计算器

layout代码：

<?xml version="1.0" encoding="utf-8"?>
<GridLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:paddingBottom="@dimen/activity_vertical_margin"
    android:paddingLeft="@dimen/activity_horizontal_margin"
    android:paddingRight="@dimen/activity_horizontal_margin"
    android:paddingTop="@dimen/activity_vertical_margin"
    tools:context="com.example.wang.jisuanji.MainActivity"
    android:rowCount="6"
    android:columnCount="4">

    <TextView
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:background="#ccc"
        android:layout_columnSpan="4"
        android:layout_rowWeight="1"
        android:textSize="40sp"
        android:gravity="right|center_vertical"
        android:id="@+id/input"/>
    <TextView
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:background="#ccc"
        android:layout_columnSpan="4"
        android:layout_rowWeight="1"
        android:textSize="40sp"
        android:gravity="right|center_vertical"
        android:id="@+id/output"/>
    <Button
        android:layout_width="0dp"
        android:layout_height="0dp"
        android:text="C"
        android:textSize="25sp"
        android:id="@+id/bt_C"
        android:layout_columnWeight="1"
        android:layout_rowWeight="1"/>
    <Button
        android:layout_width="0dp"
        android:layout_height="0dp"
        android:text="DEL"
        android:textSize="25sp"
        android:id="@+id/bt_DEL"
        android:layout_columnWeight="1"
        android:layout_rowWeight="1"/>
    <Button
        android:layout_width="0dp"
        android:layout_height="0dp"
        android:text="÷"
        android:textSize="25sp"
        android:id="@+id/bt_chu"
        android:layout_columnWeight="1"
        android:layout_rowWeight="1"/>
    <Button
        android:layout_width="0dp"
        android:layout_height="0dp"
        android:text="×"
        android:textSize="25sp"
        android:id="@+id/bt_cheng"
        android:layout_columnWeight="1"
        android:layout_rowWeight="1"/>
    <Button
        android:layout_width="0dp"
        android:layout_height="0dp"
        android:text="7"
        android:textSize="25sp"
        android:id="@+id/bt_7"
        android:layout_columnWeight="1"
        android:layout_rowWeight="1"/>
    <Button
        android:layout_width="0dp"
        android:layout_height="0dp"
        android:text="8"
        android:textSize="25sp"
        android:id="@+id/bt_8"
        android:layout_columnWeight="1"
        android:layout_rowWeight="1"/>
    <Button
        android:layout_width="0dp"
        android:layout_height="0dp"
        android:text="9"
        android:textSize="25sp"
        android:id="@+id/bt_9"
        android:layout_columnWeight="1"
        android:layout_rowWeight="1"/>
    <Button
        android:layout_width="0dp"
        android:layout_height="0dp"
        android:text="-"
        android:textSize="25sp"
        android:id="@+id/bt_jian"
        android:layout_columnWeight="1"
        android:layout_rowWeight="1"/>
    <Button
        android:layout_width="0dp"
        android:layout_height="0dp"
        android:text="4"
        android:textSize="25sp"
        android:id="@+id/bt_4"
        android:layout_columnWeight="1"
        android:layout_rowWeight="1"/>
    <Button
        android:layout_width="0dp"
        android:layout_height="0dp"
        android:text="5"
        android:textSize="25sp"
        android:id="@+id/bt_5"
        android:layout_columnWeight="1"
        android:layout_rowWeight="1"/>
    <Button
        android:layout_width="0dp"
        android:layout_height="0dp"
        android:text="6"
        android:textSize="25sp"
        android:id="@+id/bt_6"
        android:layout_columnWeight="1"
        android:layout_rowWeight="1"/>
    <Button
        android:layout_width="0dp"
        android:layout_height="0dp"
        android:text="+"
        android:onClick="jia_OnClick"
        android:textSize="25sp"
        android:id="@+id/bt_jia"
        android:layout_columnWeight="1"
        android:layout_rowWeight="1"/>
    <Button
        android:layout_width="0dp"
        android:layout_height="0dp"
        android:text="1"
        android:textSize="25sp"
        android:id="@+id/bt_1"
        android:layout_columnWeight="1"
        android:layout_rowWeight="1"/>
    <Button
        android:layout_width="0dp"
        android:layout_height="0dp"
        android:text="2"
        android:textSize="25sp"
        android:id="@+id/bt_2"
        android:layout_columnWeight="1"
        android:layout_rowWeight="1"/>
    <Button
        android:layout_width="0dp"
        android:layout_height="0dp"
        android:text="3"
        android:textSize="25sp"
        android:id="@+id/bt_3"
        android:layout_columnWeight="1"
        android:layout_rowWeight="1"/>
    <Button
        android:layout_width="0dp"
        android:layout_height="0dp"
        android:text="="
        android:textSize="25sp"
        android:id="@+id/bt_deng"
        android:onClick="deng_OnClick"
        android:layout_rowSpan="2"
        android:layout_columnWeight="1"
        android:layout_rowWeight="1"/>
    <Button
        android:layout_width="0dp"
        android:layout_height="0dp"
        android:text="0"
        android:textSize="25sp"
        android:layout_columnSpan="2"
        android:id="@+id/bt_0"
        android:layout_columnWeight="1"
        android:layout_rowWeight="1"/>

    <Button
        android:layout_width="0dp"
        android:layout_height="0dp"
        android:text="."
        android:textSize="40sp"
        android:id="@+id/bt_dian"
        android:layout_columnWeight="1"
        android:layout_rowWeight="1"/>




</GridLayout>

Activity代码：

package com.example.my.myapplication;

import android.app.Activity;
import android.os.Bundle;
import android.util.Log;
import android.view.View;
import android.widget.Button;
import android.widget.TextView;

public class Testjisuanqei extends Activity {


    //单目运算可以实现连续进行，实现不了运算符之间的运算




    String str = "";
    String str1="";
    String str2="";
    String string="";
    String stringq="";
    String stringh="";

    String[] strings=new String[200];

    String[] strings1=new String[200];

    TextView input;
    TextView output;
    Button bt_0;
    Button bt_1;
    Button bt_2;
    Button bt_3;
    Button bt_4;
    Button bt_5;
    Button bt_6;
    Button bt_7;
    Button bt_8;
    Button bt_9;
    Button bt_jia;
    Button bt_jian;
    Button bt_cheng;
    Button bt_chu;
    Button bt_DEL;
    Button bt_C;
    Button bt_dian;
    Button bt_deng;
    int i, j;
    int g =0;
    int k=0;
    double a = 0;
    double b = 0;
    double c=0 ;

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

        input = (TextView) findViewById(R.id.input);
        output = (TextView) findViewById(R.id.output);
        bt_0 = (Button) findViewById(R.id.bt_0);
        bt_1 = (Button) findViewById(R.id.bt_1);
        bt_2 = (Button) findViewById(R.id.bt_2);
        bt_3 = (Button) findViewById(R.id.bt_3);
        bt_4 = (Button) findViewById(R.id.bt_4);
        bt_5 = (Button) findViewById(R.id.bt_5);
        bt_6 = (Button) findViewById(R.id.bt_6);
        bt_7 = (Button) findViewById(R.id.bt_7);
        bt_8 = (Button) findViewById(R.id.bt_8);
        bt_9 = (Button) findViewById(R.id.bt_9);
        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_chu = (Button) findViewById(R.id.bt_chu);
        bt_dian = (Button) findViewById(R.id.bt_dian);
        bt_DEL = (Button) findViewById(R.id.bt_DEL);
        bt_C = (Button) findViewById(R.id.bt_C);
        bt_deng = (Button) findViewById(R.id.bt_deng);

        Bt_OnClickListener bt_onClickListener = new Bt_OnClickListener();

        bt_0.setOnClickListener(bt_onClickListener);
        bt_1.setOnClickListener(bt_onClickListener);
        bt_2.setOnClickListener(bt_onClickListener);
        bt_3.setOnClickListener(bt_onClickListener);
        bt_4.setOnClickListener(bt_onClickListener);
        bt_5.setOnClickListener(bt_onClickListener);
        bt_6.setOnClickListener(bt_onClickListener);
        bt_7.setOnClickListener(bt_onClickListener);
        bt_8.setOnClickListener(bt_onClickListener);
        bt_9.setOnClickListener(bt_onClickListener);
        bt_dian.setOnClickListener(bt_onClickListener);
        //bt_jia.setOnClickListener(bt_onClickListener);
        bt_C.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                str = "0";
                input.setText(str);
                str = "";
                output.setText("");
                string="";
                a=0;
                k=g=0;
            }
        });




        bt_jia.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                Button bt = (Button) v;
                str1 = str;//str1放前一个数据
                //   string = str;//存放加号以前的数据
                str = str + bt.getText().toString();

                strings[g]=str;
                Log.e("TAG","strings["+g+"]="+strings[g]);
                g++;

                input.setText(str);

                stringq=string;
                if (i==1)
                {
                    // a = a-Double.parseDouble(stringq);
                    if (a==0)
                    {
                        a =Double.parseDouble(stringq)-a;
                    }
                    else
                    {
                        Log.e("TAG","jianss_a="+a);
                        a =a-Double.parseDouble(stringq);
                    }
                }
                else if (i==2)
                {
                    if (a==0)
                    {
                        a=a+1;
                    }
                    a = Double.parseDouble(stringq)*a;
                }
                else if(i==3)
                {
                    if (a==0)
                    {
                        a=a+1;
                        a = Double.parseDouble(stringq)/a;
                    }
                    else
                    {
                        a =a/Double.parseDouble(stringq);
                    }
                }
                else if (i==3)
                {
                    if (a==0)
                    {
                        a=a+1;
                        a = Double.parseDouble(stringq)/a;
                    }
                    else
                    {
                        a =a/Double.parseDouble(stringq);
                    }
                }

                else
                {
                    a = Double.parseDouble(stringq)+a;
                }
                string="";

                i = jia();//返回一个0
            }
        });

        bt_jian.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                Button bt = (Button) v;
                str1 = str;//str1放前一个数据
                //   string = str;//存放加号以前的数据
                str = str + bt.getText().toString();

                strings[g]=str;
                Log.e("TAG","strings["+g+"]="+strings[g]);
                g++;
                input.setText(str);

                stringq=string;
                if (a==0)
                {
                    a =Double.parseDouble(stringq)-a;
                }
                else if (i==0)
                {
                    Log.e("TAG","jian1_a="+a);
                    a =a+Double.parseDouble(stringq);
                }
                else if (i==2)
                {
                    if (a==0)
                    {
                        a=a+1;
                    }
                    a = Double.parseDouble(stringq)*a;
                }
                else if(i==3)
                {
                    if (a==0)
                    {
                        a=a+1;
                        Log.e("TAG","a==="+a);
                        a = Double.parseDouble(stringq)/a;
                        Log.e("TAG","a===1"+a);
                    }
                    else
                    {
                        Log.e("TAG","a=="+a);
                        a =a/Double.parseDouble(stringq);
                        Log.e("TAG","a==1"+a);
                    }
                }

                else if (i==3)
                {
                    if (a==0)
                    {
                        a=a+1;
                        a = Double.parseDouble(stringq)/a;
                    }
                    else
                    {
                        a =a/Double.parseDouble(stringq);
                    }
                }
                else
                {
                    Log.e("TAG","jian_a="+a);
                    a =a-Double.parseDouble(stringq);
                }
                Log.e("TAG", "jian_a1=" + a);


                i = jian();//返回一个0

                string="";
            }
        });

        bt_cheng.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                Button bt = (Button) v;
                str1 = str;//str1放前一个数据
                //   string = str;//存放加号以前的数据
                str = str + bt.getText().toString();
                strings[g]=str;

                Log.e("TAG","stringscheng["+g+"]="+strings[g]);
                g++;
                input.setText(str);

                stringq=string;

                Log.e("TAG","stringscheng1["+g+"]="+string);
                if (a==0)
                {
                    a=a+1;
                    a=a*Double.parseDouble(stringq);
                }
                else if (i==0)
                {
                    //Log.e("TAG","jianqwe_a="+a);
                    a =a+Double.parseDouble(stringq);
                    //Log.e("TAG","jianqweqq_a="+a);
                }
                else if (i==1)
                {
                    if (a==0)
                    {
                        a =Double.parseDouble(stringq)-a;
                    }
                    else
                    {
                        Log.e("TAG","jian_a="+a);
                        a =a-Double.parseDouble(stringq);

                    }
                }
                else if(i==3)
                {
                    if (a==0)
                    {
                        a=a+1;
                        a = Double.parseDouble(stringq)/a;

                    }
                    else
                    {
                        a =a/Double.parseDouble(stringq);

                        //Log.e("TAG","stringDEL2="+string);
                    }
                }
                else
                {
                    a = Double.parseDouble(stringq)*a;

                }

                string="";
                i = cheng();
            }
        });

        bt_chu.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                Button bt = (Button) v;
                str1 = str;//str1放前一个数据
                //   string = str;//存放加号以前的数据
                str = str + bt.getText().toString();
                strings[g]=str;
                Log.e("TAG","strings["+g+"]="+strings[g]);
                g++;
                input.setText(str);
                stringq=string;
                if (a==0)
                {
                    a=a+1;
                    a = Double.parseDouble(stringq)/a;
                }

                else if (i==0)
                {
                    Log.e("TAG","jian1_a="+a);
                    a =a+Double.parseDouble(stringq);
                }
                else if (i==2)
                {
                    if (a==0)
                    {
                        a=a+1;
                    }
                    a = Double.parseDouble(stringq)*a;
                }
                else if (i==1)
                {
                    if (a==0)
                    {
                        a =Double.parseDouble(stringq)-a;
                    }
                    else
                    {
                        Log.e("TAG","jian_a="+a);
                        a =a-Double.parseDouble(stringq);

                    }
                }

                else
                {
                    a =a/Double.parseDouble(stringq);
                }

                //    string="";
                //    string1 = "";//存放加号以后的数据
                //   //23+23+45=
                string="";
                i = chu();//返回一个0
            }
        });


        bt_deng.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                Button bt = (Button) v;
                str1 = str;//str1放前一个数据
                str = str + bt.getText().toString();
                strings[g]=str;
                Log.e("TAG","strings["+g+"]="+strings[g]);
                g++;
                input.setText(str);
                deng(i);
                str = "" + c;//使下一次输入时显示页面为c

            }
        });

        bt_DEL.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                Log.e("TAG", "stringsDEL[" + g + "]=" + strings[g - 2]);
                input.setText(strings[g - 2]);
                str=strings[g-2];
                g--;
                //string=str2;
                string=strings1[k-1];

                Log.e("TAG","stringDEL="+string);
                k--;
            }
        });


    }


    class Bt_OnClickListener implements View.OnClickListener {
        @Override
        public void onClick(View v) {
            Button bt = (Button) v;
            str1 = str;//str1放前一个数据

            str = str + bt.getText().toString();

            strings[g]=str;
            Log.e("TAG","strings["+g+"]="+strings[g]);
            g++;
            input.setText(str);

//            if (DEL_OnClick(v)==8)
//            {
//                string=str2;
//            }
            str2=string;
            strings1[k]=str2;

            Log.e("TAG", "strings1111[" + k + "]=" + strings1[k]);
            k++;
            string = string + bt.getText().toString();
            //str2=bt.getText().toString();


            output.setText("");
        }
    }

    public int jia() {  return 0; }

    public int jian() { return 1; }

    public int cheng() { return 2; }

    public int chu() {  return 3; }


    //结果
    public void   deng(int i) {

        if (i == 0) {//执行加法

            stringh=string;

            b = Double.parseDouble(stringh);

            c = a+b;
        }
        if (i == 1) {
            stringh=string;

            b = Double.parseDouble(stringh);
            c = a-b;
        }
        if (i == 2) {
            stringh=string;

            b = Double.parseDouble(stringh);

            c = a*b;
        }
        if (i == 3) {

            stringh=string;
            b = Double.parseDouble(stringh);
            c = (double)a/b;
        }
        output.setText("" + c);
    }
}