如何在Android的屏幕之间创建正确的导航

Question

I've looked enough and I did not find a solution to my problem. I have not found any solution in the android documentation (or maybe I did not understand). I have a simple android app, and when I press the back key, in maiActivity, the application can return to a previous screen when the expected behavior is to exit the application. I await a suggestion.

Answer 1

Just put this in your MainActivity :

override fun onBackPressed() {
    super.onBackPressed()
    finish()
}

Additionally, if you want to add an AlertDialog for the user to ask confirmation before exiting:

override fun onBackPressed() {
    AlertDialog.Builder(this)
        .setTitle("Exit Confirmation")
        .setMessage("Are you sure you want to exit?")
        .setNegativeButton(android.R.string.no, null)
        .setPositiveButton(android.R.string.yes) 
            { _, _ -> super.onBackPressed() }
        .create()
        .show()
    }
}

Answer 2

I guess I've known what you want to do. The correct operation is: when you jump to a activity by startActivity(yourIntent) , you should add finish() if you don't need the current activity any more. If you didn't add finish() , the default behavior is back to previous screen when you click back button in new activity.

You should manage your activity stack well.