treeview

左右值编码树形结构数据存储方案

由 耗尽温柔 提交于 2020-07-28 11:49:24
一、左右值编码 在基于数据库的一般应用中，查询的需求总要大于删除和修改。为了避免对于树形结构查询时的“递归”过程，基于Tree的前序遍历设计一种全新的无递归查询、无限分组的左右值编码方案，来保存该树的数据。 第一次看见这种表结构，相信大部分人都不清楚左值（Lft）和右值（Rgt）是如何计算出来的，而且这种表设计似乎并没有保存父子节点的继承关系。但当你用手指指着表中的数字从1数到18，你应该会发现点什么吧。对，你手指移动的顺序就是对这棵树进行前序遍历的顺序，如下图所示。当我们从根节点Food左侧开始，标记为1，并沿前序遍历的方向，依次在遍历的路径上标注数字，最后我们回到了根节点Food，并在右边写上了18。 依据此设计，我们可以推断出所有左值大于2，并且右值小于11的节点都是Fruit的后续节点，整棵树的结构通过左值和右值存储了下来。然而，这还不够，我们的目的是能够对树进行CRUD操作，即需要构造出与之配套的相关算法。按照深度优先，由左到右的原则遍历整个树，从1开始给每个节点标注上left值和right值，并将这两个值存入对应的name之中。 二、如何查询？ 1. 查询所有子节点 获取某个节点下的所有子孙节点，以Red为例： SELECT * FROM Tree WHERE Lft > 3 AND Lft < 6 ORDER BY Lft ASC 2. 子孙节点总数 子孙总数 =

Filter TreeView with all nodes and childs

由 拟墨画扇 提交于 2020-07-22 05:21:52
问题 I have a parent node which has a child, and this child has another child etc.. and they are all in a TreeView So I create a global variable to save all my nodes as: private TreeNodeCollection ProjectTreeView { get; set; } Then I set data of the tree node into my global variable: ProjectTreeView = this.tvProjectList.Nodes[0].Nodes; And When I click a button I want to filter my TreeView, so first I clear the TreeView, then I iterate over the collection and only show the nodes that meet my

Filter TreeView with all nodes and childs

由 早过忘川 提交于 2020-07-22 05:21:08
问题 I have a parent node which has a child, and this child has another child etc.. and they are all in a TreeView So I create a global variable to save all my nodes as: private TreeNodeCollection ProjectTreeView { get; set; } Then I set data of the tree node into my global variable: ProjectTreeView = this.tvProjectList.Nodes[0].Nodes; And When I click a button I want to filter my TreeView, so first I clear the TreeView, then I iterate over the collection and only show the nodes that meet my

Filter TreeView with all nodes and childs

由 偶尔善良 提交于 2020-07-22 05:20:01
问题 I have a parent node which has a child, and this child has another child etc.. and they are all in a TreeView So I create a global variable to save all my nodes as: private TreeNodeCollection ProjectTreeView { get; set; } Then I set data of the tree node into my global variable: ProjectTreeView = this.tvProjectList.Nodes[0].Nodes; And When I click a button I want to filter my TreeView, so first I clear the TreeView, then I iterate over the collection and only show the nodes that meet my

How to pass node id for each node clicked in kartik treeview?

由 社会主义新天地 提交于 2020-07-03 13:08:54
问题 I have multiple nodes. I want to show different views on each node click. For this, I have to pass the node id. Below is my code in which I have tried to explain the total scenario `<?= TreeView::widget([ 'query' => \common\models\MdcNode::find()->addOrderBy('root, lft'), 'headingOptions' => ['label' => 'Root'], 'rootOptions' => ['label'=>'<span class="text-primary">Root</span>'], 'topRootAsHeading' => true, // this will override the headingOptions //'displayValue' => 1, // initial display

How to pass node id for each node clicked in kartik treeview?

由 折月煮酒 提交于 2020-07-03 13:05:16
问题 I have multiple nodes. I want to show different views on each node click. For this, I have to pass the node id. Below is my code in which I have tried to explain the total scenario `<?= TreeView::widget([ 'query' => \common\models\MdcNode::find()->addOrderBy('root, lft'), 'headingOptions' => ['label' => 'Root'], 'rootOptions' => ['label'=>'<span class="text-primary">Root</span>'], 'topRootAsHeading' => true, // this will override the headingOptions //'displayValue' => 1, // initial display

Yii2 Show/Hide kartik treeview nodes

由 女生的网名这么多〃 提交于 2020-07-01 06:09:27
问题 I am using Kartik Tree Manager. I am able to add, remove, update nodes. There is more requirement, that is to show/hide nodes on the basis of user access. i.e. when a user is given a specific node(s) then only that particular node(s) with all the child (if any) should be shown. What I have done so far? I have created a table user-node in which I am assigning a node id to a user as shown below What I want to do Now I want to show only the specified node with its child node only and hide other

Populate file revision to treeview

由 ≯℡__Kan透↙ 提交于 2020-06-28 08:52:10
问题 I try to populate list of file revision to treeview. I have a list of revision file like a below. 1.17 1.17.1.1 1.17.1.2 1.17.1.2.1.1 1.17.1.2.1.2 1.17.1.2.1.2.1.1 1.17.1.2.1.2.1.2 1.17.1.2.1.2.1.3 1.17.1.2.1.2.1.3.1.1 1.17.1.2.1.2.1.3.1.2 1.17.1.2.1.2.1.3.2.1 1.17.1.2.1.2.1.4 1.17.1.2.1.2.1.5 1.17.1.2.1.2.1.5.1.1 1.17.1.2.1.2.1.5.1.2 1.17.1.2.1.2.1.5.1.2.1.1 1.17.1.2.1.3 1.17.1.2.1.4 1.18 1.19 Now, I would like to populate it like a 1.17 1.17.1.1 1.17.1.2 1.17.1.2.1.1 1.17.1.2.1.2 1.17.1.2.1

tkinter treeview click event for selected item [duplicate]

由 こ雲淡風輕ζ 提交于 2020-06-28 04:17:25
问题 This question already has answers here : Command for clicking on the items of a Tkinter Treeview widget? (3 answers) Closed 10 months ago . In my small tkinter app I have tree with such scructure as in the picture below. I want to make click event only when user will double click to last item of the tree (Amount1 or Amount2 etc.) Unfortunatly click event works when I click any item of the tree. How fix this behavior?! CODE: self.treeView.insert('', 'end', "parent", text=text) first_child =

Aftercheck and AfterSelect events in Treeview in Windows Forms

由 孤人 提交于 2020-06-26 07:13:26
问题 Im setting up a new Form and Im having some issuis with the TreeViewNodes checking and uncheking the childs. Its easier to see the problem in this short clip Normally it works properly but sometimes it gets stuck (I think there is a conflict with selection but Im not sure) and the methods arent applied properly. I have this methods to check and uncheck the childs: private void Treeview_AfterCheck(object sender, TreeViewEventArgs e) { if (e.Action != TreeViewAction.Unknown) if (e.Node.Checked)
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