Development error notes

development environment IDE

Android Studio Environmental error

• 1. Error prompt that the resource file referenced by the layout does not exist

Caused by: android.content.res.Resources$NotFoundException

Caused by: org.xmlpull.v1.XmlPullParserException: 
Binary XML file line #8<gradient> tag requires 'angle' attribute to be a multiple of 45

   There is one bg xml file , There is a gradient configuration gradient One of them angle Property is assigned to 128, When reporting an error , The main idea is angle The value of must be 45 Multiple , Changed , The problem is solved in an instant . This problem deserves in-depth analysis , Look at the source code related to error reporting , A little clearer .

• 2.R Resource access is red , But it does not affect the normal operation of the program
     You cannot click to view the referenced resource file , Tried some online methods , Doesn't work , So it's upgraded as Version of ,from 4.2.2 to arctic fox, When the upgrade is complete R There is no problem with the resource file , You can click and jump normally , It's not red anymore .
     However, there are new problems , That is, the layout file preview appears fuzzy and the constraint position display is inaccurate , It is accurate after operation , I wanted to be demoted to 4.x edition , Then I searched as Of archive Version history , Found an updated Bumblebee bumblebee preview beta1, So I upgraded , Temporarily solved the problem .

Android Coding errors

1.RecyclerView item xml Layout match_parent Level not full

   The root layout uses ConstraintLayout and LinearLayout All have this problem , But with RelativeLayout There is no such problem . A search later found that , Originally in onCreateViewHolder Method inside inflate The layout will be methodical viewParent As inflate Methodical roo Parameters can completely solve this problem . Debugging found this viewParent yes RecyclerView.

2. The data format of the string array returned by the server

   A picture returned by the server url Array json

{
    
  imgs:"["http://xxx.jpg","http://xxy.jpg"]"
}

This situation is used in Gson go to Bean When ,Bean Medium imgs Can only be String type , Otherwise, the conversion will report an error , This situation gets imgs After the string , It also needs to be parsed manually , The picture url Add one by one to List In the container , A lot more redundant code , Very inelegant . The server needs to place ( Double quotes ) Get rid of ,

{
    
  imgs:["http://xxx.jpg","http://xxy.jpg"]
}

such ,Bean Medium imgs Can be defined as List<String> or MutableList<String>, The conversion tool can be directly converted to carry url Of List Containers , Very elegant .