如何在列表框中对项目求和？

I have two ListBoxes, Source and Destination. The destination ListBox has Items selected by the user.

我有两个ListBox,Source和Destination。目标ListBox具有用户选择的项目。

How do I sum items in a destination ListBox?

如何汇总目的地ListBox中的项目?

The Destination ListBox has two data types String (Description) and decimal (Cost). I want to sum up only the Cost. Here is the XAML Code

Destination ListBox有两种数据类型String(Description)和decimal(Cost)。我只想总结成本。这是XAML代码

<ListBox Height="237" HorizontalAlignment="Left" Margin="44,191,0,0" Name="lstDestination" VerticalAlignment="Top" Width="264" Grid.ColumnSpan="2" ItemsSource="{Binding Source={StaticResource myItemList}}">
    <ListBox.ItemTemplate>
        <DataTemplate>
            <StackPanel Orientation="Vertical">
                <DockPanel >
                   <TextBlock FontWeight="Bold" Text="Item:"  DockPanel.Dock="Left" Margin="5,0,10,0"/>
                   <TextBlock Text="{Binding Path=Resource}" Foreground="Green" FontWeight="Bold" />
                   <TextBlock FontWeight="Bold" Text="Cost:"  DockPanel.Dock="Left" Margin="5,0,10,0"/>
                  <TextBlock Text="{Binding Path=Cost}" FontWeight="Bold" />
                </DockPanel>
            </StackPanel>
        </DataTemplate>
    </ListBox.ItemTemplate>
</ListBox>

This is the code I tried to sum up Cost:

这是我试图总结费用的代码:

private decimal SumDLstBox()
{
    decimal totalCost;
    foreach (var i in lstDestination.SelectedItems)
    {
        totalCost+=i.Cost; //Error is thrown here             
    }
    return totalCost;
}
//Data Source to List Box Source
 var items = from r in dc.IResources select r;
        lstSource.ItemsSource = items;

The user them selects the Items s/he needs, my challenge is to get the total of the selected items(Which have been moved to the ListBox Destination)

用户他们选择他/她需要的项目,我的挑战是获取所选项目的总数(已移动到ListBox目的地)

3 个解决方案

#1

To operate on your bound data, you should cast it to a list of the datatype you're working with. For eg.

要对绑定数据进行操作,您应该将其强制转换为您正在使用的数据类型列表。例如。

private decimal SumDLstBox()
{
    return lstDestination.SelectedItems.Cast<Foo>().Sum(f => f.Cost);
}

Where Foo is the datatype of the List you bound to the control.

其中Foo是绑定到控件的List的数据类型。

#2

Your .cs-file will know the property lstDestination. You can use a foreach loop to iterate through all elements in the lstDestination. In that same loop, you can add up the costing.

您的.cs文件将知道属性lstDestination。您可以使用foreach循环遍历lstDestination中的所有元素。在同一个循环中,您可以累计成本核算。

#3

Seems to me that you don't to iterate by lstDestination.SelectedItems but by the lstDestination.Items

在我看来,你不要通过lstDestination.SelectedItems迭代,而是通过lstDestination.Items迭代

#1