android - 无法实例化 fragment (找不到 fragment 构造函数)

Question

我在某些设备上遇到了这个问题，并且在我的崩溃分析中遇到错误。当应用遇到 ANR 问题并且错误是

Unable to start activity ComponentInfo{com.qwykr.dryver.base/com.qwykr.dryver.base.activities.MainActivity}: android.support.v4.app.Fragment$InstantiationException: Unable to instantiate fragment com.qwykr.dryver.base.fragments.SlideFragment: could not find Fragment constructor

@Override
protected void onCreate(Bundle arg0) {
    // TODO Auto-generated method stub
    super.onCreate(arg0);
}

Slide 的构造函数是

  @SuppressLint("ValidFragment")
public SideMenuFragment(Context mContext) {
    this.mContext=mContext;
}

并且有时会出现 ANR，这是导致此问题的原因。有时它工作正常，有时它会导致问题

Answer 1

这个例子在 Kotlin 上，但你也可以在 Java 上做

abstract class BaseFragment : Fragment() {

    override fun onCreate(savedInstanceState: Bundle?) {
        super.onCreate(savedInstanceState)
    }

    override fun onViewCreated(view: View?, savedInstanceState: Bundle?) {
        super.onViewCreated(view, savedInstanceState)
    }

    override fun onDestroyView() {
        super.onDestroyView()
    }

    override fun onResume() {
        super.onResume()
    }
}

class ApproveFragment : BaseFragment() {

    companion object {
        fun newInstance(orderId: Int) = ApproveFragment().apply {
            arguments = Bundle(1).apply {
                putInt("ORDER_ID", orderId)
            }
        }
    }

    override fun onCreateView(
        inflater: LayoutInflater?,
        container: ViewGroup?,
        savedInstanceState: Bundle?
    ): View? {
        return inflater?.inflate(R.layout.fragment_approve, container, false)
    }

    override fun onViewCreated(view: View?, savedInstanceState: Bundle?) {
        super.onViewCreated(view, savedInstanceState)
    }
}