带有点的 DataTable 列名是什么使它们不适合 WPF 的 DataGrid 控件? [英] What is it about DataTable Column Names with dots that makes them unsuitable for WPF's DataGrid control?

问题描述

运行这个，然后被搞糊涂了:

Run this, and be confused:

<Window x:Class="Data_Grids.MainWindow"
        xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
        xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
        Title="MainWindow" Height="350" Width="525">
    <StackPanel>
        <DataGrid
        Name="r1"
              ItemsSource="{Binding Path=.}">
        </DataGrid>
        <DataGrid
        Name="r2"
              ItemsSource="{Binding Path=.}">
        </DataGrid>
    </StackPanel>
</Window>

代码隐藏:

using System.Data;
using System.Windows;

namespace Data_Grids
{
    public partial class MainWindow : Window
    {
        public MainWindow()
        {
            InitializeComponent();

            DataTable dt1, dt2;
            dt1 = new DataTable();
            dt2 = new DataTable();
            dt1.Columns.Add("a-name", typeof(string));
            dt1.Columns.Add("b-name", typeof(string));
            dt1.Rows.Add(new object[] { 1, "Hi" });
            dt1.Rows.Add(new object[] { 2, "Hi" });
            dt1.Rows.Add(new object[] { 3, "Hi" });
            dt1.Rows.Add(new object[] { 4, "Hi" });
            dt1.Rows.Add(new object[] { 5, "Hi" });
            dt1.Rows.Add(new object[] { 6, "Hi" });
            dt1.Rows.Add(new object[] { 7, "Hi" });
            dt2.Columns.Add("a.name", typeof(string));
            dt2.Columns.Add("b.name", typeof(string));
            dt2.Rows.Add(new object[] { 1, "Hi" });
            dt2.Rows.Add(new object[] { 2, "Hi" });
            dt2.Rows.Add(new object[] { 3, "Hi" });
            dt2.Rows.Add(new object[] { 4, "Hi" });
            dt2.Rows.Add(new object[] { 5, "Hi" });
            dt2.Rows.Add(new object[] { 6, "Hi" });
            dt2.Rows.Add(new object[] { 7, "Hi" });
            r1.DataContext = dt1;
            r2.DataContext = dt2;
        }
    }
}

我会告诉你发生了什么.顶部数据网格填充有列标题和数据.底部数据网格有列标题，但所有行都是空白.

I'll tell you what happens. The top datagrid is populated with column headers and data. The bottom datagrid has column headers but all the rows are blank.

推荐答案

绑定路径解析器错误地解释了第二个表的列名中的句号.查看此示例运行时的调试输出，您可以看到自动生成的列已绑定到 'a' 和 'b' 而不是 'a.name' 和 'b.name'

The full stop character in the column names of the second table are incorrectly interpreted by the binding path parser. Look at the debug output while this example is running and you can see that the auto-generated columns have been bound to 'a' and 'b' rather than 'a.name' and 'b.name'

System.Windows.Data Error: 40 : BindingExpression path error: 'a' property not found on 'object' ''DataRowView' ... etc.
System.Windows.Data Error: 40 : BindingExpression path error: 'b' property not found on 'object' ''DataRowView' ... etc.

有许多不同的字符在绑定路径中具有特殊含义，包括句号 ('.')、斜线 ('/')、方括号 ('[',']') 和圆括号 ('(',')')，括号将导致您的应用程序崩溃.这些特殊字符可以通过用方括号包围绑定路径来转义.有关路径和字符转义的更多信息，请参见 绑定声明概述

There are a number of different characters which have special meaning in a binding path including full stop ('.'), slash ('/'), square brackets ('[',']') and parenthesis ('(',')'), the parenthesis will cause your app to crash. These special characters can be escaped by surrounding the binding path with square brackets. More information about paths and character escaping can be found in the Binding Declarations Overview

要解决此问题，您必须设置 AutoGenerateColumns="False" 并在 xaml 中指定列绑定:

To fix this you will have to set AutoGenerateColumns="False" and specify the column bindings in the xaml:

    <DataGrid
    x:Name="r2"
          ItemsSource="{Binding .}" AutoGenerateColumns="False">
        <DataGrid.Columns>
            <DataGridTextColumn Header="a.name" Binding="{Binding Path=[a.name]}" />
            <DataGridTextColumn Header="b.name" Binding="{Binding Path=[b.name]}" />
        </DataGrid.Columns>
    </DataGrid>

或以编程方式在后面的代码中

or programmatically in the code behind

        r2.AutoGenerateColumns = false;
        foreach( DataColumn column in dt2.Columns )
        {
            var gridColumn = new DataGridTextColumn()
            {
                Header = column.ColumnName,
                Binding = new Binding( "[" + column.ColumnName + "]" )
            };

            r2.Columns.Add( gridColumn );
        }

        r2.DataContext = dt2;

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