在WPF中对DataGrid进行TwoWay绑定 [英] TwoWay binding on a DataGrid in WPF

问题描述

我有一个WPF数据网格，我正在使用

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;

我想使用两种方式绑定来更改任何值或当添加新行。

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

<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列为空之外，所有代码都为空。

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

我对如何做到最好的方法一无所知，因此将不胜感激。

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

推荐答案

您的 DataGridTextColumn 的所有 Bindings 除了 PerP列外，均指定了两次路径。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}"/>

在这里，您的 Binding 首先指定路径设为 ProductCode，然后还将其指定为 IsSelected。由于要绑定到网格的集合中的对象没有 IsSelected属性，因此，如果在调试器下运行此属性，则应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.

您的数据源为一个匿名类型的集合，因此 var 是必需的，但是正如其他人所说的那样，对该集合进行双向绑定将无法用于更新回源。

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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