# 实验二

**Repository Path**: ting968/shiyan2

## Basic Information

- **Project Name**: 实验二
- **Description**: Android的计算器包括加减乘除功能，发送广播和接收广播，数据存入数据库
- **Primary Language**: Android
- **License**: Not specified
- **Default Branch**: master
- **Homepage**: None
- **GVP Project**: No

## Statistics

- **Stars**: 0
- **Forks**: 0
- **Created**: 2022-11-13
- **Last Updated**: 2023-06-02

## Categories & Tags

**Categories**: Uncategorized

**Tags**: None

## README

# 实验二
计算器activity：<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:orientation="vertical"
    tools:context=".MainActivity"
    android:background="#000000" >


    <EditText
        android:id="@+id/et_input"
        android:layout_width="match_parent"
        android:layout_height="80dp"
        android:background="@drawable/white"
        android:editable="false"
        android:paddingBottom="5dp"
        android:textSize="30sp" />

    <LinearLayout
        android:layout_width="fill_parent"
        android:layout_height="wrap_content"
        android:layout_marginTop="30dp"
        android:orientation="horizontal"
        android:gravity="center_horizontal">

        <Button
            android:id="@+id/btn_clr"
            android:layout_width="80dp"
            android:layout_height="80dp"
            android:text="C"
            android:textSize="30sp"
            android:paddingRight="15sp"
            android:paddingBottom="15sp"
            android:background="@drawable/selector"/>

        <Button
            android:id="@+id/btn_del"
            android:layout_width="80dp"
            android:layout_height="80dp"
            android:text="⬅"
            android:textSize="30sp"
            android:layout_marginLeft="10dp"
            android:paddingRight="15sp"
            android:paddingBottom="15sp"
            android:background="@drawable/selector"/>

        <Button
            android:id="@+id/btn_div"
            android:layout_width="80dp"
            android:layout_height="80dp"
            android:text="÷"
            android:textSize="30sp"
            android:layout_marginLeft="10dp"
            android:paddingRight="15sp"
            android:paddingBottom="15sp"
            android:background="@drawable/selector"/>

        <Button
            android:id="@+id/btn_mul"
            android:layout_width="80dp"
            android:layout_height="80dp"
            android:text="×"
            android:textSize="30sp"
            android:layout_marginLeft="10dp"
            android:paddingRight="15sp"
            android:paddingBottom="15sp"
            android:background="@drawable/selector"/>
    </LinearLayout>
    <LinearLayout
        android:layout_width="fill_parent"
        android:layout_height="wrap_content"
        android:layout_marginTop="10dp"
        android:orientation="horizontal"
        android:gravity="center_horizontal"
        >
        <Button
            android:id="@+id/btn_7"
            android:layout_width="80dp"
            android:layout_height="80dp"
            android:text="7"
            android:textSize="30sp"
            android:paddingRight="15sp"
            android:paddingBottom="15sp"
            android:background="@drawable/selector"/>
        <Button
            android:id="@+id/btn_8"
            android:layout_width="80dp"
            android:layout_height="80dp"
            android:text="8"
            android:textSize="30sp"
            android:layout_marginLeft="10dp"
            android:paddingRight="15sp"
            android:paddingBottom="15sp"
            android:background="@drawable/selector"/>
        <Button
            android:id="@+id/btn_9"
            android:layout_width="80dp"
            android:layout_height="80dp"
            android:text="9"
            android:textSize="30sp"
            android:layout_marginLeft="10dp"
            android:paddingRight="15sp"
            android:paddingBottom="15sp"
            android:background="@drawable/selector"/>
        <Button
            android:id="@+id/btn_sub"
            android:layout_width="80dp"
            android:layout_height="80dp"
            android:text="-"
            android:textSize="30sp"
            android:layout_marginLeft="10dp"
            android:paddingRight="15sp"
            android:paddingBottom="15sp"
            android:background="@drawable/selector" />
    </LinearLayout>
    <LinearLayout
        android:layout_width="fill_parent"
        android:layout_height="wrap_content"
        android:layout_marginTop="10dp"
        android:orientation="horizontal"
        android:gravity="center_horizontal"
        >
        <Button
            android:id="@+id/btn_4"
            android:layout_width="80dp"
            android:layout_height="80dp"
            android:text="4"
            android:textSize="30sp"
            android:paddingRight="15sp"
            android:paddingBottom="15sp"
            android:background="@drawable/selector"/>
        <Button
            android:id="@+id/btn_5"
            android:layout_width="80dp"
            android:layout_height="80dp"
            android:text="5"
            android:textSize="30sp"
            android:layout_marginLeft="10dp"
            android:paddingRight="15sp"
            android:paddingBottom="15sp"
            android:background="@drawable/selector"/>
        <Button
            android:id="@+id/btn_6"
            android:layout_width="80dp"
            android:layout_height="80dp"
            android:text="6"
            android:textSize="30sp"
            android:layout_marginLeft="10dp"
            android:paddingRight="15sp"
            android:paddingBottom="15sp"
            android:background="@drawable/selector"/>
        <Button
            android:id="@+id/btn_add"
            android:layout_width="80dp"
            android:layout_height="80dp"
            android:text="+"
            android:textSize="30sp"
            android:layout_marginLeft="10dp"
            android:paddingRight="15sp"
            android:paddingBottom="15sp"
            android:background="@drawable/selector"/>
    </LinearLayout>
    <LinearLayout
        android:layout_width="fill_parent"
        android:layout_height="wrap_content"
        android:orientation="horizontal"
        android:layout_marginTop="10dp"
        android:gravity="center_horizontal">
        <LinearLayout
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:orientation="vertical"
            >
            <LinearLayout
                android:layout_width="wrap_content"
                android:layout_height="wrap_content"
                android:orientation="horizontal"
                >
                <Button
                    android:layout_width="80dp"
                    android:layout_height="80dp"
                    android:id="@+id/btn_1"
                    android:text="1"
                    android:textSize="30sp"
                    android:paddingRight="15sp"
                    android:paddingBottom="15sp"
                    android:background="@drawable/selector" />
                <Button
                    android:layout_width="80dp"
                    android:layout_height="80dp"
                    android:id="@+id/btn_2"
                    android:text="2"
                    android:textSize="30sp"
                    android:layout_marginLeft="10dp"
                    android:paddingRight="15sp"
                    android:paddingBottom="15sp"
                    android:background="@drawable/selector" />
                <Button
                    android:layout_width="80dp"
                    android:layout_height="80dp"
                    android:id="@+id/btn_3"
                    android:text="3"
                    android:textSize="30sp"
                    android:layout_marginLeft="10dp"
                    android:paddingRight="15sp"
                    android:paddingBottom="15sp"
                    android:background="@drawable/selector" />
            </LinearLayout>
            <LinearLayout
                android:layout_width="wrap_content"
                android:layout_height="wrap_content"
                android:orientation="horizontal"
                android:layout_marginTop="10dp">
                <Button
                    android:layout_width="170dp"
                    android:layout_height="80dp"
                    android:id="@+id/btn_0"
                    android:text="0"
                    android:textSize="30sp"
                    android:paddingRight="15sp"
                    android:paddingBottom="15sp"
                    android:background="@drawable/selector"/>
                <Button
                    android:layout_width="80dp"
                    android:layout_height="80dp"
                    android:id="@+id/btn_pt"
                    android:text="."
                    android:textSize="30sp"
                    android:layout_marginLeft="10dp"
                    android:paddingRight="15sp"
                    android:paddingBottom="15sp"
                    android:background="@drawable/selector"/>
            </LinearLayout>

        </LinearLayout>

        <Button
            android:id="@+id/btn_eq"
            android:layout_width="80dp"
            android:layout_height="170dp"
            android:layout_marginLeft="10dp"
            android:text="="
            android:textSize="30sp"
            android:paddingRight="15sp"
            android:paddingBottom="15sp"
            android:background="@drawable/button_bg"/>

    </LinearLayout>

</LinearLayout>
mainactivity代码：package com.example.demo;
import android.os.Bundle;
import android.view.View;
import android.widget.Button;
import android.widget.EditText;
import android.content.Intent;
import androidx.appcompat.app.AppCompatActivity;
import android.os.Bundle;
import androidx.appcompat.app.AppCompatActivity;

import com.example.demo.R;

public class MainActivity extends AppCompatActivity implements View.OnClickListener {

    //创建Button对象   也就是activity_main.xml里所设置的ID
    Button btn_0, btn_1, btn_2, btn_3, btn_4, btn_5, btn_6, btn_7, btn_8, btn_9, btn_pt;
    Button btn_mul, btn_div, btn_add, btn_sub;
    Button btn_clr, btn_del, btn_eq;
    EditText et_input;
    boolean clr_flag;    //判断et编辑文本框中是否清空

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        //实例化对象
        setContentView(R.layout.activity_main);
        btn_0 = (Button) findViewById(R.id.btn_0);
        btn_1 = (Button) findViewById(R.id.btn_1);
        btn_2 = (Button) findViewById(R.id.btn_2);
        btn_3 = (Button) findViewById(R.id.btn_3);
        btn_4 = (Button) findViewById(R.id.btn_4);
        btn_5 = (Button) findViewById(R.id.btn_5);
        btn_6 = (Button) findViewById(R.id.btn_6);
        btn_7 = (Button) findViewById(R.id.btn_7);
        btn_8 = (Button) findViewById(R.id.btn_8);
        btn_9 = (Button) findViewById(R.id.btn_9);
        btn_pt = (Button) findViewById(R.id.btn_pt);
        btn_add = (Button) findViewById(R.id.btn_add);
        btn_sub = (Button) findViewById(R.id.btn_sub);
        btn_mul = (Button) findViewById(R.id.btn_mul);
        btn_div = (Button) findViewById(R.id.btn_div);
        btn_clr = (Button) findViewById(R.id.btn_clr);
        btn_del = (Button) findViewById(R.id.btn_del);
        btn_eq = (Button) findViewById(R.id.btn_eq);
        et_input = (EditText) findViewById(R.id.et_input);

        //给按钮设置的点击事件
        btn_0.setOnClickListener(this);
        btn_1.setOnClickListener(this);
        btn_2.setOnClickListener(this);
        btn_3.setOnClickListener(this);
        btn_4.setOnClickListener(this);
        btn_5.setOnClickListener(this);
        btn_6.setOnClickListener(this);
        btn_7.setOnClickListener(this);
        btn_8.setOnClickListener(this);
        btn_9.setOnClickListener(this);
        btn_pt.setOnClickListener(this);
        btn_add.setOnClickListener(this);
        btn_sub.setOnClickListener(this);
        btn_mul.setOnClickListener(this);
        btn_div.setOnClickListener(this);
        btn_clr.setOnClickListener(this);
        btn_del.setOnClickListener(this);
        btn_eq.setOnClickListener(this);
    }

    @Override
    public void onClick(View v) {
        String str = et_input.getText().toString();
        switch (v.getId()) {
            case R.id.btn_0:
            case R.id.btn_1:
            case R.id.btn_2:
            case R.id.btn_3:
            case R.id.btn_4:
            case R.id.btn_5:
            case R.id.btn_6:
            case R.id.btn_7:
            case R.id.btn_8:
            case R.id.btn_9:
            case R.id.btn_pt:
                if (clr_flag) {
                    clr_flag = false;
                    str = "";
                    et_input.setText("");
                }
                et_input.setText(str + ((Button) v).getText());
                break;
            case R.id.btn_add:
            case R.id.btn_sub:
            case R.id.btn_mul:
            case R.id.btn_div:
                if (clr_flag) {
                    clr_flag = false;
                    str = "";
                    et_input.setText("");
                }
                if (str.contains("+") || str.contains("-") || str.contains("×") || str.contains("÷")) {
                    str = str.substring(0, str.indexOf(" "));
                }
                et_input.setText(str + " " + ((Button) v).getText() + " ");
                break;
            case R.id.btn_clr:
                if (clr_flag)
                    clr_flag = false;
                str = "";
                et_input.setText("");
                break;
            case R.id.btn_del: //判断是否为空，然后在进行删除
                if (clr_flag) {
                    clr_flag = false;
                    str = "";
                    et_input.setText("");
                } else if (str != null && !str.equals("")) {
                    et_input.setText(str.substring(0, str.length() - 1));
                }
                break;
            case R.id.btn_eq: //单独运算最后结果
                getResult();//调用下面的方法
                break;
        }
    }

    private void getResult() {
        String exp = et_input.getText().toString();
        if (exp == null || exp.equals("")) return;
        //因为没有运算符所以不用运算
        if (!exp.contains(" ")) {
            return;
        }
        if (clr_flag) {
            clr_flag = false;
            return;
        }
        clr_flag = true;
        //截取运算符前面的字符串
        String s1 = exp.substring(0, exp.indexOf(" "));
        //截取的运算符
        String op = exp.substring(exp.indexOf(" ") + 1, exp.indexOf(" ") + 2);
        //截取运算符后面的字符串
        String s2 = exp.substring(exp.indexOf(" ") + 3);
        double cnt = 0;
        if (!s1.equals("") && !s2.equals("")) {
            double d1 = Double.parseDouble(s1);
            double d2 = Double.parseDouble(s2);
            if (op.equals("+")) {
                cnt = d1 + d2;
            }
            if (op.equals("-")) {
                cnt = d1 - d2;
            }
            if (op.equals("×")) {
                cnt = d1 * d2;
            }
            if (op.equals("÷")) {
                if (d2 == 0) cnt = 0;
                else cnt = d1 / d2;
            }
            if (!s1.contains(".") && !s2.contains(".") && !op.equals("÷")) {
                int res = (int) cnt;
                et_input.setText(res + "");
            } else {
                et_input.setText(cnt + "");
            }
        }
        //如果s1是空    s2不是空  就执行下一步
        else if (!s1.equals("") && s2.equals("")) {
            double d1 = Double.parseDouble(s1);
            if (op.equals("+")) {
                cnt = d1;
            }
            if (op.equals("-")) {
                cnt = d1;
            }
            if (op.equals("×")) {
                cnt = 0;
            }
            if (op.equals("÷")) {
                cnt = 0;
            }
            if (!s1.contains(".")) {
                int res = (int) cnt;
                et_input.setText(res + "");
            } else {
                et_input.setText(cnt + "");
            }
        }
        //如果s1是空    s2不是空  就执行下一步
        else if (s1.equals("") && !s2.equals("")) {
            double d2 = Double.parseDouble(s2);
            if (op.equals("+")) {
                cnt = d2;
            }
            if (op.equals("-")) {
                cnt = 0 - d2;
            }
            if (op.equals("×")) {
                cnt = 0;
            }
            if (op.equals("÷")) {
                cnt = 0;
            }
            if (!s2.contains(".")) {
                int res = (int) cnt;
                et_input.setText(res + "");
            } else {
                et_input.setText(cnt + "");
            }
        } else {
            et_input.setText("");
        }
    }

    public void broadcastIntent(View view) {
        Intent intent = new Intent();
        intent.setAction("com.example.action.DEMO.cnt");
        sendBroadcast(intent);
    }

}

white代码：
<?xml version="1.0" encoding="utf-8"?>
<shape xmlns:android="http://schemas.android.com/apk/res/android" >
    <corners
        android:radius="5dp"/>
    <solid
        android:color="#ffffffff"/>
</shape>

selector代码：
<?xml version="1.0" encoding="utf-8"?>
<selector xmlns:android="http://schemas.android.com/apk/res/android" >
    <item android:drawable="@drawable/gray"
        android:state_pressed="true"/>
    <item android:drawable="@drawable/white"/>
</selector>
gray代码：
<?xml version="1.0" encoding="utf-8"?>
<shape xmlns:android="http://schemas.android.com/apk/res/android" >
    <corners
        android:radius="5dp"/>
    <solid
        android:color="#ffDEDEDE"/>
</shape>
第二个activity：
activity：
<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout 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" tools:context=".MainActivity">

    <TextView
        android:id="@+id/textView1"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="计算结果"
        android:layout_alignParentTop="true"
        android:layout_centerHorizontal="true"
        android:textSize="30dp" />

    <ImageButton
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:id="@+id/imageButton"
        android:src="@drawable/ic_launcher"
        android:layout_centerVertical="true"
        android:layout_centerHorizontal="true" />

    <Button
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:id="@+id/button"
        android:text="接收"
        android:onClick="broadcastIntent"
        android:layout_below="@+id/imageButton"
        android:layout_alignEnd="@+id/imageButton"
        android:layout_alignStart="@+id/imageButton" />
</RelativeLayout>
mainactivity代码：
package com.example.broadcastcustom;

import android.content.Intent;
import androidx.appcompat.app.AppCompatActivity;
import android.os.Bundle;
import android.view.View;

public class MainActivity extends AppCompatActivity {

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

    public void broadcastIntent (View view) {
        Intent intent = new Intent();
        intent.setAction("com.example.action.DEMO_BROADCAST");
        intent.setPackage("com.example.broadcastcustom");
        sendBroadcast(intent);
    }
}
Androidmainfest代码：
<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
    package="com.example.broadcastcustom">

    <application
        android:allowBackup="true"
        android:icon="@mipmap/ic_launcher"
        android:label="@string/app_name"
        android:roundIcon="@mipmap/ic_launcher_round"
        android:supportsRtl="true"
        android:theme="@style/Theme.Broadcastcustom">
        <activity android:name=".MainActivity"
            android:exported="true">
            <intent-filter>
                <action android:name="android.intent.action.MAIN" />

                <category android:name="android.intent.category.LAUNCHER" />
            </intent-filter>
        </activity>

        <receiver
            android:name=".MyReceiver"
            android:enabled="true"
            android:exported="true">
            <intent-filter android:priority="20" >
                <action android:name="com.example.action.DEMO_BROADCAST" >
                </action>
            </intent-filter>
        </receiver>
    </application>

</manifest>
myreceiver代码：
package com.example.broadcastcustom;

import android.content.BroadcastReceiver;
import android.content.Context;
import android.content.Intent;
import android.widget.Toast;

public class MyReceiver extends BroadcastReceiver {

    @Override
    public void onReceive(Context context, Intent intent) {
        // TODO: This method is called when the BroadcastReceiver is receiving
        // an Intent broadcast.
        //throw new UnsupportedOperationException("Not yet implemented");
        Toast.makeText(context,"6",Toast.LENGTH_LONG).show();
    }
}
第三个activity：
public class OrderDBHelper extends SQLiteOpenHelper{
    private static final int DB_VERSION = 1;
    private static final String DB_NAME = "myTest.db";
    public static final String TABLE_NAME = "Orders";

    public OrderDBHelper(Context context) {
        super(context, DB_NAME, null, DB_VERSION);
    }

    @Override
    public void onCreate(SQLiteDatabase sqLiteDatabase) {
        // create table Orders(Id integer primary key, CustomName text, OrderPrice integer, Country text);
        String sql = "create table if not exists " + TABLE_NAME + " (Id integer primary key, CustomName text, OrderPrice integer, Country text)";
        sqLiteDatabase.execSQL(sql);
    }

    @Override
    public void onUpgrade(SQLiteDatabase sqLiteDatabase, int oldVersion, int newVersion) {
        String sql = "DROP TABLE IF EXISTS " + TABLE_NAME;
        sqLiteDatabase.execSQL(sql);
        onCreate(sqLiteDatabase);
    }
    public OrderDao(Context context) {
        this.context = context;
        ordersDBHelper = new OrderDBHelper(context);
}

}