ViewModelProviders.of（FragmentActivity）获得（视图模型:: class.java）要求的活动，而不是在视图模型的get（）调用

Question

ViewModelProviders.of（本）获得（）失败了不可预见的原因这被称为从FragmentActivity继承我的主要活动。实际上，我对获得（）调用得到一个错误。该错误表示，它期待的活动，而不是一个视图模型这违背了文档。我已经清除无效缓存。我的猜测是，我有一个坏的进口或旧库版本莫名其妙

import androidx.appcompat.app.AppCompatActivity import android.os.Bundle import androidx.databinding.DataBindingUtil import androidx.lifecycle.ViewModelProviders import androidx.recyclerview.widget.LinearLayoutManager import androidx.recyclerview.widget.RecyclerView import com.apsoftware.urbandictionary.R

class DefinitionActivity : AppCompatActivity() {

    private lateinit var binding: ActivityPostListBinding
    private lateinit var viewModel: DefinitionActivity


    override fun onCreate(savedInstanceState: Bundle?) {
        super.onCreate(savedInstanceState)
        setContentView(R.layout.activity_main)
        binding = DataBindingUtil.setContentView(this, R.layout.activity_main)
        binding.postList.layoutManager = LinearLayoutManager(this, RecyclerView.VERTICAL, false)
        viewModel = ViewModelProviders.of(this).get(DefinitionViewModel::class.java)
        binding.viewModel = viewModel
    } }

implementation "org.jetbrains.kotlin:kotlin-stdlib-jdk7:$kotlin_version"
implementation 'androidx.appcompat:appcompat:1.1.0-alpha01'
implementation 'androidx.core:core-ktx:1.1.0-alpha04'
implementation 'androidx.constraintlayout:constraintlayout:1.1.3'
implementation 'com.google.android.material:material:1.0.0'
implementation "com.squareup.okhttp3:okhttp:3.12.0"
implementation "com.squareup.retrofit2:retrofit:2.5.0"
implementation "com.squareup.retrofit2:adapter-rxjava2:2.4.0"
implementation 'com.squareup.retrofit2:converter-moshi:2.5.0'
implementation 'com.squareup.moshi:moshi:1.6.0'
kapt 'com.android.databinding:compiler:3.1.4'
implementation "com.google.dagger:dagger:2.20"
kapt "com.google.dagger:dagger-compiler:2.11"
annotationProcessor 'com.google.dagger:dagger-compiler:2.11'
compileOnly "org.glassfish:javax.annotation:3.1.1"
implementation "io.reactivex.rxjava2:rxjava:2.2.2"
implementation "io.reactivex.rxjava2:rxandroid:2.0.2"
implementation "android.arch.lifecycle:extensions:1.1.1"

Answer 1

你声明

private lateinit var viewModel: DefinitionActivity

即，viewModel是DefinitionActivity的一个实例。这应该是一个DefinitionViewModel匹配你传递什么到get()。

Answer 2

更改

 private lateinit var viewModel: DefinitionActivity

至

 private lateinit var viewModel: DefinitionViewModel