关于Android中计算器的设计

最近需要完成一个简单计算器的设计，思索了之后完成了一下的设计。

1. 首先进行Java类的编写，实现计算中的相应从操作。
2. 进行页面的设计，（这里我编写了两个界面，普通和高级）。
3. 两个页面之间进行跳转。
4. 点击产生不同的操作结果。

• 首先进行主界面的设计：

• 进行高级界面的设计：

• Java类编写：

package k.caculator;

import java.math.BigDecimal;

/**
 * Created by Administrator on 2017/4/1.
 */
public class clu {
    BigDecimal number1;
    BigDecimal number2;

    //sub
    BigDecimal clulatesub(String h1,String h2){
        number1 = new BigDecimal(h1);
        number2 = new BigDecimal(h2);
        return number1.subtract(number2);
    }
    //add
    BigDecimal clulateadd(String h1,String h2){
        number1 = new BigDecimal(h1);
        number2 = new BigDecimal(h2);
        return number1.add(number2);
    }
    //multiply
    BigDecimal clulatemultiply(String h1,String h2){
        number1 = new BigDecimal(h1);
        number2 = new BigDecimal(h2);
        return number1.multiply(number2);
    }
    //divde
    BigDecimal clulatedivde(String h1,String h2){
        number1 = new BigDecimal(h1);
        number2 = new BigDecimal(h2);
        return number1.divide(number2);
    }
    //平方
    BigDecimal clulatem(String h1){
        number1 = new BigDecimal(h1);
        return number1.multiply(number1);
    }
    //阶乘
   double clulatex(String h1){
        int i = Integer.valueOf(h1).intValue();
        double result=1;
        while(i>=1){
            result = i*result;
            i--;
        }
        return result;
    }
    //sin
    double clulatesin(String h1){
        double i = Integer.valueOf(h1).intValue();
        double result=0;
        result = Math.sin(i);
        return result;
    }
    //cos
    double clulatecos(String h1){
        double i = Integer.valueOf(h1).intValue();
        double result=0;
        result = Math.cos(i);
        return result;
    }
    //tan
    double clulatetan(String h1){
        double i = Integer.valueOf(h1).intValue();
        double result=0;
        result = Math.tan(i);
        return result;
    }
}

• Java文件编写。

package k.caculator;
import android.content.Intent;
import android.os.Bundle;
import android.os.Handler;
import android.os.Message;
import android.support.v7.app.AppCompatActivity;
import android.view.KeyEvent;
import android.view.View;
import android.widget.Button;
import android.widget.TextView;
import android.widget.Toast;

import java.math.BigDecimal;

public class MainActivity extends AppCompatActivity implements View.OnClickListener{

    TextView rsText = null;  //显示器
    String  num1, num2;
    BigDecimal Result;  //计算结果
    int op = 0; //判断操作数，
    boolean isClickEqu = false; //判断是否按了“=”按钮
    clu haha = new clu();//定义类实例

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

        //默认软键盘不弹出
//        getWindow().setSoftInputMode(WindowManager.LayoutParams.SOFT_INPUT_STATE_HIDDEN);

        //让editText失去焦点，使用EditText的clearFocus方法
//        EditText edit = (EditText)findViewById(R.id.show);
//        edit.clearFocus();

//        //让软键盘始终不显示
//        EditText edit = (EditText)findViewById(R.id.show);
//        edit.setInputType(InputType.TYPE_NULL);

        //功能按钮
        rsText = (TextView) findViewById(R.id.show);
        Button b_delete = (Button) findViewById(R.id.delete);
        Button b_back = (Button) findViewById(R.id.back);
        Button b_jia = (Button) findViewById(R.id.jia);
        Button b_jian = (Button) findViewById(R.id.jian);
        Button b_cheng = (Button) findViewById(R.id.chen);
        Button b_chu = (Button) findViewById(R.id.chu);
        Button b_dengyu = (Button) findViewById(R.id.dengyu);
        Button b_dian = (Button) findViewById(R.id.dian);

        //高级按钮
        Button bt = (Button) findViewById(R.id.left);

        bt.setOnClickListener(new View.OnClickListener()
        {
            public void onClick(View v)
            {
                Intent intent = new Intent();
                intent.setClass(MainActivity.this,second.class);
                MainActivity.this.startActivity(intent);
            }
        });

        //数字按钮
        Button b0 = (Button) findViewById(R.id.b0);
        Button b1 = (Button) findViewById(R.id.b1);
        Button b2 = (Button) findViewById(R.id.b2);
        Button b3 = (Button) findViewById(R.id.b3);
        Button b4 = (Button) findViewById(R.id.b4);
        Button b5 = (Button) findViewById(R.id.b5);
        Button b6 = (Button) findViewById(R.id.b6);
        Button b7 = (Button) findViewById(R.id.b7);
        Button b8 = (Button) findViewById(R.id.b8);
        Button b9 = (Button) findViewById(R.id.b9);

        //listener
        rsText.setOnClickListener(this);
        b_delete.setOnClickListener(this);
        b_back.setOnClickListener(this);
        b_jia.setOnClickListener(this);
        b_jian.setOnClickListener(this);
        b_cheng.setOnClickListener(this);
        b_chu.setOnClickListener(this);
        b_dengyu.setOnClickListener(this);
        b_dian.setOnClickListener(this);

        b0.setOnClickListener(this);
        b1.setOnClickListener(this);
        b2.setOnClickListener(this);
        b3.setOnClickListener(this);
        b4.setOnClickListener(this);
        b5.setOnClickListener(this);
        b6.setOnClickListener(this);
        b7.setOnClickListener(this);
        b8.setOnClickListener(this);
        b9.setOnClickListener(this);
    }

    @Override
    public void onClick(View view) {
        switch (view.getId()) {
            //AC和back
            case R.id.back:
                String myStr = rsText.getText().toString();
                try {
                    rsText.setText(myStr.substring(0, myStr.length() - 1));
                } catch (Exception e) {
                    rsText.setText("");
                }
                break;
            case R.id.delete:
                rsText.setText(null);
                break;
            //b0--9
            case R.id.b0:
                if (isClickEqu) {
                    rsText.setText(null);
                    isClickEqu = false;
                }
                String myString = rsText.getText().toString();
                myString += "0";
                rsText.setText(myString);
                break;
            case R.id.b1:
                if (isClickEqu) {
                    rsText.setText(null);
                    isClickEqu = false;
                }
                String myString1 = rsText.getText().toString();
                myString1 += "1";
                rsText.setText(myString1);
                break;
            case R.id.b2:
                if (isClickEqu) {
                    rsText.setText(null);
                    isClickEqu = false;
                }
                String myString2 = rsText.getText().toString();
                myString2 += "2";
                rsText.setText(myString2);
                break;
            case R.id.b3:
                if (isClickEqu) {
                    rsText.setText(null);
                    isClickEqu = false;
                }
                String myString3 = rsText.getText().toString();
                myString3 += "3";
                rsText.setText(myString3);
                break;
            case R.id.b4:
                if (isClickEqu) {
                    rsText.setText(null);
                    isClickEqu = false;
                }
                String myString4 = rsText.getText().toString();
                myString4 += "4";
                rsText.setText(myString4);
                break;
            case R.id.b5:
                if (isClickEqu) {
                    rsText.setText(null);
                    isClickEqu = false;
                }
                String myString5 = rsText.getText().toString();
                myString5 += "5";
                rsText.setText(myString5);
                break;
            case R.id.b6:
                if (isClickEqu) {
                    rsText.setText(null);
                    isClickEqu = false;
                }
                String myString6 = rsText.getText().toString();
                myString6 += "6";
                rsText.setText(myString6);
                break;
            case R.id.b7:
                if (isClickEqu) {
                    rsText.setText(null);
                    isClickEqu = false;
                }
                String myString7 = rsText.getText().toString();
                myString7 += "7";
                rsText.setText(myString7);
                break;
            case R.id.b8:
                if (isClickEqu) {
                    rsText.setText(null);
                    isClickEqu = false;
                }
                String myString8 = rsText.getText().toString();
                myString8 += "8";
                rsText.setText(myString8);
                break;
            case R.id.b9:
                if (isClickEqu) {
                    rsText.setText(null);
                    isClickEqu = false;
                }
                String myString9 = rsText.getText().toString();
                myString9 += "9";
                rsText.setText(myString9);
                break;
            case R.id.dian:
                if (isClickEqu) {
                    rsText.setText(null);
                    isClickEqu = false;
                }
                String myString0 = rsText.getText().toString();
                myString0 += ".";
                rsText.setText(myString0);
                break;
            //b+,-,=
            case R.id.jia:
                String myStringAdd = rsText.getText().toString();
                if (myStringAdd.equals(null)) {
                    return;
                }
                num1 = myStringAdd;
                rsText.setText(null);
                op = 1;
                isClickEqu = false;
                break;
            case R.id.jian:
                String myStringSub = rsText.getText().toString();
                if (myStringSub.equals(null)) {
                    return;
                }
                num1 = myStringSub;
                rsText.setText(null);
                op = 2;
                isClickEqu = false;
                break;
            case R.id.chen:
                String myStringMul = rsText.getText().toString();
                if (myStringMul.equals(null)) {
                    return;
                }
                num1 = myStringMul;
                rsText.setText(null);
                op = 3;
                isClickEqu = false;
                break;
            case R.id.chu:
                String myStringDiv = rsText.getText().toString();
                if (myStringDiv.equals(null)) {
                    return;
                }
                num1 = myStringDiv;
                rsText.setText(null);
                op = 4;
                isClickEqu = false;
                break;
            case R.id.dengyu:
                String myStringEqu = rsText.getText().toString();
                if (myStringEqu.equals(null)) {
                    return;
                }
                num2 = myStringEqu;
                rsText.setText(null);
                switch (op) {
                    case 0:
                        double i = Integer.valueOf(num2).intValue();
                        Result = BigDecimal.valueOf(i);
                        break;
                    case 1:
                        Result = haha.clulateadd(num1,num2);
                        break;
                    case 2:
                        Result = haha.clulatesub(num1,num2);;
                        break;
                    case 3:
                        Result = haha.clulatemultiply(num1,num2);;
                        break;
                    case 4:
                        double num2ch = Integer.valueOf(num2).intValue();
                        if(num2ch==0){
                            rsText.setText("格式输入错误！");
                            return;
                        }
                        Result = haha.clulatedivde(num1,num2);;
                        break;
                    default:
                        Result = BigDecimal.valueOf('0');
                        break;
                }
                rsText.setText(String.valueOf(Result));
                isClickEqu = true;
                break;
            default:
                break;
        }
    }

    //定义一个变量，来表示是否退出
    private static boolean isExit = false;
    Handler mHandler = new Handler() {
        public void handleMessage(Message msg) {
            super.handleMessage(msg);
            isExit = false;
        }
    };
    //点击两次返回键退出
    @Override
    public boolean onKeyDown(int keyCode, KeyEvent event) {
        if (keyCode == KeyEvent.KEYCODE_BACK) {
            exit();
            return false;
        }
        return super.onKeyDown(keyCode, event);
    }
    //点击两次返回键退出
    private void exit() {
        if (!isExit) {
            isExit = true;
            Toast.makeText(getApplicationContext(), "再按一次退出程序",
                    Toast.LENGTH_SHORT).show();
            // 利用handler延迟发送更改状态信息
            mHandler.sendEmptyMessageDelayed(0, 2000);
        } else {
            finish();
            System.exit(0);
        }
    }
}

//高级界面的Java文件

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

import java.math.BigDecimal;

public class second extends AppCompatActivity  implements View.OnClickListener{
    TextView rsText = null;  //显示器
    String  num1, num2;
    BigDecimal Result;  //计算结果
    int op = 0; //判断操作数，
    boolean isClickEqu = false; //判断是否按了“=”按钮
    clu haha = new clu();//定义类实例
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_second);

        //功能按钮
        rsText = (TextView) findViewById(R.id.show);
        Button b_clear = (Button) findViewById(R.id.clear);//不能够清除
        Button b_back = (Button) findViewById(R.id.back);
        Button b_m = (Button) findViewById(R.id.m);
        Button b_x = (Button) findViewById(R.id.jiechen);
        Button b_sin = (Button) findViewById(R.id.sin);
        Button b_cos = (Button) findViewById(R.id.cos);
        Button b_tan = (Button) findViewById(R.id.tan);
        Button b_dian = (Button) findViewById(R.id.dian);
        Button b_dengyu = (Button) findViewById(R.id.dengyu);

        //返回按钮
        Button b_re = (Button) findViewById(R.id.re);

        //返回按钮功能
        b_re.setOnClickListener(new View.OnClickListener()
        {
            public void onClick(View v)
            {
                Intent intent = new Intent();
                intent.setClass(second.this,MainActivity.class);
                second.this.startActivity(intent);
            }
        });

        //数字按钮
        Button b0 = (Button) findViewById(R.id.b0);
        Button b1 = (Button) findViewById(R.id.b1);
        Button b2 = (Button) findViewById(R.id.b2);
        Button b3 = (Button) findViewById(R.id.b3);
        Button b4 = (Button) findViewById(R.id.b4);
        Button b5 = (Button) findViewById(R.id.b5);
        Button b6 = (Button) findViewById(R.id.b6);
        Button b7 = (Button) findViewById(R.id.b7);
        Button b8 = (Button) findViewById(R.id.b8);
        Button b9 = (Button) findViewById(R.id.b9);

        //listener
        rsText.setOnClickListener(this);
        b_m.setOnClickListener(this);
        b_back.setOnClickListener(this);
        b_sin.setOnClickListener(this);
        b_cos.setOnClickListener(this);
        b_tan.setOnClickListener(this);
        b_x.setOnClickListener(this);
        b_dengyu.setOnClickListener(this);
        b_dian.setOnClickListener(this);

        b0.setOnClickListener(this);
        b1.setOnClickListener(this);
        b2.setOnClickListener(this);
        b3.setOnClickListener(this);
        b4.setOnClickListener(this);
        b5.setOnClickListener(this);
        b6.setOnClickListener(this);
        b7.setOnClickListener(this);
        b8.setOnClickListener(this);
        b9.setOnClickListener(this);
    }

    @Override
    public void onClick(View view) {
        switch (view.getId()) {
            //AC和back
            case R.id.back:
                String myStr = rsText.getText().toString();
                try {
                    rsText.setText(myStr.substring(0, myStr.length() - 1));
                } catch (Exception e) {
                    rsText.setText("");
                }
                break;
            case R.id.clear:
                rsText.setText(null);
                break;
            //b0--9
            case R.id.b0:
                if (isClickEqu) {
                    rsText.setText(null);
                    isClickEqu = false;
                }
                String myString = rsText.getText().toString();
                myString += "0";
                rsText.setText(myString);
                break;
            case R.id.b1:
                if (isClickEqu) {
                    rsText.setText(null);
                    isClickEqu = false;
                }
                String myString1 = rsText.getText().toString();
                myString1 += "1";
                rsText.setText(myString1);
                break;
            case R.id.b2:
                if (isClickEqu) {
                    rsText.setText(null);
                    isClickEqu = false;
                }
                String myString2 = rsText.getText().toString();
                myString2 += "2";
                rsText.setText(myString2);
                break;
            case R.id.b3:
                if (isClickEqu) {
                    rsText.setText(null);
                    isClickEqu = false;
                }
                String myString3 = rsText.getText().toString();
                myString3 += "3";
                rsText.setText(myString3);
                break;
            case R.id.b4:
                if (isClickEqu) {
                    rsText.setText(null);
                    isClickEqu = false;
                }
                String myString4 = rsText.getText().toString();
                myString4 += "4";
                rsText.setText(myString4);
                break;
            case R.id.b5:
                if (isClickEqu) {
                    rsText.setText(null);
                    isClickEqu = false;
                }
                String myString5 = rsText.getText().toString();
                myString5 += "5";
                rsText.setText(myString5);
                break;
            case R.id.b6:
                if (isClickEqu) {
                    rsText.setText(null);
                    isClickEqu = false;
                }
                String myString6 = rsText.getText().toString();
                myString6 += "6";
                rsText.setText(myString6);
                break;
            case R.id.b7:
                if (isClickEqu) {
                    rsText.setText(null);
                    isClickEqu = false;
                }
                String myString7 = rsText.getText().toString();
                myString7 += "7";
                rsText.setText(myString7);
                break;
            case R.id.b8:
                if (isClickEqu) {
                    rsText.setText(null);
                    isClickEqu = false;
                }
                String myString8 = rsText.getText().toString();
                myString8 += "8";
                rsText.setText(myString8);
                break;
            case R.id.b9:
                if (isClickEqu) {
                    rsText.setText(null);
                    isClickEqu = false;
                }
                String myString9 = rsText.getText().toString();
                myString9 += "9";
                rsText.setText(myString9);
                break;
            case R.id.dian:
                if (isClickEqu) {
                    rsText.setText(null);
                    isClickEqu = false;
                }
                String myString0 = rsText.getText().toString();
                myString0 += ".";
                rsText.setText(myString0);
                break;
            case R.id.m:
                String myStringm = rsText.getText().toString();
                if (myStringm.equals(null)) {
                    return;
                }
                num1 = myStringm;
                rsText.setText(myStringm + "^2");
                op = 1;
                isClickEqu = false;
                break;
            case R.id.jiechen:
                String myStringx = rsText.getText().toString();
                if (myStringx.equals(null)) {
                    return;
                }
                num1 = myStringx;
                rsText.setText(myStringx + "!");
                op = 2;
                isClickEqu = false;
                break;
            case R.id.sin:
                String myStringsin = rsText.getText().toString();
                if (myStringsin.equals(null)) {
                    return;
                }
                num1 = myStringsin;
                rsText.setText("sin("+myStringsin + ")");
                op = 3;
                isClickEqu = false;
                break;
            case R.id.cos:
                String myStringcos = rsText.getText().toString();
                if (myStringcos.equals(null)) {
                    return;
                }
                num1 = myStringcos;
                rsText.setText("cos("+myStringcos + ")");
                op = 4;
                isClickEqu = false;
                break;
            case R.id.tan:
                String myStringtan = rsText.getText().toString();
                if (myStringtan.equals(null)) {
                    return;
                }
                num1 = myStringtan;
                rsText.setText("cos("+myStringtan + ")");
                op = 5;
                isClickEqu = false;
                break;
            case R.id.dengyu:
                String myStringEqu = rsText.getText().toString();
                if (myStringEqu.equals(null)) {
                    return;
                }
                num2 = myStringEqu;
                rsText.setText(null);
                switch (op) {
                    case 0://本身
                        double i = Integer.valueOf(num2).intValue();
                        Result = BigDecimal.valueOf(i);
                        break;
                    case 1://平方
                        Result = haha.clulatem(num1);
                        break;
                    case 2://阶乘
                        rsText.setText(String.valueOf(haha.clulatex(num1)));
                        return;
                    case 3:			   			             	rsText.setText(String.valueOf(haha.clulatesin(num1)));;
    	return;
case 4: 
    	rsText.setText(String.valueOf(haha.clulatecos(num1)));
    	return;
	case 5:
	rsText.setText(String.valueOf(haha.clulatetan(num1)));
    	return;
                    default:
                        Result = BigDecimal.valueOf('0');
                        break;
                }
                rsText.setText(String.valueOf(Result));
                isClickEqu = true;
                break;
            default:
                break;
        }
    }
}

经过这样的设计之后就能够得到一个能够进行简单计算的计算器。

由于本人也是初学者，所以有得很么不对的地方，还请各位大牛不吝赐教。如果需要源码的朋友，请私信我！