如何使用Jetpack库保存活动实例

implementation "androidx.lifecycle:lifecycle-viewmodel-ktx:2.4.0"

import androidx.lifecycle.ViewModel

class MyViewModel : ViewModel() {
    // 在这里定义需要保存的数据和状态
}

import androidx.activity.viewModels

class MyActivity : AppCompatActivity() {
    private val viewModel: MyViewModel by viewModels()

    // 在这里使用viewModel来保存和管理数据
}

import androidx.lifecycle.SavedStateHandle
import androidx.lifecycle.ViewModel

class MyViewModel(private val savedStateHandle: SavedStateHandle) : ViewModel() {
    private val INSTANCE_STATE_KEY = "instance_state_key"

    fun saveInstanceState(instanceState: Bundle) {
        savedStateHandle.set(INSTANCE_STATE_KEY, instanceState)
    }

    fun restoreInstanceState(): Bundle? {
        return savedStateHandle.get(INSTANCE_STATE_KEY)
    }
}