• Qtreewidget drag node


    1、 Foreword When using qtreewidget to create a tree bar, it is expected that nodes can be moved to different groups by dragging, but the group prohibits dragging; Nodes are only divided into groups (parent nodes) and children. When child a is dragged to Child B of another group x, a is regarded as a […]

  • Android listview


    Listview is one of the most commonly used controls in Android. Almost all applications use it, so it is very important to learn to use it. Now let’s understand the usage of listview from an example. Let’s take a look at the project structure diagram of our example Here we first look at fruit, fruit […]

  • Brief introduction to the [flutter doc] widget


    Introduction to widgets Flutter widget is created from the modern framework inspired by react. Its core idea is to use widgets to create your user interface. Widgets describe what configuration and state are given to them and what they should look like. When the state of a widget changes, the widget will be reconstructed according […]

  • Implementation of flex layout to keep children high


    After using flex layout, you will find that the height of all sub items will be the same after horizontal arrangement.   This is because flex layout defaults to: Make all the subitems horizontal. The default is not wrap. Make the subitem as wide as its content, and change the height of all subitems to […]

  • Tkinter tree view ttk.Treeview


    Description of TTK tree view components Components can contain multiple columns. The first column is called the icon column, which is used to display the collapsed or expanded icon. The other columns can be used to display other information project explain item In the tree structure, each item iid Each item has a separate identification […]

  • Easy page layout with flex layout


    I don’t want to say much nonsense, but I’ll go to the code directly 1. Top, middle and bottom layout: <!DOCTYPE html> <html lang=”en”> <head> <meta charset=”UTF-8″> <meta name=”viewport” content=”width=device-width, initial-scale=1.0″> <title>Document</title> <style> body { position: absolute; left: 0; right: 0; top: 0; bottom: 0; padding: 0; margin: 0; display: flex; flex-direction: column; } .header, .footer […]

  • Bug of uistackview: hide animation failure.


    There is a probability that the layout of uistackview’s children will be successful when doing hide animation, but they can’t hide the children successfully. Solution: avoid triggering hide again for hidden children if(v.isHidden == NO) {   [v setHidden:1]; }  

  • WPF: (4) sample collection of styles and templates


    Source project address: https://github.com/Microsoft/…The following is the conversion of the sample into a brief description, and gives the actual operation effect and key code: – Alternatingappearanceofitems sub item color alternating rendering Set collection view source record grouping property description item <local:Places x:Key=”Places”/> <!–Group the items by State.–> <CollectionViewSource Source=”{StaticResource Places}” x:Key=”GroupedData”> <CollectionViewSource.GroupDescriptions> <PropertyGroupDescription PropertyName=”State”/> </CollectionViewSource.GroupDescriptions> […]

  • Flex elastic box


    How to turn on Flex <style> /*Parent on*/ div { display: flex; } /*Subitem*/ div span { width: 150px; height: 100px; background-color: red; } </style> <body> <div> <span>1</span> <span>2</span> <span>3</span> </div> </body> Flex layout parent common properties attribute explain flex-direction Set spindle direction justify-content Set the arrangement of sub elements on the spindle flex-wrap Set […]

  • Basic usage of regular expression


    Basic grammar Single character Number: \ D is equivalent to [0-9] Number or letter (underscore): [w is equivalent to [a-za-z0-9] Non numeric and alphabetic (underscore): \ W is equivalent to [^ a-za-z0-9 ‘] Spaces and tab: \ s match any white space characters, including spaces, tabs, page breaks, and so on. Equivalent to [\ f […]