WPF 中 DataGrid 上的双向绑定 [英] TwoWay binding on a DataGrid in WPF

问题描述

我有一个 WPF DataGrid 正在使用

I have a WPF DataGrid that I am filling using

var allLines = from Lines in ctx.InvoiceLines join PerPs in ctx.ProductsViews on Lines.ProductCode equals PerPs.ProductCode 
               where (Lines.BranchNo == BrNo) && (Lines.Docket == Docket)
               select new { Lines.ProductCode, Lines.Description, Lines.Inv_Quantity, Lines.Grn_Quantity,
                Lines.Inv_Price,Lines.Grn_Price,Lines.Inv_Total, Lines.Grn_Total, Lines.AnalCode,
                Lines.Vat_Rate, Lines.GrnNo,Lines.Comment , PerPs.OuterUnits};

dgGrid.ItemsSource = allLines;

当任何值发生更改或添加新行时，我想使用两种方式绑定来更新数据库.这可能吗?

I want to use two way binding to update the database when any of the values are changed or when a new row is added. Is that possible?

我的 xaml 代码是

My xaml code is

<DataGrid Grid.Row="3" x:Name="dgGrid" DataContext="{Binding}" FontSize="16" HorizontalScrollBarVisibility="Visible" 
              VerticalScrollBarVisibility="Visible" SelectionUnit="FullRow" SelectionMode="Extended" AutoGenerateColumns="False"
              SelectionChanged="dgGrid_SelectionChanged" >
        <DataGrid.Columns>
            <DataGridTextColumn Width="Auto" Header="ProductCode"  Binding="{Binding ProductCode, Mode=TwoWay, Path=IsSelected, UpdateSourceTrigger=PropertyChanged}"/>
            <DataGridTextColumn Width="250" Header="Description"  Binding="{Binding Description,  Mode=TwoWay, Path=IsSelected, UpdateSourceTrigger=PropertyChanged}" FontSize="14"/>
            <DataGridTextColumn Width="61" Header="Inv_Quantity" Binding="{Binding Inv_Quantity,  Mode=TwoWay, Path=IsSelected, UpdateSourceTrigger=PropertyChanged}"/>
            <DataGridTextColumn Width="63" Header="Grn_Quantity" Binding="{Binding Grn_Quantity,  Mode=TwoWay, Path=IsSelected, UpdateSourceTrigger=PropertyChanged}"/>
            <DataGridTextColumn Width="59" Header="Inv_Price" Binding="{Binding Inv_Price,  Mode=TwoWay, Path=IsSelected, UpdateSourceTrigger=PropertyChanged}"/>
            <DataGridTextColumn Width="61" Header="Ord_Price" Binding="{Binding Grn_Price,  Mode=TwoWay, Path=IsSelected, UpdateSourceTrigger=PropertyChanged}"/>
            <DataGridTextColumn Width="72" Header="Inv_Total" Binding="{Binding Inv_Total, Converter={StaticResource Currency},  Mode=TwoWay, Path=IsSelected, UpdateSourceTrigger=PropertyChanged}"/>
            <DataGridTextColumn Width="74" Header="Grn_Total" Binding="{Binding Grn_Total, Converter={StaticResource Currency},  Mode=TwoWay, Path=IsSelected, UpdateSourceTrigger=PropertyChanged}"/>
            <DataGridTextColumn Width="58" Header="AnalCode" Binding="{Binding AnalCode,  Mode=TwoWay, Path=IsSelected, UpdateSourceTrigger=PropertyChanged}"/>
            <DataGridTextColumn Width="40" Header="Vat_Rate" Binding="{Binding Vat_Rate,  Mode=TwoWay, Path=IsSelected, UpdateSourceTrigger=PropertyChanged}"/>
            <DataGridTextColumn Width="Auto" Header="GrnNo"  Binding="{Binding GrnNo,  Mode=TwoWay, Path=IsSelected, UpdateSourceTrigger=PropertyChanged}"/>
            <DataGridTextColumn Width="Auto" Header="Comment" Binding="{Binding Comment, Mode=TwoWay, Path=IsSelected, UpdateSourceTrigger=PropertyChanged}"/>
            <DataGridTextColumn Width="Auto" Header="PerP" Binding="{Binding OuterUnits}" IsReadOnly="True"/>
        </DataGrid.Columns>
        <DataGrid.Resources>
            <SolidColorBrush x:Key="{x:Static SystemColors.HighlightBrushKey}" Color="LightSteelBlue"/>
        </DataGrid.Resources>
    </DataGrid>

当我运行此代码时，除了 PerP 列之外的所有内容都是空的.

When I run this code all but the PerP column is empty.

我非常不知道如何做到最好，因此非常感谢您的帮助.

I'm quite lost as to how to do the best way so any help will be very much appreciated.

推荐答案

除了PerP"列之外，您的 DataGridTextColumn 的所有 Bindings 都指定了两次路径.例如:

All the Bindings for your DataGridTextColumn besides the "PerP" column are specifying the path twice. For example:

<DataGridTextColumn Width="Auto" Header="ProductCode"  Binding="{Binding ProductCode, Mode=TwoWay, Path=IsSelected, UpdateSourceTrigger=PropertyChanged}"/>

此处您的 Binding 首先将路径指定为ProductCode"，然后还将其指定为IsSelected".由于您绑定到网格的集合中的对象没有IsSelected"属性，如果您在调试器下运行它，您应该会在输出"窗口中看到绑定错误.如果删除这些绑定的 Path=IsSelected，则列值应该正确绑定.

Here your Binding is first specifying the path to be "ProductCode" and then also specifying it to be "IsSelected". Since there is no "IsSelected" property on the objects in the collection that you are binding to the grid, if you run this under the debugger you should see binding errors in the Output window. If you remove the Path=IsSelected for those bindings then the column values should be bound correctly.

您的数据源是一个匿名类型的集合，因此 var 是必要的，但正如其他人所说的那样，对该集合的双向绑定不适用于更新回源.

Your datasource is a collection of an anonymous type so the var is necessary, but as others have said two-way binding to that collection isn't going to work for updates back to the source.

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