Question

我在Android应用程序上使用的函数有点问题。功能不是太难，它只是一个带有两个随机整数的简单计算。问题是我有一个标签，我想将文本更改为“问题”，以便用户可以解决它。我知道这个功能有问题，但我无法弄清楚是什么。我最接近的猜测是返回部分是错误的（因为它是空的），但到目前为止我无法解决它。

这是我的代码：

import java.util.Random;
import android.app.Activity;
import android.os.Bundle;
import android.view.View;
import android.view.View.OnClickListener;
import android.widget.TextView;

public class Game extends Activity implements OnClickListener {

private static final String TAG = "Game";

int game[];

public static final String KEY_DIFFICULTY = "com.example.coursework1.dificulty";

public static final int DIFFICULTY_NOVICE = 0;
public static final int DIFFICULTY_EASY = 1;
public static final int DIFFICULTY_MEDIUM = 2;
public static final int DIFFICULTY_GURU = 3;

protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.game);

    int diff = getIntent().getIntExtra(KEY_DIFFICULTY, DIFFICULTY_NOVICE);
    game = getGame(diff);


}

public int[] getGame(int diff) {
    // TODO Auto-generated method stub
    String operators [] =  {"+","-","*","/"};
    Random op1, op2, op3, op4, op5, op6;
    if(diff == getIntent().getIntExtra(KEY_DIFFICULTY, DIFFICULTY_NOVICE)){
        op1 = new Random();
        op2 = new Random();
        int operator = new Random().nextInt(operators.length);
        String random = (operators[operator]);
        int generate1 = op1.nextInt(10);
        int generate2 = op2.nextInt(10);
        int operation;
        if(random == "+"){
            operation = generate1 + generate2;
            TextView setProblemToView = (TextView) findViewById(R.id.problem);
            setProblemToView.setText("generate1" + random + "generate2");
        }
    }


    return null;
}

@Override
public void onClick(View arg0) {
    // TODO Auto-generated method stub
}
}

Answer 1

为什么在必须返回时使用int ruturn总是为null？像这样使用它：

public void getGame(int diff) {

    String operators [] =  {"+","-","*","/"};
    Random op1, op2, op3, op4, op5, op6;
    if(diff == getIntent().getIntExtra(KEY_DIFFICULTY, DIFFICULTY_NOVICE)){
        op1 = new Random();

        int operator = new Random().nextInt(operators.length);
        String random = (operators[operator]);
        int generate1 = op1.nextInt(10);
        int generate2 = op1.nextInt(10);
        int operation;
        if(  "+".equalsIgnoreCase(random) ){
            operation = generate1 + generate2;
            TextView setProblemToView = (TextView) findViewById(R.id.problem);
            setProblemToView.setText("generate1" + random + "generate2");
        }
    }

}

并将其称为：

getGame(diff);

我的修改中解决了相同的随机问题，请查看that了解更多

功能在android上运行不正常

1 个答案: