Android——计算器

layout文件：

<?xml version="1.0" encoding="utf-8"?>
<GridLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:rowCount="6"
    android:columnCount="4"
    xmlns:tools="http://schemas.android.com/tools"
    tools:context="com.hanqi.testapp2.PractiseActivity5">
    <TextView
        android:layout_width="match_parent"
        android:layout_height="200dp"
        android:layout_columnSpan="4"
        android:gravity="bottom|right"
        android:id="@+id/tv_1"
        android:textSize="50sp"
        android:paddingRight="10dp"
        android:textColor="#0F0"/>
    <Button
        android:layout_width="0dp"
        android:layout_height="0dp"
        android:text="c"
        android:layout_columnWeight="1"
        android:layout_rowWeight="1"
        android:textSize="25sp"
        android:id="@+id/bt_c"/>
    <Button
        android:layout_width="0dp"
        android:layout_height="0dp"
        android:text="←"
        android:layout_columnWeight="1"
        android:layout_rowWeight="1"
        android:textSize="25sp"
        android:id="@+id/bt_tui"/>
    <Button
        android:layout_width="0dp"
        android:layout_height="0dp"
        android:text="÷"
        android:layout_columnWeight="1"
        android:layout_rowWeight="1"
        android:textSize="25sp"
        android:id="@+id/bt_chu"
        android:onClick="bt_chu_onClick"/>
    <Button
        android:layout_width="0dp"
        android:layout_height="0dp"
        android:text="×"
        android:layout_columnWeight="1"
        android:layout_rowWeight="1"
        android:textSize="25sp"
        android:id="@+id/bt_cheng"
        android:onClick="bt_cheng_onClick"/>
    <Button
        android:layout_width="0dp"
        android:layout_height="0dp"
        android:text="7"
        android:layout_columnWeight="1"
        android:layout_rowWeight="1"
        android:textSize="25sp"
        android:onClick="bt_onClick"
        android:id="@+id/bt7"/>
    <Button
        android:layout_width="0dp"
        android:layout_height="0dp"
        android:text="8"
        android:layout_columnWeight="1"
        android:layout_rowWeight="1"
        android:textSize="25sp"
        android:onClick="bt_onClick"
        android:id="@+id/bt8"/>
    <Button
        android:layout_width="0dp"
        android:layout_height="0dp"
        android:text="9"
        android:layout_columnWeight="1"
        android:layout_rowWeight="1"
        android:textSize="25sp"
        android:onClick="bt9_onClick"
        android:id="@+id/bt9"/>
    <Button
        android:layout_width="0dp"
        android:layout_height="0dp"
        android:text="－"
        android:layout_columnWeight="1"
        android:layout_rowWeight="1"
        android:textSize="25sp"
        android:id="@+id/bt_jian"
        android:onClick="bt_jian_onClick"/>
    <Button
        android:layout_width="0dp"
        android:layout_height="0dp"
        android:text="4"
        android:layout_columnWeight="1"
        android:layout_rowWeight="1"
        android:textSize="25sp"
        android:id="@+id/bt4"/>
    <Button
        android:layout_width="0dp"
        android:layout_height="0dp"
        android:text="5"
        android:layout_columnWeight="1"
        android:layout_rowWeight="1"
        android:textSize="25sp"
        android:id="@+id/bt5"/>
    <Button
        android:layout_width="0dp"
        android:layout_height="0dp"
        android:text="6"
        android:layout_columnWeight="1"
        android:layout_rowWeight="1"
        android:textSize="25sp"
        android:id="@+id/bt6"/>
    <Button
        android:layout_width="0dp"
        android:layout_height="0dp"
        android:text="＋"
        android:layout_columnWeight="1"
        android:layout_rowWeight="1"
        android:textSize="25sp"
        android:id="@+id/bt_jia"
        android:onClick="bt_jia_onClick"/>
    <Button
        android:layout_width="0dp"
        android:layout_height="0dp"
        android:text="1"
        android:layout_columnWeight="1"
        android:layout_rowWeight="1"
        android:textSize="25sp"
        android:id="@+id/bt1"/>
    <Button
        android:layout_width="0dp"
        android:layout_height="0dp"
        android:text="2"
        android:layout_columnWeight="1"
        android:layout_rowWeight="1"
        android:textSize="25sp"
        android:id="@+id/bt2"/>
    <Button
        android:layout_width="0dp"
        android:layout_height="0dp"
        android:text="3"
        android:layout_columnWeight="1"
        android:layout_rowWeight="1"
        android:textSize="25sp"
        android:id="@+id/bt3"/>
    <Button
        android:layout_width="0dp"
        android:layout_height="0dp"
        android:text="="
        android:layout_columnWeight="1"
        android:layout_rowSpan="2"
        android:layout_rowWeight="1"
        android:textSize="25sp"
        android:layout_gravity="fill"
        android:id="@+id/bt_deng"/>
    <Button
        android:layout_width="0dp"
        android:layout_height="0dp"
        android:text="0"
        android:layout_columnWeight="1"
        android:layout_columnSpan="2"
        android:layout_rowWeight="1"
        android:textSize="25sp"
        android:id="@+id/bt0"/>
    <Button
        android:layout_width="0dp"
        android:layout_height="0dp"
        android:text="."
        android:layout_columnWeight="1"
        android:layout_rowWeight="1"
        android:textSize="25sp"
        android:id="@+id/bt_dian"/>
</GridLayout>

java类：

package com.hanqi.testapp2;

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

public class PractiseActivity5 extends AppCompatActivity {

    TextView tv_1;
    Button bt9;
    Button bt4;
    Button bt5;
    Button bt6;
    Button bt_jia;
    Button bt_jian;
    Button bt1;
    Button bt2;
    Button bt3;
    Button bt_cheng;
    Button bt0;
    Button bt_dian;
    Button bt_chu;
    Button bt_tui;
    Button bt7;
    Button bt8;
    Button bt_deng;
    Button bt_c;

    //s1存储数据
    double s1 = 0;
    //判断运算
    int s2 = 0;
    //承载连续运算数字
    double s3 = 0;
    //显示结果
    double s4;
    //运算完成后使用结果直接下次运算
    int s5=0;
    //确认小数点输入一次
    int s6=0;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_practise5);
        tv_1 = (TextView)findViewById(R.id.tv_1);
        bt0 = (Button)findViewById(R.id.bt0);
        bt1 = (Button)findViewById(R.id.bt1);
        bt2 = (Button)findViewById(R.id.bt2);
        bt3 = (Button)findViewById(R.id.bt3);
        bt4 = (Button)findViewById(R.id.bt4);
        bt5 = (Button)findViewById(R.id.bt5);
        bt6 = (Button)findViewById(R.id.bt6);
        bt7 = (Button)findViewById(R.id.bt7);
        bt8 = (Button)findViewById(R.id.bt8);
        bt9 = (Button)findViewById(R.id.bt9);
        bt_jia = (Button)findViewById(R.id.bt_jia);
        bt_jian = (Button)findViewById(R.id.bt_jian);
        bt_cheng = (Button)findViewById(R.id.bt_cheng);
        bt_dian = (Button)findViewById(R.id.bt_dian);
        bt_chu = (Button)findViewById(R.id.bt_chu);
        bt_tui = (Button)findViewById(R.id.bt_tui);
        bt_deng = (Button)findViewById(R.id.bt_deng);
        bt_c = (Button)findViewById(R.id.bt_c);
        bt_tui = (Button)findViewById(R.id.bt_tui);

        bt_onClick bt_l = new bt_onClick();
        bt_dian_onClick bt_dian1 = new bt_dian_onClick();
        bt_jia_onClick bt_jia1 = new bt_jia_onClick();
        bt_jian_onClick bt_jian1 = new bt_jian_onClick();
        bt_cheng_onClick bt_cheng1 = new bt_cheng_onClick();
        bt_chu_onClick bt_chu1 = new bt_chu_onClick();
        bt_deng_onClick bt_deng1 = new bt_deng_onClick();
        bt_c_onClick bt_c1 = new bt_c_onClick();
        bt_tui_onClick bt_tui1 = new bt_tui_onClick();

        bt0.setOnClickListener(bt_l);
        bt1.setOnClickListener(bt_l);
        bt2.setOnClickListener(bt_l);
        bt3.setOnClickListener(bt_l);
        bt4.setOnClickListener(bt_l);
        bt5.setOnClickListener(bt_l);
        bt6.setOnClickListener(bt_l);
        bt7.setOnClickListener(bt_l);
        bt8.setOnClickListener(bt_l);
        bt9.setOnClickListener(bt_l);
        bt_dian.setOnClickListener(bt_dian1);
        bt_jia.setOnClickListener(bt_jia1);
        bt_jian.setOnClickListener(bt_jian1);
        bt_chu.setOnClickListener(bt_chu1);
        bt_cheng.setOnClickListener(bt_cheng1);
        bt_deng.setOnClickListener(bt_deng1);
        bt_c.setOnClickListener(bt_c1);
        bt_tui.setOnClickListener(bt_tui1);
    }
    class bt_onClick implements View.OnClickListener
    {
        @Override
        public void onClick(View v) {
            if (s5 == 1) {
                tv_1.setText(null);
                s1 = 0;
                s2 = 0;
                s3 = 0;
                s4 = 0;
                s5 = 0;
            }
            String str = tv_1.getText().toString();
            //转成按钮
            Button bt = (Button)v;
            //取得按钮上的文字
            String str2 = bt.getText().toString();
            str += str2;
            tv_1.setText(str);
        }
    }
    class bt_dian_onClick implements View.OnClickListener {
        public void onClick(View v) {
            if(s5==1)
            {
                tv_1.setText(null);
                s1=0;
                s2=0;
                s3=0;
                s4=0;
                s5=0;
            }

            if(s6==1)
            {
                return;
            }
            Button bt = (Button) v;
            String str = tv_1.getText().toString();

            if(str.length()==0||str.equals("0.")){
                tv_1.setText("0.");
                return;
            }

            String str2 = bt.getText().toString();
            str += str2;
            tv_1.setText(str);
            s6=1;
        }
    }
    class bt_jia_onClick implements View.OnClickListener
    {
        @Override
        public void onClick(View v) {
            s5 = 0;
            String str=tv_1.getText().toString();
            if (str.length()==0)
            {
                return;
            }
            if (s1 == 0) {
                s1 = Double.parseDouble(str);

            } else {
                s3 = Double.parseDouble(str);
                if (s2 == 0)
                {
                    s1 = s3;
                }
                if (s2 == 1)
                {
                    s1 += s3;
                }
                if (s2 == 2)
                {
                    s1 -= s3;
                }
                if (s2 == 3)
                {
                    s1 *= s3;
                }
                if (s2==4&&s3!=0)
                {
                    s1 /= s3;
                }
                if (s2==4&&s3==0)
                {
                    s1=0;
                    s2=0;
                    s3=0;
                    s4=0;
                    s5=0;
                }
            }
            tv_1.setText(null);
            s2 = 1;
            s6=0;
        }
    }
    class bt_jian_onClick implements View.OnClickListener
    {
        @Override
        public void onClick(View v) {
            s5 = 0;
            String str=tv_1.getText().toString();
            if (str.length()==0)
            {
                return;
            }
            if (s1 == 0) {
                s1 = Double.parseDouble(str);

            } else {
                s3 = Double.parseDouble(str);
                if (s2 == 0)
                {
                    s1 = s3;
                }
                if (s2 == 1)
                {
                    s1 += s3;
                }
                if (s2 == 2)
                {
                    s1 -= s3;
                }
                if (s2 == 3)
                {
                    s1 *= s3;
                }
                if (s2==4&&s3!=0)
                {
                    s1 /= s3;
                }
                if (s2==4&&s3==0)
                {
                    s1=0;
                    s2=0;
                    s3=0;
                    s4=0;
                    s5=0;
                }
            }
            tv_1.setText(null);
            s2 = 2;
            s6=0;
        }
    }
    class bt_cheng_onClick implements View.OnClickListener
    {
        @Override
        public void onClick(View v) {
            s5 = 0;
            String str=tv_1.getText().toString();
            if (str.length()==0)
            {
                return;
            }
            if (s1 == 0) {
                s1 = Double.parseDouble(str);

            } else {
                s3 = Double.parseDouble(str);
                if (s2 == 0)
                {
                    s1 = s3;
                }
                if (s2 == 1)
                {
                    s1 += s3;
                }
                if (s2 == 2)
                {
                    s1 -= s3;
                }
                if (s2 == 3)
                {
                    s1 *= s3;
                }
                if (s2==4&&s3!=0)
                {
                    s1 /= s3;
                }
                if (s2==4&&s3==0)
                {
                    s1=0;
                    s2=0;
                    s3=0;
                    s4=0;
                    s5=0;
                }
            }
            tv_1.setText(null);
            s2 = 3;
            s6=0;
        }
    }
    class bt_chu_onClick implements View.OnClickListener
    {
        @Override
        public void onClick(View v) {
            s5 = 0;
            String str=tv_1.getText().toString();
            if (str.length()==0)
            {
                return;
            }
            if (s1 == 0) {
                s1 = Double.parseDouble(str);

            } else {
                s3 = Double.parseDouble(str);
                if (s2 == 0)
                {
                    s1 = s3;
                }
                if (s2 == 1)
                {
                    s1 += s3;
                }
                if (s2 == 2)
                {
                    s1 -= s3;
                }
                if (s2 == 3)
                {
                    s1 *= s3;
                }
                if (s2==4&&s3!=0)
                {
                    s1 /= s3;
                }
                if (s2==4&&s3==0)
                {
                    s1=0;
                    s2=0;
                    s3=0;
                    s4=0;
                    s5=0;
                }
            }
            tv_1.setText(null);
            s2 = 4;
            s6=0;
        }
    }
    class bt_deng_onClick implements View.OnClickListener {
        public void onClick(View v) {
            String str = tv_1.getText().toString();
            if(str.length()==0)
            {
                return;
            }
            s3 = Double.parseDouble(str);
            if(s3==0&&s2==4)
            {
                return;
            }
            if(s2==0)
            {
                s4=s3;
            }
            if(s2==1)
            {
                s4=s1+s3;
            }
            if(s2==2)
            {
                s4=s1-s3;
            }
            if(s2==3)
            {
                s4=s1*s3;
            }
            if(s2==4&&s3!=0)
            {
                s4=s1/s3;
            }
            if (s2==4&&s3==0)
            {
                s1=0;
                s2=0;
                s3=0;
                s4=0;
                s5=0;
            }
            String str2=s4+"";
            tv_1.setText(str2);
            s5=1;
            s2=0;
            s6=0;
        }
    }
    class bt_c_onClick implements View.OnClickListener {
        public void onClick(View v) {
            s1=0;
            s2=0;
            s3=0;
            s5=0;
            s4=0;
            s6=0;
            tv_1.setText(null);
        }
    }
    class bt_tui_onClick implements View.OnClickListener {
        public void onClick(View v) {

            String str = tv_1.getText().toString();
            if (str.length() == 0) {
                return;
            }
            String str2 = str.substring(0, str.length() - 1);
            tv_1.setText(str2);
            if (s5 == 1) {
                s5 = 0;
            }
        }
    }
}

可实现计算器的基本运算功能

感谢@storm47给予我的帮助