Question

我有两个按钮：1和2.按钮1用于将数字从0增加到15，按钮2用于减少，输入是数字的当前值为0.

假设数字的初始值为= -1。然后我按下按钮1，数字将增加到1值（0）。如果我按5次，则当前数值为4.然后我按下按钮2，数值将从5

减少

For example, 
Button 1 press                         Button 2 press
0
1
2
3
4
                                               4
                                               3
                                               2
                                               ...

如果该值小于0，则禁用设置按钮2，如果该值大于15，则禁用设置按钮1。我使用下面的代码，但它不能很好地工作。你能告诉我发生了什么吗？

 int number=-1;
 public void onClickBtn1 (View v)
    {        
        number++;
        btn2.setEnabled(true);
        if(number>=16) {
            number = 16;
            btn1.setEnabled(false);
        }

        if(number<=15) {            
            Log.d("TAG", number);
        }
    }
    public void onClickBtn2 (View v)
    {
        btnTop.setEnabled(true);
        number--;
        if(number<=-1) {
            number =-1;
            btn2.setEnabled(false);
        }
        if(number>=0) {            
            Log.d("TAG",number);
        }
    }

更新：现在，按下按钮2时，我可以打印为0到5（按下按钮1）和（5到0）但是代码看起来很复杂，按钮禁用不起作用该数字超过15（＆lt; = 16），并且小于0（＆gt; = - 1）

我的代码是

int number=-1;
 public void onClickBtn1 (View v)
    {        
        btn2.setEnabled(true);
        if(number<=-1) {
            number =-1;
        }
        number++;
        if(number>=16) {
            number = 16;
            btn1.setEnabled(false);
        }
        if(number<=15) {
            Log.d("TAG",number);
        }
    }
    public void onClickBtn2 (View v)
    {
        btn1.setEnabled(true);

        if(number<=-1) {
            number =-1;
            btn2.setEnabled(false);
        }
        if(number>=16) {
            number = 15;
            btn1.setEnabled(false);
        }
        if(number>=0) {        
            Log.d("TAG",number);
        }
        number--;
    }

Answer 1

这是一个简单的逻辑。

it

它应该足以解决您的问题。如果有任何问题，请告诉我。

Answer 2

我认为这是你想要实现的目标。试试这个。

public void onClickBtn1 (View v)
{        
    number++;
    btn2.setEnabled(true);

    if(number==15) {
        btn1.setEnabled(false);
    }

    Log.d("TAG", number);
}

public void onClickBtn2 (View v)
{
    btn1.setEnabled(true);
    number--;
    if(number==0) {
        btn2.setEnabled(false);
    }           

    Log.d("TAG",number);
}

Answer 3

据我所知，您的问题可能就是解决方案

全局变量

public final String BUTTON1 = "button1", BUTTON2 = "button2";
TextView button2;
int number = 0;
String lastButtonClicked = "button1";

和您的buttonClickListeners

button1.setOnClickListener(new View.OnClickListener() {
    @Override
    public void onClick(View view) {
        button2.setEnabled(true);
        if (lastButtonClicked.equals(BUTTON1) && number < 15)
            number++;
        lastButtonClicked = BUTTON1;
        if (number == 15) {
            button1.setEnabled(false);
        }
        Log.d("TAG", "" + number);
    }
});
button2.setOnClickListener(new View.OnClickListener() {
    @Override
    public void onClick(View view) {
        button1.setEnabled(true);
        if (lastButtonClicked.equals(BUTTON2) && number > 0)
            number--;
        lastButtonClicked = BUTTON2;
        if (number == 0) {
            button2.setEnabled(false);
        }
        Log.d("TAG", "" + number);
    }
});
button2.setEnabled(false);
Log.d("TAG", "" + 0);

Answer 4

Button button1, button2;
int number = -1, initial = -1;

button2.setEnabled(false); // initially setting button2 disable

button1.setOnClickListener(new View.OnClickListener() {
        @Override
        public void onClick(View v) {


            if(number < 15) {
                number++;
            }
//this is because: If the value is smaller than 0, then set button 2 is disabled -> enabling if > 0
            if(number > 0) {
                button2.setEnabled(true);
            }

            if(number == 15){
                button1.setEnabled(false);  //because of range: from 0 to 15
            }

        }
    });

button2.setOnClickListener(new View.OnClickListener() {
        @Override
        public void onClick(View v) {

            button1.setEnabled(true);

// below condition is for: (Then I press the button 1, the number will increase to 1 value (0). If I press 5 times, the current number value is 4. Then I press the button 2, the values will decrease from 5)

//and initial value is -1 for once, as I think you didn't need to  check it later because range is 0-15 but initially you are taking -1.

            if(initial == -1){

                number = number - initial;
                initial = 0; // changed the value
            }


            if(number > 0) {
                number--;
            }

//as your range is 0-15, so can't be less than 0

            if(number == 0){
                button2.setEnabled(false);
            }
        }
    });

Answer 5

public class MainActivity extends AppCompatActivity {
int number = -1;
int total;
Button plus, minus;
TextView textViewTotal;
private static String TAG="MainActivity";

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

    plus = (Button) findViewById(R.id.btn_plus);
    minus = (Button) findViewById(R.id.btn_minus);
    textViewTotal = (TextView) findViewById(R.id.total);

    plus.setOnClickListener(new View.OnClickListener() {
        @Override
        public void onClick(View view) {
            total = number;
            if(number == 15) {
                plus.setEnabled(false);
            } else {
                number++;
                plus.setEnabled(true);
                textViewTotal.setText(String.valueOf(number));
            }
            if (number > 0) {
                minus.setEnabled(true);
            }
        }
    });

    minus.setOnClickListener(new View.OnClickListener() {
        @Override
        public void onClick(View view) {
            total = number;
            if(number < -1) {
                minus.setEnabled(false);
                plus.setEnabled(true);
            } else {
                minus.setEnabled(true);
                plus.setEnabled(true);
                number --;
                textViewTotal.setText(String.valueOf(number+1));
                if (total == number) {
                    number--;
                    textViewTotal.setText(String.valueOf(number));
                }
            }
        }
    });
}

}

按按钮时如何增加/减少数量？

5 个答案: