Question

我有一个DataGrid来输入销售屏幕的商品/价格/数量，我需要一个subTotal列，Price * Quantity，我不知道当用户离开Price时如何计算subTotal列或数量列。这是我的xaml

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<DataGrid ItemsSource="{Binding Path=Datos,Mode=TwoWay,NotifyOnSourceUpdated=True}" 
          SelectedItem="{Binding Dato,Mode=TwoWay,NotifyOnSourceUpdated=True}" 
          AutoGenerateColumns="False">
    <DataGrid.Columns>
        <DataGridTextColumn Header="Description" Binding="{ Binding Path=Descripcion}"></DataGridTextColumn>
        <DataGridTextColumn Header="Price" Binding="{ Binding Path=Precio,UpdateSourceTrigger=PropertyChanged}" ></DataGridTextColumn>
        <DataGridTextColumn Header="Quantity" Binding="{ Binding Path=Cant,UpdateSourceTrigger=PropertyChanged}"></DataGridTextColumn>
        <DataGridTextColumn Header="Total" Binding="{ Binding Path=Total,UpdateSourceTrigger=PropertyChanged}"></DataGridTextColumn>
    </DataGrid.Columns>
</DataGrid>

我的ViewModel是这样的：

 public class VM : VMBase
    {
        public VM()
        {

            Datos.Add(new CDato() { Descripcion = "item 1", Precio = 2.5m, Cant = 3m, Total = 7.5m });
            Datos.Add(new CDato() { Descripcion = "item 2", Precio = 5m, Cant = 2m, Total = 10m });
        }

        private ObservableCollection<CDato> _datos;

        public ObservableCollection<CDato> Datos
        {
            get
            {
                if (_datos == null)
                    _datos = new ObservableCollection<CDato>();
                return _datos;
            }
            set
            {
                _datos = value;
                RaisePropertyChanged();
            }
        }
        public void Calcular()
        {
            if (Dato != null)
            {
                Dato.Total = Dato.Precio * Dato.Cant;
                RaisePropertyChanged("Dato");
                RaisePropertyChanged("Datos");
            }
        }
        private CDato dato;

        public CDato Dato
        {
            get { return dato; }
            set
            {
                dato = value;
                RaisePropertyChanged();
            }
        }
    }

    public class CDato
    {
        public string Descripcion { get; set; }
        public decimal Precio { get; set; }
        public decimal Cant { get; set; }
        public decimal Total { get; set; }

    }

当用户更改单元格时，＃14; Precio＆＃34; （价格）或＆＃34; Cant＆＃34; （数量）＆＃34; Total＆＃34;必须使用此公式计算列Tota = Precio * Cant

我无法找到相关的样本。

你能帮我解决这个问题吗？

很多人

Answer 1

您可以通过向道具添加RaisePropertyChanged( "Total" )来创建此内容，用于计算Total属性。我已经创建了一些例子来解释如何。

<DataGrid ItemsSource="{Binding Objects}" AutoGenerateColumns="False">
    <DataGrid.Columns>
        <DataGridTextColumn Width="100" Binding="{Binding Price, UpdateSourceTrigger=PropertyChanged}" />
        <DataGridTextColumn Width="100" Binding="{Binding Total}" />
    </DataGrid.Columns>
</DataGrid>

viewModel道具。

private int _price;
public int Price
{
    get { return _price; }
    set { _price = value; RaisePropertyChanged( "Price" ); RaisePropertyChanged( "Total" ); }
}

public int Total
{
    get { return _price * 2; }
}

<强>更新根据评论。有必要为NotifyPropertyChanged类实施CDato（或从VMBase派生）并为其添加RaisePropertyChanged道具。

WPF DataGrid计算了Total列

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1 个答案: