Why wrong dozen code according to the book

CodePudding user response:

Corresponding control in your XML layout of id is what?" Button "and" editText "is the control id, you see activity_main. The XML file.

CodePudding user response:

The button and the editText didn't define it, as if kotlin without the findviewbyid need to install the plugin

CodePudding user response:

You didn't declare the Button and the EditText

CodePudding user response:

Do not need the findviewbyid kotlin, can be directly through the control id to access control, need a plug-in, but usually the new kotlin project automatically added, build the project. The gradle:

 classpath "org. Jetbrains. Kotlin: kotlin - gradle - plugin: 1.4.10" 

In the module build. Gradle:

 apply plugin: 'kotlin - android - extensions' 

If have been added to the plugin, it should be your XML file corresponding to the id of the control is not this, or did not import, Alt + enter. Where an error is
The import kotlinx. Android. Synthetic. Main. ${XML file name}. *