Mobile Develop

The official mobile phone screen resolution ratio is the physical pixel ratio, such as ipone5 device resolution of 640*1136DP, the screen is 4 inches.1. Calculate PPIThe PPI, or pixels per inch, represents the number of pixels (Pixel) owned per inch.

android:screenorientation= "Portrait" >Generate secret key availableKeytool-genkey-v-keystore my-release-key.keystore-alias my-key-alias-keyalg rsa-keysize 2048-validity 10000Generate secret key availableKeytool-genkey-v-keystore

Next, you need to operate on main.js App.vue and so on.But there is a problem: what is main.js, and what does he do with it? What is App.vue for? What's the import from Main.js? What does Newvue ({}) do? What parameters do you need inside, and what

//normal program exits, will be in a few seconds to stop working;//To apply for a longer time, need to use// beginbackgroundtaskwithexpirationhandler//endbackgroundtask//must appear in pairs-(void) Applicationdidenterbackground: ( UIApplication *)

this. $route. query or this. $route. Params to receive Router-link passed parametersOne way to do this is to write this in the script tag. $router. Push (' pathname to jump '),About importing components, component jumps, and component

Idle time want to summarize the life cycle of this piece, create a new test project, first look atAppDelegate类方法的调用，在所有的方法中加入NSLog (@ "---%s---", __func__), printing method name-(BOOL) Application: (UIApplication *) application

manipulating databases with LitepalProblem: Add a database directly to the error exit 03-25 22:10:14.595 7094-7094/? E/memtrack:couldn ' t load memtrack module (No such file or directory) 03-25 22:10:14.595 7094-7094/? e/android.os.debug:failed to

Problem Source: Find All Numbers disappeared in an ArrayAfter a long time without a brush, I felt the brain was beginning to slow down, so I decided to regain the pleasure of brushing the question.Do not be too difficult at the beginning, choose

Design a FrameLayout (Kotlin) and framelayoutkotlin Split the parts and assemble the parts back and forth to familiarize yourself with the structure.FrameLayout features sub-views are stacked to display the size of FrameLayout in the order of

Introduction to ButterKnife and its principles (6) butterknife I analyzed the source code of ButterKnife and understood its implementation principle. Then I will apply the principle to practice.I. Custom annotations Only BindView annotations are

Register_chrdev, apiregister_chrdev Register_chrdev for kernel device driver APIs Register_chrdev is used to register a character device. The source code is analyzed as follows: static inline int register_chrdev (unsigned int major, const char *

Kernel device driver API _ register_chrdev_region, Kernel device driver API _ register_chrdev_region _ Register is used to register a separate master device number and a slave device number within a range. The source code analysis is as follows:

How to send a small program template message and send a small program template messageHow to send the applet template Message 1. Get access_token and user openid You need to request the corresponding interface in app. js. In fact, obtaining the

Based on the multi-entry Adapter encapsulated by BaseRecyclerViewAdapterHelper, it is convenient, convenient, and easy to maintain, I have already done a copy of toutiao.com. There are several la s in the News list: Project

String-related issues and notes in string. xml 1. If you need to display some strings with variables, such as "1st lesson? How can I help you write code? Section 2nd ", such a string can be defined in string. xml: Lesson % 1 $ d ?? % 2 $

ListView, ArrayAdapter, and arrayadapter Usage Summary of Listview adapter ArrayAdapter The following code uses the chat dialog Function Code 1. First define an object class as the wildcard of ArrayAdapter public class ChatlistviewData { public

How to dynamically refresh the friends list of XMPP, xmpp friends list 1. Brief Introduction I recently learned about the XMPP framework on ios and found a good mechanism. I can delete a user-specified friend on a client and then send a message to

The spin lock mutex and the spin lock mutex In Linux, there are four main operations related to spin locks.1. Define the spin lockSpinlock_t lock;2. initialize the spin lockSpin_lock_init (lock)This macro is used to dynamically initialize the spin

The same input jar is specified twice solution, specifiedtwice The same input jar is specified twice solution Android studio encountered such a problem during packaging Warning:Exception while processing task java.io.IOException: The same

Intent intent = new CallIntentBuilder (number ), Intent intent = new CallIntentBuilder (number) // 35. find it. The initial constructed data is number // 35. return to the initial start point final Intent intent = new CallIntentBuilder (number ).