Java 如何在android中调用方法以便能够运行代码

我想在Android中创建一个简单的计算器，以我的方式，我在调用一个我已经声明过的函数时出错。这里有没有安卓专家可以帮我

public class CalculatorActivity extends AppCompatActivity {

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

    //Start my method

    public void calculator(View v) {
        Button btn0 = (Button) findViewById(R.id.btn0);
        Button btn1 = (Button) findViewById(R.id.btn1);
        Button btn2 = (Button) findViewById(R.id.btn2);
        Button btn3 = (Button) findViewById(R.id.btn3);
        Button btn4 = (Button) findViewById(R.id.btn4);
        Button btn5 = (Button) findViewById(R.id.btn5);
        Button btn6 = (Button) findViewById(R.id.btn6);
        Button btn7 = (Button) findViewById(R.id.btn7);

        TextView textViewResult = (TextView) findViewById(R.id.textView);

        if (btn0.isPressed() == true) {

            textViewResult.setText(textViewResult + "0");
        } else if (btn1.isPressed() == true) {
            textViewResult.setText(textViewResult + "1");

        }

    }
       //End my method

    //I want to call that fucntion, and i get an error
    calculator();


}

---

您应该在

OnCreate（）中调用该方法

试试这个

public class CalculatorActivity extends AppCompatActivity {

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

    //Start my method

    public void calculator() {
        Button btn0 = (Button) findViewById(R.id.btn0);
        Button btn1 = (Button) findViewById(R.id.btn1);
        Button btn2 = (Button) findViewById(R.id.btn2);
        Button btn3 = (Button) findViewById(R.id.btn3);
        Button btn4 = (Button) findViewById(R.id.btn4);
        Button btn5 = (Button) findViewById(R.id.btn5);
        Button btn6 = (Button) findViewById(R.id.btn6);
        Button btn7 = (Button) findViewById(R.id.btn7);

        TextView textViewResult = (TextView) findViewById(R.id.textView);

        if (btn0.isPressed() == true) {

            textViewResult.setText(textViewResult + "0");
        } else if (btn1.isPressed() == true) {
            textViewResult.setText(textViewResult + "1");

        }

    }
       //End my method
}

使用以下代码：

public class CalculatorActivity extends AppCompatActivity {

        @Override
        protected void onCreate(Bundle savedInstanceState) {
            super.onCreate(savedInstanceState);
            setContentView(R.layout.activity_calculator);
        //I want to call that fucntion, and i get an error
        calculator();
        }

        //Start my method

        public void calculator() {
            Button btn0 = (Button) findViewById(R.id.btn0);
            Button btn1 = (Button) findViewById(R.id.btn1);
            Button btn2 = (Button) findViewById(R.id.btn2);
            Button btn3 = (Button) findViewById(R.id.btn3);
            Button btn4 = (Button) findViewById(R.id.btn4);
            Button btn5 = (Button) findViewById(R.id.btn5);
            Button btn6 = (Button) findViewById(R.id.btn6);
            Button btn7 = (Button) findViewById(R.id.btn7);

            TextView textViewResult = (TextView) findViewById(R.id.textView);

            if (btn0.isPressed() == true) {

                textViewResult.setText(textViewResult + "0");
            } else if (btn1.isPressed() == true) {
                textViewResult.setText(textViewResult + "1");

            }

        }
           //End my method
    }

在onCreate（）方法中调用calculator（）方法；在onCreate（）中

现在要开始使用计算器了
use calculator（）；内部onCreate.call
calculator（）在您的
onCreate
计算器（视图v）
中需要视图作为参数。您缺少它。此用户提出的第一个问题可能与此重复。他问了一个简单的问题。我不确定为什么这个问题被否决了。也许这类似于另一个问题，但新用户可能无法找到它们。StackOverflow应该是一个新来者可以提问并获得答案的地方。也许关于如何在将来改进问题的建设性意见比否决此用户的第一个问题更有用。错误出现时说“calculator活动中的calculator（View）不能应用于（）”更改此行public void calculator（）更改此应添加返回类型？作为公共int计算器（）你到底在做什么，兄弟？我只是想用多种方式调用这个方法。无论何时何地，我想调用calculator（）方法时，都会突出显示一个错误！：（@Abdirahman Looskey使用此代码。调用方法很简单。
public class CalculatorActivity extends AppCompatActivity {

        @Override
        protected void onCreate(Bundle savedInstanceState) {
            super.onCreate(savedInstanceState);
            setContentView(R.layout.activity_calculator);
        //I want to call that fucntion, and i get an error
        calculator();
        }

        //Start my method

        public void calculator() {
            Button btn0 = (Button) findViewById(R.id.btn0);
            Button btn1 = (Button) findViewById(R.id.btn1);
            Button btn2 = (Button) findViewById(R.id.btn2);
            Button btn3 = (Button) findViewById(R.id.btn3);
            Button btn4 = (Button) findViewById(R.id.btn4);
            Button btn5 = (Button) findViewById(R.id.btn5);
            Button btn6 = (Button) findViewById(R.id.btn6);
            Button btn7 = (Button) findViewById(R.id.btn7);

            TextView textViewResult = (TextView) findViewById(R.id.textView);

            if (btn0.isPressed() == true) {

                textViewResult.setText(textViewResult + "0");
            } else if (btn1.isPressed() == true) {
                textViewResult.setText(textViewResult + "1");

            }

        }
           //End my method
    }

   public class CalculatorActivity extends AppCompatActivity {

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

    //Start my method

    public void calculator(View v) {
        Button btn0 = (Button) findViewById(R.id.btn0);
        Button btn1 = (Button) findViewById(R.id.btn1);
        Button btn2 = (Button) findViewById(R.id.btn2);
        Button btn3 = (Button) findViewById(R.id.btn3);
        Button btn4 = (Button) findViewById(R.id.btn4);
        Button btn5 = (Button) findViewById(R.id.btn5);
        Button btn6 = (Button) findViewById(R.id.btn6);
        Button btn7 = (Button) findViewById(R.id.btn7);

        TextView textViewResult = (TextView) findViewById(R.id.textView);

        if (btn0.isPressed() == true) {

            textViewResult.setText(textViewResult + "0");
        } else if (btn1.isPressed() == true) {
            textViewResult.setText(textViewResult + "1");

        }

    }
}