c# 从 LINQ 对象填充树视图 [英] c# populate treeview from LINQ object

问题描述

我有一个 linq 对象，我正在尝试使用 c# winforms 填充树视图.

I have a linq object that i'm trying to fill a treeview from using c# winforms.

样品

Column 1   Column 2   Column 3        
Test 1     Item A     Sub Item 1      
Test 1     Item A     Sub Item 2      
Test 1     Item A     Sub Item 3      
Test 1     Item B     Sub Item 1      
Test 1     Item B     Sub Item 2     
Test 1     Item B     Sub Item 3  

并像填充树视图一样

Test 1 (CheckBox)
------Item A (CheckBox)
-------------Sub Item 1  (CheckBox)
-------------Sub Item 2  (CheckBox)
-------------Sub Item 3  (CheckBox)
------Item B (CheckBox)
-------------Sub Item 1  (CheckBox)
-------------Sub Item 2  (CheckBox)
-------------Sub Item 3  (CheckBox)

实现这一目标的最简单方法是什么?

What is the easiest way to achieve this?

谢谢喷

推荐答案

好吧，如果您执行以下查询:

Well, if you perform the following query:

var query = data.GroupBy(item => item.Column1)
                .Select(group => group.GroupBy(item => item.Column2))
                .Select(group => group.Select(innerGroup => 
                    innerGroup.GroupBy(item => item.Column3)));

您将首先按第 1 列分组所有项目，然后按第 2 和第 3 列分组，因此它已在树结构中.现在你只需要有 3 个嵌套的 for 循环来将项目添加到树视图中.

You will have all of the items grouped first by column1, then 2 and 3, so It's already in a tree structure. Now you just need to have 3 nested for loops to add the items to the treeview.

foreach (var outermostGroup in query)
{
    //add node for outermostGroup's key
    foreach (var middleGroup in outermostGroup)
    {
        //add child node of the above node for middleGroup key
        foreach (var innerGroup in middleGroup)
        {
            //add child node of the above node for innerGroup key
        }
    }
}

显然，此代码仅适用于具有固定(最大)深度的固定数量的列.如果您不知道列数并且可以具有任意深度，那么您需要一种完全不同的方法.

Clearly this code only works if there are a fixed number of columns with a fixed (max) depth. If you don't know the number of columns and can have an arbitrary depth then you'd need a fairly radically different approach.

这篇关于c# 从 LINQ 对象填充树视图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IT屋！