Android第七周作业

1.三个界面，界面1点击按钮使用显式意图开启界面2.
界面2点击按钮隐式意图开启界面3

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:layout_margin="20dp"
    android:orientation="vertical">

    <Button
        android:id="@+id/interface2"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="显示意图 --> 界面二" />

    <Button
        android:id="@+id/interface3"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="隐式意图 --> 界面三" />
</LinearLayout>

<?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=".Second_Activity">

    <TextView
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_margin="30dp"
        android:text="Second_interface"
        android:textSize="40sp"
        android:textStyle="bold" />

    <Button
        android:id="@+id/interface2_3"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="隐式意图 --> 界面三" />

</LinearLayout>

<?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"
    tools:context=".Third_Activity"
    android:orientation="vertical">

    <TextView
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="Third_interface"
        android:textSize="40sp"
        android:textStyle="bold"
        android:layout_margin="30dp"/>

</LinearLayout>

package com.example.myapplication;

import androidx.appcompat.app.AppCompatActivity;

import android.content.Intent;
import android.os.Bundle;
import android.view.View;


public class MainActivity extends AppCompatActivity implements View.OnClickListener {

    private Object Second_Activity;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        findViewById(R.id.interface2).setOnClickListener(this);
        findViewById(R.id.interface3).setOnClickListener(this);
    }

    @Override
    public void onClick(View view) {
        switch (view.getId()) {
            case R.id.interface2:
                Intent intent1 = new Intent(MainActivity.this,Second_Activity.class);
                startActivity(intent1);
                break;
            case R.id.interface3:
                Intent intent2 = new Intent();
                intent2.setAction("com.example.START_ACTIVITY");
                startActivity(intent2);
                break;
        }

    }
}

package com.example.myapplication;

import androidx.appcompat.app.AppCompatActivity;

import android.content.Intent;
import android.os.Bundle;
import android.view.View;

public class Second_Activity extends AppCompatActivity implements View.OnClickListener {

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_second_);
        findViewById(R.id.interface2_3).setOnClickListener(this);
    }

    @Override
    public void onClick(View view) {
        switch (view.getId()){
            case R.id.interface2_3:
                Intent intent2_3 = new Intent();
                intent2_3.setAction("com.example.START_ACTIVITY");
                startActivity(intent2_3);
                break;

        }
    }
}

<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
    package="com.example.myapplication">

    <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/AppTheme">
        <activity android:name=".Third_Activity">
            <intent-filter>
                <action android:name="com.example.START_ACTIVITY" />

                <category android:name="android.intent.category.DEFAULT" />
            </intent-filter>
        </activity>
        <activity android:name=".Second_Activity" />
        <activity android:name=".MainActivity">
            <intent-filter>
                <action android:name="android.intent.action.MAIN" />

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

</manifest>

 

 2.在界面1做一个按钮开启浏览器访问百度

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:layout_margin="20dp"
    android:orientation="vertical">
    <Button
        android:id="@+id/OpenBrowser"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="OpenBrowser --> baidu.com"/>
</LinearLayout>

package com.example.myapplication;

import androidx.appcompat.app.AppCompatActivity;

import android.content.Intent;
import android.net.Uri;
import android.os.Bundle;
import android.view.View;


public class MainActivity extends AppCompatActivity implements View.OnClickListener {

    private Object Second_Activity;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        findViewById(R.id.interface2).setOnClickListener(this);
        findViewById(R.id.interface3).setOnClickListener(this);
        findViewById(R.id.OpenBrowser).setOnClickListener(this);
    }

    @Override
    public void onClick(View view) {
        switch (view.getId()) {
            case R.id.interface2:
                Intent intent1 = new Intent(MainActivity.this,Second_Activity.class);
                startActivity(intent1);
                break;
            case R.id.interface3:
                Intent intent2 = new Intent();
                intent2.setAction("com.example.START_ACTIVITY");
                startActivity(intent2);
                break;
            case R.id.OpenBrowser:
                Intent intent3 = new Intent();
                // 设置开启系统浏览器动作
                intent3.setAction("android.intent.action.VIEW");
                // 设置要打开的网页
                intent3.setData(Uri.parse("http://baidu.com"));
                startActivity(intent3);
                break;
        }

    }
}

 

 3.2个edittext,4个按钮一个textview，实现简单计算器。

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:layout_margin="20dp"
    android:orientation="vertical">

    <EditText
        android:id="@+id/et1"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:layout_gravity="center"
        android:layout_margin="10dp"
        android:gravity="center"
        android:maxLines="1"
        android:textSize="50sp"
        android:phoneNumber="true"
        android:scrollHorizontally="false" />


    <TextView
        android:id="@+id/tv_1"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:gravity="center"
        android:textColor="#FF0000"
        android:textSize="30sp"
        android:text="运算符"/>

    <EditText
        android:id="@+id/et2"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:layout_gravity="center"
        android:layout_margin="10dp"
        android:gravity="center"
        android:maxLines="1"
        android:textSize="50sp"
        android:phoneNumber="true"
        android:scrollHorizontally="false" />
    <LinearLayout
        android:layout_width="match_parent"
        android:layout_height="wrap_content">

        <Button
            android:id="@+id/sum"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:text="加(+)" />

        <Button
            android:id="@+id/minus"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:text="减(-)" />

        <Button
            android:id="@+id/product"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:text="乘(*)" />

        <Button
            android:id="@+id/divide"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:text="除(/)" />
    </LinearLayout>
    <TextView
        android:id="@+id/tv_2"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:gravity="center"
        android:textSize="60sp"
        android:textColor="#0000FF"
        />

</LinearLayout>

package com.example.myapplication;

import androidx.appcompat.app.AppCompatActivity;

import android.os.Bundle;
import android.view.Gravity;
import android.view.View;
import android.widget.Button;
import android.widget.EditText;
import android.widget.TextView;
import android.widget.Toast;


public class MainActivity extends AppCompatActivity implements View.OnClickListener {

    private Object Second_Activity;
    private EditText et1,et2;
    private TextView tv1,tv2;
    private String textx;
    private float num;
    private Button sum,minus,product,divide;
    private Toast toast;

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

        et1 = (EditText)findViewById(R.id.et1);

        tv1 = findViewById(R.id.tv_1);
        tv2 = findViewById(R.id.tv_2);
        sum = findViewById(R.id.sum);
        sum.setOnClickListener(this);
        minus = findViewById(R.id.minus);
        minus.setOnClickListener(this);
        product = findViewById(R.id.product);
        product.setOnClickListener(this);
        divide = findViewById(R.id.divide);
        divide.setOnClickListener(this);

    }

    @Override
    public void onClick(View view) {
        et2 = (EditText)findViewById(R.id.et2);
        float num1 = Integer.parseInt(et1.getText().toString());
        float num2 = Integer.parseInt(et2.getText().toString());
        switch (view.getId()){
            case R.id.sum:
                num = num1 +num2;
                tv1.setText("加（+）");
                break;
            case R.id.minus:
                num = num1 -num2;
                tv1.setText("减（-）");
                break;
            case R.id.product:
                num = num1 *num2;
                tv1.setText("乘（*）");
                break;
            case R.id.divide:
                num = (float)(num1*1.0 /num2);
                tv1.setText("除（/）");
                if (num2 == 0){
                    Toast.makeText(this,"错误",Toast.LENGTH_LONG).show();
                }
                    break;
        }
        textx = String.valueOf(num);
        tv2.setText(textx);


    }
}