kotlin应用程序中的数据绑定中有错误

Question

[我正在尝试在我的kotlin android应用中绑定数据，我在codelab Link to Codelab上关注了本教程，我做的所有事情都一样。

但是在ActivityMainBinding文件中导入MainActitvity.kt时，ide继续以红色文本显示错误。

我确实在这里在应用程序级别的gradle文件中启用了dataBinding，>

dataBinding {
        enabled = true
    }
这里我已经导入并初始化了dataBinding

import android.content.Context
import android.databinding.DataBindingUtil
import android.hardware.input.InputManager
import android.support.v7.app.AppCompatActivity
import android.os.Bundle
import android.view.View
import android.view.inputmethod.InputMethodManager
import android.widget.Button
import android.widget.EditText
import android.widget.TextView
//import kotlinx.android.synthetic.main.activity_main.*
import com.example.aboutme.databinding.ActivityMainBinding

class MainActivity : AppCompatActivity() {

    private lateinit var binding: ActivityMainBinding

    override fun onCreate(savedInstanceState: Bundle?) {
        super.onCreate(savedInstanceState)
        //setContentView(R.layout.activity_main)
        binding = DataBindingUtil.setContentView(this, R.layout.activity_main)

        binding.done_button.setOnClickListener{
            addNickname(it)
        }
    }

    private fun addNickname(view: View) {


        binding.apply{
            nickname_text.text = binding.nickname_edit.text
            invalidateAll()
            nickname_edit.visibility = View.GONE
            done_button.visibility = View.GONE
            nickname_text.visibility = View.VISIBLE
        }



        //Hide the Keyboard

        val inn = getSystemService(Context.INPUT_METHOD_SERVICE) as InputMethodManager
        inn.hideSoftInputFromWindow(view.windowToken, 0)

    }
}
无论如何我尝试构建gradle时遇到错误。我想试试看。

Compilation Error
我是Android新手。

activity_main.xml

<?xml version="1.0" encoding="utf-8"?>
<layout
        xmlns:android="http://schemas.android.com/apk/res/android"
        xmlns:app="http://schemas.android.com/apk/res-auto"

tools：context =“。MainActivity”>

        android:orientation="vertical"
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        >


    <TextView
            android:text="@string/name"
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            android:id="@+id/textView"
            style="@style/name_style"/>
    <ImageView
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            app:srcCompat="@android:drawable/btn_star_big_on"
            android:id="@+id/imageView2"/>
    <EditText
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            android:inputType="textPersonName"
            android:ems="10"
            android:id="@+id/nickname_edit" style="@style/name_style" android:hint="what is your nickname"/>
    <Button
            android:text="Done"
            android:layout_gravity="center_horizontal"
            style="@style/Widget.AppCompat.Button.Colored"
            android:layout_width="match_parent"
            android:layout_height="wrap_content" android:id="@+id/done_button"/>
    <TextView
            android:layout_width="match_parent"
            android:layout_height="wrap_content" android:id="@+id/nickname_text" style="@style/name_style"
            android:visibility="gone"/>
    <ScrollView
            android:id="@+id/bio_scroll"
            android:layout_width="match_parent"
            android:layout_height="match_parent">

        <TextView
                style="@style/name_style"
                android:text="@string/bio"
                android:layout_width="match_parent"
                android:layout_height="wrap_content"
                android:id="@+id/bio_text"
                android:lineSpacingMultiplier="1.2"
        />
    </ScrollView>

</LinearLayout>
</layout>
日志错误

Unresolved reference. None of the following candidates is applicable because of receiver type mismatch:
public val Activity.done_button: Button! defined in kotlinx.android.synthetic.main.activity_main
public val Dialog.done_button: Button! defined in kotlinx.android.synthetic.main.activity_main
public val android.app.Fragment.done_button: Button! defined in kotlinx.android.synthetic.main.activity_main
public val android.support.v4.app.Fragment.done_button: Button! defined in kotlinx.android.synthetic.main.activity_main 
Unresolved reference: it    
Unresolved reference. None of the following candidates is applicable because of receiver type mismatch:
public val Activity.nickname_edit: EditText! defined in kotlinx.android.synthetic.main.activity_main
public val Dialog.nickname_edit: EditText! defined in kotlinx.android.synthetic.main.activity_main
public val android.app.Fragment.nickname_edit: EditText! defined in kotlinx.android.synthetic.main.activity_main
public val android.support.v4.app.Fragment.nickname_edit: EditText! defined in kotlinx.android.synthetic.main.activity_main

> Task :app:buildInfoGeneratorDebug 

我正在尝试在我的kotlin android应用程序中绑定数据，我在codelab上关注本教程链接到Codelab，我所做的一切都相同。但是，当在MainActitvity.kt文件中导入ActivityMainBinding时ide ...

Answer 1

将名称空间声明移到您的布局标签，然后删除重复项。进行更改后，它应该看起来像这样：

Answer 2

1）您需要在gradle.wrapper-properties中添加distributionUrl以获取最新的android studio版本。您的网址必须为