如何在不使用XAML的情况下在DataGrid中使用计算列？

using System;
using System.Windows.Controls;

public class CalculatedColumn : DataGridBoundColumn
{
    public static readonly DependencyProperty ExpressionProperty =
        DependencyProperty.Register("Expression", typeof(string), typeof(CalculatedColumn));

    public string Expression
    {
        get { return (string)GetValue(ExpressionProperty); }
        set { SetValue(ExpressionProperty, value); }
    }

    protected override FrameworkElement GenerateElement(DataGridCell cell, object dataItem)
    {
        var textBlock = new TextBlock();
        textBlock.SetBinding(TextBlock.TextProperty, Binding);
        return textBlock;
    }

    protected override FrameworkElement GenerateEditingElement(DataGridCell cell, object dataItem)
    {
        var textBox = new TextBox();
        textBox.SetBinding(TextBox.TextProperty, Binding);
        return textBox;
    }

    protected override object PrepareCellForEdit(FrameworkElement editingElement, RoutedEventArgs editingEventArgs)
    {
        var textBox = editingElement as TextBox;
        if (textBox != null)
        {
            // 计算并更新计算列的值
            textBox.Text = CalculateExpression(Expression);
        }
        return textBox.Text;
    }

    private string CalculateExpression(string expression)
    {
        // 在这里实现计算列的计算逻辑
        // 可以使用DataTable.Compute方法或其他适当的方法来计算表达式
        // 返回计算结果的字符串表示
        return "Calculated Value";
    }
}

var dataGrid = new DataGrid();
var calculatedColumn = new CalculatedColumn();
calculatedColumn.Binding = new Binding("PropertyName"); // 绑定到数据源的属性
calculatedColumn.Expression = "Expression"; // 设置计算列的表达式
dataGrid.Columns.Add(calculatedColumn);