简单的应用程序崩溃

Question

嘿所以我正在建立一本教育书籍的数学游戏。我问了一个类似的问题，卸载然后重新安装android帮助，相同的代码运行。现在，我在代码中得到了进一步的帮助，似乎无法找到错误。我觉得可能是我的setQuestion（）方法放在GameActivity.java的onClick方法中。此外，分数和级别元素不会更新，不确定问题是否属于该部分，但我觉得代码在更新之前就崩溃了。如果运行（在模拟器和我的手机上），直到用户选择一个答案，然后它崩溃。这是我的代码：

activity_main.xml中：

<?xml version="1.0" encoding="utf-8"?>
<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"
    android:paddingBottom="@dimen/activity_vertical_margin"
    android:paddingLeft="@dimen/activity_horizontal_margin"
    android:paddingRight="@dimen/activity_horizontal_margin"
    android:paddingTop="@dimen/activity_vertical_margin"
    tools:context="com.baylamafia.snzyt.mathgamechapter2.MainActivity">

<TextView
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:textAppearance="?android:attr/textAppearanceLarge"
    android:text="My Math Game"
    android:id="@+id/textView"
    android:layout_alignParentTop="true"
    android:layout_centerHorizontal="true"
    android:textSize="30sp" />

<ImageView
    android:layout_width="150dp"
    android:layout_height="150dp"
    android:id="@+id/imageView"
    android:layout_below="@+id/textView"
    android:layout_centerHorizontal="true"
    android:layout_marginTop="20dp" />

<Button
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:text="Play"
    android:id="@+id/buttonPlay"
    android:layout_centerVertical="true"
    android:layout_alignEnd="@+id/button2"
    android:layout_alignStart="@+id/button2" />

<Button
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:text="High Scores"
    android:id="@+id/button2"
    android:layout_below="@+id/buttonPlay"
    android:layout_centerHorizontal="true" />

<Button
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:text="Quit"
    android:id="@+id/button3"
    android:layout_below="@+id/button2"
    android:layout_alignStart="@+id/button2"
    android:layout_alignEnd="@+id/button2" />

MainActivity.java

package com.baylamafia.snzyt.mathgamechapter2;

import android.content.Intent;
import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.view.View;
import android.widget.Button;

public class MainActivity extends AppCompatActivity implements     View.OnClickListener{

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        Button buttonPlay = (Button)findViewById(R.id.buttonPlay);
        buttonPlay.setOnClickListener(this);
    }

    @Override
    public void onClick(View view) {
        Intent i;
        i = new Intent(this, GameActivity.class);
        startActivity(i);
    }
}

activity_game.xml

<?xml version="1.0" encoding="utf-8"?>
<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"
android:paddingBottom="@dimen/activity_vertical_margin"
android:paddingLeft="@dimen/activity_horizontal_margin"
android:paddingRight="@dimen/activity_horizontal_margin"
android:paddingTop="@dimen/activity_vertical_margin"
tools:context="com.baylamafia.snzyt.mathgamechapter2.GameActivity">

<TextView
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:textAppearance="?android:attr/textAppearanceLarge"
    android:text="2"
    android:id="@+id/textPartA"
    android:textSize="70sp"
    android:layout_alignParentTop="true"
    android:layout_alignParentStart="true"
    android:layout_alignBottom="@+id/textOperator" />

<TextView
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:textAppearance="?android:attr/textAppearanceLarge"
    android:text="x"
    android:id="@+id/textOperator"
    android:layout_alignParentTop="true"
    android:layout_centerHorizontal="true"
    android:textSize="70sp" />

<TextView
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:textAppearance="?android:attr/textAppearanceLarge"
    android:text="2"
    android:id="@+id/textPartB"
    android:textSize="70sp"
    android:layout_alignTop="@+id/textOperator"
    android:layout_alignParentEnd="true"
    android:layout_alignBottom="@+id/textOperator" />

<TextView
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:textAppearance="?android:attr/textAppearanceLarge"
    android:text="="
    android:id="@+id/textView2"
    android:textIsSelectable="true"
    android:layout_below="@+id/textOperator"
    android:layout_centerHorizontal="true"
    android:layout_marginTop="50dp" />

<Button
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:text="3"
    android:id="@+id/buttonChoice1"
    android:layout_alignTop="@+id/buttonChoice2"
    android:layout_toStartOf="@+id/buttonChoice2"
    android:textSize="40sp" />

<Button
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:text="4"
    android:id="@+id/buttonChoice2"
    android:layout_alignParentBottom="true"
    android:layout_centerHorizontal="true"
    android:layout_marginBottom="164dp"
    android:textSize="40sp" />

<Button
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:text="7"
    android:id="@+id/buttonChoice3"
    android:layout_alignTop="@+id/buttonChoice2"
    android:layout_toEndOf="@+id/buttonChoice2"
    android:textSize="40sp" />

<TextView
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:textAppearance="?android:attr/textAppearanceLarge"
    android:text="Score: 999"
    android:id="@+id/textScore"
    android:layout_alignParentBottom="true"
    android:layout_alignParentStart="true" />

<TextView
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:textAppearance="?android:attr/textAppearanceLarge"
    android:text="Level: 4"
    android:id="@+id/textLevel"
    android:layout_alignTop="@+id/textScore"
    android:layout_alignEnd="@+id/textPartB" />

GameActivity.java

package com.baylamafia.snzyt.mathgamechapter2;

import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.view.View;
import android.widget.Button;
import android.widget.TextView;
import android.widget.Toast;

import org.w3c.dom.Text;

import java.util.Random;

public class GameActivity extends AppCompatActivity implements     View.OnClickListener{

    int correctAnswer;
    Button buttonObjectChoice1;
    Button buttonObjectChoice2;
    Button buttonObjectChoice3;
    TextView textObjectPartA;
    TextView textObjectPartB;
    TextView textObjectScore;
    TextView textObjectLevel;
    int currentScore = 0;
    int currentLevel = 1;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_game);

    /*here we get a working object based on either the button or TextView class and base as well
    as link our new objects directly to the appropriate UI elements that we created previously
     */

        textObjectPartA =
                (TextView)findViewById(R.id.textPartA);

        textObjectPartB =
                (TextView)findViewById(R.id.textPartB);

        buttonObjectChoice1 =
                (Button)findViewById(R.id.buttonChoice1);

        buttonObjectChoice2 =
                (Button)findViewById(R.id.buttonChoice2);

        buttonObjectChoice3 =
                (Button)findViewById(R.id.buttonChoice3);

        buttonObjectChoice1.setOnClickListener(this);
        buttonObjectChoice2.setOnClickListener(this);
        buttonObjectChoice3.setOnClickListener(this);

        setQuestion();
    }

    void setQuestion(){
    //generate the parts of the question
        int numberRange = currentLevel * 3;
        Random randInt = new Random();

        int partA = randInt.nextInt(numberRange);
        partA++;

        int partB = randInt.nextInt(numberRange);
        partB++;

        correctAnswer = partA * partB;
        int wrongAnswer1 = correctAnswer-2;
        int wrongAnswer2 = correctAnswer+2;

        textObjectPartA.setText(""+partA);
        textObjectPartB.setText(""+partB);

    //set the multi choice button

        int buttonLayout = randInt.nextInt(3);
        switch (buttonLayout){

            case 0:
                buttonObjectChoice1.setText(""+correctAnswer);
                buttonObjectChoice2.setText(""+wrongAnswer1);
                buttonObjectChoice3.setText(""+wrongAnswer2);
                break;

            case 1:
                buttonObjectChoice1.setText(""+wrongAnswer1);
                buttonObjectChoice2.setText(""+correctAnswer);
                buttonObjectChoice3.setText(""+wrongAnswer2);
                break;

            case 2:
                buttonObjectChoice1.setText(""+wrongAnswer1);
                buttonObjectChoice2.setText(""+wrongAnswer2);
                buttonObjectChoice3.setText(""+correctAnswer);
                break;

        }
    }

    void updateScoreAndLevel (int answerGiven) {

        if(isCorrect(answerGiven)){
            for(int i = 1; i < currentLevel; i++){
                currentScore = currentScore + i;
            }

            currentLevel++;

        }else{
            currentScore = 0;
            currentLevel = 1;
        }

        textObjectScore.setText("Score: " + currentScore);
        textObjectLevel.setText("Level: " + currentLevel);
    }

    boolean isCorrect(int answerGiven){
        boolean correctTrueOrFalse;
        if (answerGiven == correctAnswer){
            Toast.makeText(getApplicationContext(), "Well done!",     Toast.LENGTH_LONG).show();
            correctTrueOrFalse=true;
        }else{
            Toast.makeText(getApplicationContext(), "Sorry", Toast.LENGTH_LONG).show();
            correctTrueOrFalse=false;
        }

        return correctTrueOrFalse;
    }

    @Override
    public void onClick(View view){
        int answerGiven = 0;
        switch (view.getId()) {

            case R.id.buttonChoice1:
                answerGiven = Integer.parseInt("" + buttonObjectChoice1.getText());
                break;

            case R.id.buttonChoice2:
                answerGiven = Integer.parseInt("" + buttonObjectChoice2.getText());
                break;

            case R.id.buttonChoice3:
                answerGiven = Integer.parseInt("" + buttonObjectChoice3.getText());
                break;

        }

        updateScoreAndLevel(answerGiven);
        setQuestion();
    }


}

的AndroidManifest.xml

<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
    package="com.baylamafia.snzyt.mathgamechapter2">

<application
    android:allowBackup="true"
    android:icon="@mipmap/ic_launcher"
    android:label="@string/app_name"
    android:supportsRtl="true"
    android:theme="@style/AppTheme">
    <activity android:name=".MainActivity">
        <intent-filter>
            <action android:name="android.intent.action.MAIN" />

            <category android:name="android.intent.category.LAUNCHER" />
        </intent-filter>
    </activity>
    <activity android:name=".GameActivity"></activity>
</application>

Answer 1

请勿在此处使用getApplicationContext：

 Toast.makeText(getApplicationContext(), "Well done!",     Toast.LENGTH_LONG).show();

使用this来使用当前活动：

 Toast.makeText(this, "Well done!",     Toast.LENGTH_LONG).show();

Difference between getContext() , getApplicationContext() , getBaseContext() and "this"

对于初学者来说，摆脱所有这些无关紧要的""+他们没有任何目的。您没有向字符串添加任何内容：

buttonObjectChoice1.setText(""+correctAnswer); 

answerGiven = Integer.parseInt("" + buttonObjectChoice1.getText());

也是这个

answerGiven = Integer.parseInt("" + buttonObjectChoice1.getText());

如果没有正确的输入，即<。>

，

将失败

此外，我不确定您在import org.w3c.dom.Text使用此内容。