
    }
}

public class Collection :  ObservableCollection<Numbers>  
{
    public ObservableCollection<Numbers> Numbers { get; set; }

    public Collection()
    {
        Numbers = new ObservableCollection<Numbers>();

        Numbers.Add(new Numbers(1, 2));
        Numbers.Add(new Numbers(2, 2)); 
    }
}

XAML：

<DataGrid x:Name="StockData" HorizontalAlignment="Left" Margin="0,0,0,0" VerticalAlignment="Top" ItemsSource="{Binding}" AutoGenerateColumns="False" LostFocus="StockData_LostFocus" >
    <DataGrid.Columns >
        <DataGridTextColumn Header="Number One" Width="100" Binding="{Binding One, Mode=TwoWay, UpdateSourceTrigger=PropertyChanged, StringFormat=\{0:C\}}" />
        <DataGridTextColumn Header="Number Two" Width="100" Binding="{Binding Two, Mode=TwoWay, UpdateSourceTrigger=PropertyChanged, StringFormat=\{0:C\}}" />
        <DataGridTextColumn Header="Total" Width="100" Binding="{Binding Multiply, BindsDirectlyToSource=True, Mode=TwoWay, StringFormat=\{0:C\}, UpdateSourceTrigger=PropertyChanged}" />
    </DataGrid.Columns>
</DataGrid>

Answer 1

您在提升PropertyChanged事件后设置为multip，因此UI不会收到值已更改的通知。

设置乘法然后提升PropertyChanged事件：

private void UpdateValue()
{
    _multiply = GetMultiply();
    OnPropertyChanged("One");
    OnPropertyChanged("Two");
    OnPropertyChanged("Multiply");
}

WPF DataGrid计算

1 个答案: