如何使用 x/y 坐标而不是索引访问 Grid 中的子项?

How to access children in Grid with x/y coordinates instead of index?(如何使用 x/y 坐标而不是索引访问 Grid 中的子项?)

问题描述

我有一个 Grid 对象，想从中取出一个特定的复选框.

I have a Grid object and want to get a specific checkbox out of it.

我可以使用这个语法:

CheckBox cbChange = grid.Children[4] as CheckBox;

但是我怎样才能通过 x/y 坐标访问这个孩子，例如:

CheckBox cbChange = grid.GetXYChild(2,3) as CheckBox; //PSEUDO-CODE

using System.Collections.Generic;
using System.Windows;
using System.Windows.Controls;
using System.Windows.Documents;

namespace TestGrid92292
{
    public partial class Window1 : Window
    {
        public Window1()
        {
            InitializeComponent();

            List<string> rowNames = new List<string>
            {
                "Marketing",
                "Sales",
                "Development"
            };

            Grid grid = new Grid();
            grid.Margin = new Thickness(5);

            ColumnDefinition col1 = new ColumnDefinition();
            col1.Width = new GridLength(100, GridUnitType.Pixel);
            grid.ColumnDefinitions.Add(col1);

            ColumnDefinition col2 = new ColumnDefinition();
            col2.Width = new GridLength(1, GridUnitType.Star);
            grid.ColumnDefinitions.Add(col2);

            ColumnDefinition col3 = new ColumnDefinition();
            col3.Width = new GridLength(1, GridUnitType.Star);
            grid.ColumnDefinitions.Add(col3);

            int rowCount = 0;
            foreach (var rowName in rowNames)
            {
                RowDefinition row = new RowDefinition();
                grid.RowDefinitions.Add(row);

                TextBlock tb = new TextBlock();
                tb.Text = rowName;
                tb.SetValue(Grid.ColumnProperty, 0);
                tb.SetValue(Grid.RowProperty, rowCount);
                grid.Children.Add(tb);

                CheckBox cb = new CheckBox();
                cb.SetValue(Grid.ColumnProperty, 1);
                cb.SetValue(Grid.RowProperty, rowCount);
                cb.HorizontalAlignment = HorizontalAlignment.Left;
                grid.Children.Add(cb);

                CheckBox cb2 = new CheckBox();
                cb2.SetValue(Grid.ColumnProperty, 2);
                cb2.SetValue(Grid.RowProperty, rowCount);
                cb2.HorizontalAlignment = HorizontalAlignment.Left;
                grid.Children.Add(cb2);

                rowCount++;
            }

            //check a specific box
            //CheckBox cbChange = grid.GetXYChild(2,3) as CheckBox;
            CheckBox cbChange = grid.Children[4] as CheckBox;
            cbChange.IsChecked = true;

            MainContent.Children.Add(grid);
        }
    }
}

推荐答案

我会创建一个扩展方法来获取所需的 x 和 y 值.在那里，您遍历所有子项并检查 Grid.GetRow(child) 和 Grid.GetColumn(child) 方法是否返回所需的值.

I would make an extension method that takes the desired x-and y-values. There in you go through all children and check if the Grid.GetRow(child) and Grid.GetColumn(child)-methods return the desired values.

因此我会返回一个 IEnumerable<FrameworkElement> 因为你可以在这个位置有多个、一个或没有元素(不是在你的例子中，而是一般的这种方法).

As a result I would return an IEnumerable<FrameworkElement> because you can have more than one, one or no elements at this position (not in your example, but for such a method in general).

类似:

public static class GridExtensions {
    public static IEnumerable<FrameworkElement> GetXYChild(this Grid instance, int x, int y) {
        if (null == instance) {
            throw new ArgumentNullException("instance");
        }
        List<FrameworkElement> list = new List<FrameworkElement>();            
        foreach (FrameworkElement fe in instance.Children) {
            if (Grid.GetRow(fe) == y && Grid.GetColumn(fe) == x) {
                list.Add(fe);
            }
        }
        return list;
    }
}

我没有测试过，如果不起作用，请发表评论.如果您只想返回一个实例，您可以相应地更改代码.

I have not tested it, make a comment if it does not work. If you only want to return one instance, you can change the code acordingly.

这篇关于如何使用 x/y 坐标而不是索引访问 Grid 中的子项?的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持编程学习网！