LifecycleOwner com.xx.MainActivity@28b4e79 is attempting to register while current state is RESUMED.

Android api29中startActivityForResult提示已过时，应该变成registerForActivityResult，当替换成这个方法的时候，在跳转的时候（Activity的onStart方法之后）执行以下代码，

ActivityResultLauncher<Intent> intentActivityResultLauncher = registerForActivityResult(
        new ActivityResultContracts.StartActivityForResult(),
        result -> {
            if (result.getResultCode() == RESULT_OK) {
                //获取返回的结果
                String data = result.getData().getStringExtra("data");
                Toast.makeText(activity, data, Toast.LENGTH_SHORT).show();
            }
        });
 
Intent intent = new Intent(JumpPage.this, NewWordActivity.class);
intent.putExtra("userId", "xxx");
intentActivityResultLauncher.launch(intent);

然后就会报错（LifecycleOwner com.xx.MainActivity@28b4e79 is attempting to register while current state is RESUMED.）。

解决方法：这个registerForActivityResult方法要写在Activity的onCreate方法里（在Activity创建的时候就要创建出来，不能等到使用的时候再创建，不然会报错LifecycleOwner com.xx.MainActivity@28b4e79 is attempting to register while current state is RESUMED. LifecycleOwners must call register before they are STARTED.）。