标题栏在 Kotlin 中为空，如果我单击后退按钮

Question

如果我从活动 1--2 单击，那么我能够看到标题栏，但如果我从 2--1 单击返回，则标题栏值为空。我尝试了反向压制方法，但仍然没有帮助。我尝试了共享首选项和本地文件存储，但没有帮助。

Model Class:
class TestProject(val name: String,val location: String)
Main Class:     
private class ItemDetailAdapter(val TestProjectList:Array<TestProject>): RecyclerView.Adapter<ItemDetailViewHolder>()
{
override fun onBindViewHolder(p0: ItemDetailViewHolder, p1: Int) {
val TestProject=TestProjectList.get(p1)
p0?.customView?.TestProjectName?.text=TestProject.name
val TestProjectPicture=p0?.customView?.itemPicture
Picasso.get().load(TestProject.location).into(TestProjectPicture)
//Below code solved the Title Problem
p0?.Title=TestProject
}
override fun getItemCount(): Int {
return TestProjectList.size
}
override fun onCreateViewHolder(p0: ViewGroup, p1: Int): ItemDetailViewHolder {
val layoutInflater=LayoutInflater.from(p0?.context)
val customView=layoutInflater.inflate(R.layout.items_details,p0,false)
return ItemDetailViewHolder(customView)
}
}
class ItemDetailViewHolder(val customView:View,var Title: TestProject?=null):RecyclerView.ViewHolder(customView)
{
companion object {
val ITEM_TITLE_KEY="TestProject"
}
init {
customView.setOnClickListener {
val intent= Intent(customView.context,TestProjectMenuList::class.java)
intent.putExtra(ITEM_TITLE_KEY,Title?.name)
print("Printting Title :$Title?.name")
println("Hello Test $ITEM_TITLE_KEY")
customView.context.startActivity(intent)
println("Test")
}
}
TestProjectList Class:
val navBarTitle=intent.getStringExtra(MainClass.ItemDetailViewHolder.ITEM_TITLE_KEY)
supportActionBar?.title=navBarTitle

Answer 1

如果你确定

val navBarTitle=intent.getStringExtra(MainClass.ItemDetailViewHolder.ITEM_TITLE_KEY)

。有一个值，你可以把

val navBarTitle=intent.getStringExtra(MainClass.ItemDetailViewHolder.ITEM_TITLE_KEY)
supportActionBar?.title=navBarTitle

在恢复函数中。