Lesson 5 Basic _ multi-table query

Lesson 5 Basic _ multi-table query 1. Multi-table relations In project development, when designing database table structure, the table structure will be analyzed and designed according to the business requirements and the relationship between business modules. Because business is related to each other, there are also various connections among ...

Added by joeiscoolone on Mon, 07 Mar 2022 19:47:01 +0200

Open camera after android 7.0 to take avatar upload

Today, I'm doing android development related to this avatar. I keep looking for data on the Internet and don't know anything. Then I copy it. What's the problem? Now android can open a camera without simply asking for it. According to the data I found today, the URI of the file can't be used outside of this APP, so a conversion is needed. Then ...

Added by ggkfc on Sun, 06 Mar 2022 20:22:30 +0200

CH9 network programming

target Understand the introduction of HTTP protocol communication, and be able to say what is HTTP protocolMaster the usage of HttpURLConnection and be able to use HttpURLConnection to access the networkMaster the use of WebView control, and be able to use WebView control to load different web pagesMaster the parsing of JSON data and be ab ...

Added by dhimok on Sun, 06 Mar 2022 16:59:06 +0200

[UI interface development] basic component - switch

abstract This chapter is to learn and summarize the knowledge of Toggle in UGUI.In order to better explain their views, this article attempts to analyze some common functions of Toggle from the perspective of "self-made imitation" Toggle Essentials For a Toggle, its biggest feature is that it has two states: on / off, correspon ...

Added by Cramblit on Thu, 03 Mar 2022 06:31:25 +0200

Mobile phone number validation latest regular expression

Generally, the form page needs to fill in the mobile phone number. To verify whether the mobile phone number entered by the user is correct, we need to use the regular expression to match the mobile phone number segment. If it is in the operator number segment, the number is correct. Therefore, it is necessary to know the latest segment number ...

Added by lJesterl on Tue, 01 Mar 2022 21:32:39 +0200

Event distribution mechanism of View

What did the VIew incident include The event of View actually refers to MotionEvent, that is, a series of actions such as clicking, sliding and lifting the screen. It has the following four event types ACTION_DOWN: the finger just touched the screenACTION_MOVE: move your finger on the screenACTION_UP: the moment when the finger is release ...

Added by jlh3590 on Sun, 27 Feb 2022 12:00:31 +0200

Draw drawing process of UI drawing process

preface From the previous articles, we can know the measurement and layout of ui. This time, let's first pay attention to how our ui is drawn. So here we first need to understand the specific drawing process and the role of paint and Canvas in this process Drawing process In previous courses, we mentioned that performmeasure, performlayout a ...

Added by pneudralics on Tue, 15 Feb 2022 16:10:55 +0200

7 - visual control base class QWidget

7 - QWidget QWidget VS QObject QObject is not a visual control, but the base class of all QT objects. Qwidget is the base class of all visual controls. (1) Description The base class of all visual controls (only common to all visual controls, such as a square, resizable, moving position, etc.); Is the simplest blank control; Control is ...

Added by Swerve1000 on Tue, 15 Feb 2022 05:31:36 +0200

element ui upload picture usage

Through slot You can import custom upload button types and text prompts. You can limit the number of uploaded files and define the behavior when the limit is exceeded by setting limit and on-exceed ed. You can prevent file removal by setting before remove. <el-upload class="upload-demo" action="https://jsonplaceholder.typicode.com/pos ...

Added by davidp on Mon, 14 Feb 2022 14:18:45 +0200

WinForm application interface development practical tutorial - realize regular email sending & shutdown processing

When we collect specific data, it often takes a long time. Sometimes, because of some things, it is impossible to wait for the results in front of the computer for a long time, so the program needs to automatically send us e-mail and other notices after a period of time, and execute exit program or shutdown and other aftercare work to save reso ...

Added by magicrobotmonkey on Mon, 14 Feb 2022 03:41:26 +0200