Question

我正在尝试创建一个应用程序，根据用户指定的范围生成随机数在尝试切换到该片段之前，我遇到了一些问题，它会使应用程序崩溃，但这已经解决，因为onClickListener位于错误的位置。
Logcat设置是详细和无过滤器。当应用程序崩溃时，没有任何内容出现，所以我对应用程序崩溃的原因感到非常困惑这是我第一次真正构建应用程序下面是相应的Fragment.java文件：

    package com.lava.ldc.randomnumbersapp;

import android.content.Context;
import android.net.Uri;
import android.os.Bundle;
import android.support.v4.app.Fragment;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.Button;
import android.widget.EditText;
import android.widget.RelativeLayout;
import android.widget.TextView;
import android.widget.Toast;

import java.util.Random;


/**
 * A simple {@link Fragment} subclass.
 * Activities that contain this fragment must implement the
 * {@link RandomNumberGeneratorFragment.OnFragmentInteractionListener} interface
 * to handle interaction events.
 * Use the {@link RandomNumberGeneratorFragment#newInstance} factory method to
 * create an instance of this fragment.
 */
public class RandomNumberGeneratorFragment extends Fragment {
    // TODO: Rename parameter arguments, choose names that match
    // the fragment initialization parameters, e.g. ARG_ITEM_NUMBER
    private static final String ARG_PARAM1 = "param1";
    private static final String ARG_PARAM2 = "param2";

    // TODO: Rename and change types of parameters
    private String mParam1;
    private String mParam2;

    private OnFragmentInteractionListener mListener;

    public RandomNumberGeneratorFragment() {
        // Required empty public constructor
    }

    /**
     * Use this factory method to create a new instance of
     * this fragment using the provided parameters.
     *
     * @param param1 Parameter 1.
     * @param param2 Parameter 2.
     * @return A new instance of fragment RandomNumberGeneratorFragment.
     */
    // TODO: Rename and change types and number of parameters
    public static RandomNumberGeneratorFragment newInstance(String param1, String param2) {
        RandomNumberGeneratorFragment fragment = new RandomNumberGeneratorFragment();
        Bundle args = new Bundle();
        args.putString(ARG_PARAM1, param1);
        args.putString(ARG_PARAM2, param2);
        fragment.setArguments(args);
        return fragment;

    }

    EditText start;
    EditText end;
    Button btnGenerate;
    TextView randNum;

    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);

    }

    @Override
    public void onResume() {
        super.onResume();

}

@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
                         Bundle savedInstanceState) {
    // Inflate the layout for this fragment
    View view = (RelativeLayout) inflater.inflate(R.layout.fragment_random_number_generator, container, false);
    bindView(view);
    btnGenerate = (Button) view.findViewById(R.id.buttonGen);
    btnGenerate.setOnClickListener(new View.OnClickListener(){
        @Override
        public void onClick(View v){
            int min = Integer.parseInt(start.getText().toString());
            int max = Integer.parseInt(end.getText().toString());
            Random random = new Random();


            if(min>max){
                Toast toast = new Toast(getActivity().getApplicationContext());
                Toast.makeText(getActivity().getApplicationContext(), "The minimum range value you entered is larger then the maximum range value!", Toast.LENGTH_SHORT).show();
            }
            double randomMultiplier = random.nextDouble();
            long range = (long)max - (long)min + 1;
            int randomNumber = (int)((long)(range * randomMultiplier) + min);
            randNum.setText(randomNumber);
        }
    });
    //Initiated Broadcast receiver
    return view;

}

private void bindView(View view){
        start = (EditText) view.findViewById(R.id.start);
        end = (EditText) view.findViewById(R.id.end);

        randNum = (TextView) view.findViewById(R.id.randomNumber);
}

// TODO: Rename method, update argument and hook method into UI event
public void onButtonPressed(Uri uri) {
    if (mListener != null) {
        mListener.onFragmentInteraction(uri);
    }
}

@Override
public void onAttach(Context context) {
    super.onAttach(context);
    if (context instanceof OnFragmentInteractionListener) {
        mListener = (OnFragmentInteractionListener) context;
    } else {

    }
}

@Override
public void onDetach() {
    super.onDetach();
    mListener = null;
}

/**
 * This interface must be implemented by activities that contain this
 * fragment to allow an interaction in this fragment to be communicated
 * to the activity and potentially other fragments contained in that
 * activity.
 * <p>
 * See the Android Training lesson <a href=
 * "http://developer.android.com/training/basics/fragments/communicating.html"
 * >Communicating with Other Fragments</a> for more information.
 */
public interface OnFragmentInteractionListener {
    // TODO: Update argument type and name
    void onFragmentInteraction(Uri uri);
}}

下面是Fragment.xml文件：

    <RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context="com.lava.ldc.randomnumbersapp.RandomNumberGeneratorFragment">
    <ImageView
        android:id="@+id/imageView"
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        android:alpha="0.5"
        android:background="@drawable/rnbg" />

    <!-- TODO: Update blank fragment layout -->
    <TextView
        android:id="@+id/randomNumber"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="0"
        android:textColor="#000000"
        android:textSize="50sp"
        android:textStyle="bold"
        android:layout_marginBottom="85dp"
        android:layout_above="@+id/buttonGen"
        android:layout_centerHorizontal="true" />

    <Button
        android:id="@+id/buttonGen"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_marginBottom="82dp"
        android:elevation="24dp"
        android:text="Generate"
        android:layout_alignParentBottom="true"
        android:layout_centerHorizontal="true" />

    <EditText
        android:id="@+id/start"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:ems="10"
        android:hint="Enter lower range value"
        android:inputType="number"
        android:layout_above="@+id/end"
        android:layout_centerHorizontal="true"
        android:layout_marginBottom="30dp" />

    <TextView
        android:id="@+id/textView3"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_alignParentTop="true"
        android:layout_centerHorizontal="true"
        android:layout_marginTop="14dp"
        android:text="ENTER RANGE"
        android:textAlignment="center"
        android:textAllCaps="false"
        android:textColor="#000000"
        android:textSize="36sp"
        android:textStyle="bold" />

    <EditText
        android:id="@+id/end"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:ems="10"
        android:hint="Enter highest range value"
        android:inputType="number"
        android:layout_marginBottom="76dp"
        android:layout_above="@+id/randomNumber"
        android:layout_alignLeft="@+id/start"
        android:layout_alignStart="@+id/start" />

</RelativeLayout>

我只是不知道自己哪里出错了。所有帮助表示赞赏。

Answer 1

randNum.setText(randomNumber);可能导致问题。

它正在尝试使用randomNumber作为资源ID。

请参阅TextView.setText(int)的Android Framework文档作为参考。

您需要做的是将randomNumber转换为字符串。例如： randNum.setText(Integer.toString(randomNumber));

单击片段中的按钮后应用程序崩溃（logcat中没有错误！）

1 个答案: