c# - 在DataGrid中选择多个单元格并输出到Excel工作表

Question

我有一个包含数百行和两列数据的 DataGrid。我需要以编程方式选择 DataGrid 中的特定行和特定单元格，并将它们输出到 Excel 工作表上。在做了一些研究之后，似乎获得单元格值的唯一方法是编写一个辅助函数，并且每次获得一个单元格值时辅助函数都会运行。

是否有更简单/更快捷的方法来获取 DataGrid 中特定单元格的值？或者，当每个单元格值转到 DataGrid 并将数组输出到 Excel 而不是 DataGrid 时，我是否应该同时将每个单元格值存储到一个数组中？

Answer 1

假设 DataGrid 显示员工信息，我们为每个员工存储他的 Id、Name 和 Address。让我们为每个员工属性添加一个额外的 bool 属性(例如 Id 和 IsIdSelected、Name 和 IsNameSelected)这个 bool 值属性将绑定(bind)到 DataGrid.IsSelected 属性，因此，它表示单元格是否被选中，您也可以通过将其设置为 来使用它以编程方式选择显示指定属性的单元格>正确。见以下代码:

/// <summary>
/// A class that represents an employee. Notice that with each property
/// (e.g. Id) there is a Boolean property that has a similar name (e.g. IsIdSelected)
/// this Boolean property will be bound to the relevant DataGridCell.IsSelected
/// property to indicate whether the cell representing this property were selected
/// or not. In other words if you want to know the selected properties at any moment
/// you just need to iterate through the employees collection, and examine each
/// Boolean property for each property :D
/// </summary>
public class Employee
{
    public int? Id { get; set; }
    public bool IsIdSelected { get; set; }

    public string Name { get; set; }
    public bool IsNameSelected { get; set; }

    public string Address { get; set; }
    public bool IsAddressSelected { get; set; }
}

背后的代码:

using System.Collections.ObjectModel;
using System.Windows;

namespace CellSelection
{
    public partial class MainWindow : Window
    {
        /// <summary>
        /// The DataGrid will be bound to this collection
        /// </summary>
        private ObservableCollection<Employee> _collection;

        public MainWindow()
        {
            InitializeComponent();

            // Initialize the employees collection with some test data
            _collection =
                new ObservableCollection<Employee>
                    {
                        new Employee {Id = 1, Name = "Mohammed A. Fadil", Address = "..."},
                        new Employee {Id = 485, Name = "Khalid Zein", Address = "..."},
                        new Employee {Id = 64, Name = "Ahmed Mubarak", Address = "..."},
                        new Employee {Id = 364, Name = "Ali Ebraheim", Address = "..."},
                    };

            DataContext = _collection;
        }

        private void OnExportButtonClick(object sender, RoutedEventArgs e)
        {
            // Now, concatinate all the selected cells
            var str = string.Empty;
            foreach (var emp in _collection)
            {
                if (emp.IsIdSelected)
                    str += string.Format("{0}, ", emp.Id);

                if (emp.IsNameSelected)
                    str += string.Format("{0}, ", emp.Name);

                if (emp.IsAddressSelected)
                    str += string.Format("{0}", emp.Address);

                str += "\n";
            }
            // Instead of displaying this message you could export these cells to Excel
            // in the format you need.
            MessageBox.Show(str);
        }
    }
}

XAML 代码:

<Window x:Class="CellSelection.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">
    <Grid>
        <Grid.RowDefinitions>
            <RowDefinition Height="275*" />
            <RowDefinition Height="36*" />
        </Grid.RowDefinitions>
        <DataGrid ItemsSource="{Binding}" AutoGenerateColumns="False"
                  SelectionMode="Extended" SelectionUnit="CellOrRowHeader">
            <DataGrid.Columns>

                <DataGridTextColumn Header="Id" Binding="{Binding Id}">
                    <DataGridTextColumn.CellStyle>
                        <Style TargetType="DataGridCell">
                            <Setter Property="IsSelected">
                                <Setter.Value>
                                    <Binding Path="IsIdSelected" Mode="TwoWay"
                                             UpdateSourceTrigger="PropertyChanged"/>
                                </Setter.Value>
                            </Setter>
                        </Style>
                    </DataGridTextColumn.CellStyle>
                </DataGridTextColumn>

                <DataGridTextColumn Header="Name" Binding="{Binding Name}">
                    <DataGridTextColumn.CellStyle>
                        <Style TargetType="DataGridCell">
                            <Setter Property="IsSelected">
                                <Setter.Value>
                                    <Binding Path="IsNameSelected" Mode="TwoWay"
                                             UpdateSourceTrigger="PropertyChanged"/>
                                </Setter.Value>
                            </Setter>
                        </Style>
                    </DataGridTextColumn.CellStyle>
                </DataGridTextColumn>

                <DataGridTextColumn Header="Address" Binding="{Binding Address}">
                    <DataGridTextColumn.CellStyle>
                        <Style TargetType="DataGridCell">
                            <Setter Property="IsSelected">
                                <Setter.Value>
                                    <Binding Path="IsAddressSelected" Mode="TwoWay"
                                             UpdateSourceTrigger="PropertyChanged"/>
                                </Setter.Value>
                            </Setter>
                        </Style>
                    </DataGridTextColumn.CellStyle>
                </DataGridTextColumn>
            </DataGrid.Columns>
        </DataGrid>
        <Button Content="Export Selection" Grid.Row="1" HorizontalAlignment="Right"
                Click="OnExportButtonClick" Margin="5"/>
    </Grid>
</Window>

请注意，对于每个 DataGrid 列，您必须添加一个 CellStyle，将每个列指定的 bool 属性绑定(bind)到它的 DataGridCell.IsSelected 属性，将此绑定(bind)模式设置为 Mode="TwoWay" 以支持以编程方式选择单元格(在这种情况下，您必须在 Employee 类)。

使用此解决方案，您不再需要辅助函数，也不再需要访问 DataGrid 实际单元格，只需遍历您的集合、确定所选属性并根据需要处理它们。