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

package com.example.myapplication;

import androidx.appcompat.app.AppCompatActivity;
import android.net.Uri;
import android.os.Bundle;
import android.util.Log;
import android.content.Intent;
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 click1(View view){
        Intent intent=new Intent(this,oneActivity.class);
        startActivity(intent);

    }

    public void click2(View view){
        Intent intent=new Intent();
        intent.setAction("cn.it.ab_cd");
        intent.addCategory("android.intent.category.DEFAULT");
        startActivity(intent);
    }
}

<?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:orientation="vertical">

    <Button
        android:id="@+id/v1"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:onClick="click1"
        android:text="按钮1开启界面2"
        android:textColor="#FFC0CB"
        android:textSize="30sp" />

    <Button
        android:id="@+id/v2"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:onClick="click2"
        android:text="按钮2开启界面3"
        android:textSize="30sp"
        android:textColor="#DDA0DD" />

</LinearLayout>

package com.example.myapplication;

import androidx.appcompat.app.AppCompatActivity;

import android.os.Bundle;

public class oneActivity extends AppCompatActivity {

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

<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout 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=".oneActivity">
    <TextView
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="界面2"
        android:textSize="40dp"
        android:textColor="#87CEFA"
        android:layout_centerVertical="true"
        android:layout_centerHorizontal="true"
        />
</RelativeLayout>

package com.example.myapplication;

import androidx.appcompat.app.AppCompatActivity;

import android.os.Bundle;

public class twoActivity extends AppCompatActivity {

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

<?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=".twoActivity">
            <intent-filter>
                <action android:name="cn.it.ab_cd"/>
                <category android:name="android.intent.category.DEFAULT"/>
            </intent-filter>
        </activity>
        <activity android:name=".oneActivity" />
        <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>

<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout 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=".twoActivity">

    <TextView
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="界面3"
        android:textSize="40dp"
        android:textColor="#9370DB"
        android:layout_centerVertical="true"
        android:layout_centerHorizontal="true"
        />
</RelativeLayout>

2.在界面1做一个按钮开启浏览器访问百度

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 {

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
    }
    public void click1(View view){
        Intent intent=new Intent();
        intent.setAction("android.intent.action.VIEW");
        intent.setData(Uri.parse("http://www.baidu.com"));
        startActivity(intent);
    }
}

<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:padding="8dp"
>
    <Button
        android:id="@+id/b1"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:textColor="#FFC0CB"
        android:text="按钮1"
        android:textSize="40sp"
        android:layout_centerVertical="true"
        android:layout_centerHorizontal="true"
        android:onClick="click1"/>

</RelativeLayout>

3.2个edittext,4个按钮一个textview，实现简单计算器。

提示1：如何获取edittext上的数据？
String num1=((EditText)(findViewById(R.id.et1))).getText().toString();//获取et1上面的文本，并
转成字符串
提示2：字符串如何转int
int n1=Integer.parseInt(num1);
提示3:如何把计算结果显示在textview上？
TextView tv1=(TextView)findViewById(R.id.tv1);//获取控件
tv1.setText("1233213");//用settext方法赋值

package com.example.myapplication;

import androidx.appcompat.app.AppCompatActivity;

import android.view.View;
import android.widget.EditText;
import android.os.Bundle;
import android.widget.TextView;

public class MainActivity extends AppCompatActivity {

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        findViewById(R.id.c1).setOnClickListener(new View.OnClickListener(){

            @Override
            public void onClick(View view) {
                String num1=((EditText)(findViewById(R.id.b1))).getText().toString();
                String num2=((EditText)(findViewById(R.id.b2))).getText().toString();
                int a1= Integer.parseInt( num1 );
                int a2=Integer.parseInt( num2 );
                int a3=a1+a2;
                TextView d1=findViewById( R.id.d1 );
                d1.setText( "="+a3);
            }
        });

        findViewById(R.id.c2).setOnClickListener(new View.OnClickListener(){

            @Override
            public void onClick(View view) {
                String num1=((EditText)(findViewById(R.id.b1))).getText().toString();
                String num2=((EditText)(findViewById(R.id.b2))).getText().toString();
                int a1= Integer.parseInt( num1 );
                int a2=Integer.parseInt( num2 );
                int a3=a1-a2;
                TextView d1=findViewById( R.id.d1 );
                d1.setText( "="+a3 );
            }
        });

        findViewById(R.id.c3).setOnClickListener(new View.OnClickListener(){

            @Override
            public void onClick(View view) {
                String num1=((EditText)(findViewById(R.id.b1))).getText().toString();
                String num2=((EditText)(findViewById(R.id.b2))).getText().toString();
                int a1= Integer.parseInt( num1 );
                int a2=Integer.parseInt( num2 );
                int a3=a1*a2;
                TextView d1=findViewById( R.id.d1 );
                d1.setText( "="+a3 );
            }
        });

        findViewById(R.id.c4).setOnClickListener(new View.OnClickListener(){

            @Override
            public void onClick(View view) {
                String num1=((EditText)(findViewById(R.id.b1))).getText().toString();
                String num2=((EditText)(findViewById(R.id.b2))).getText().toString();
                int a1= Integer.parseInt( num1 );
                int a2=Integer.parseInt( num2 );
                int a3=a1/a2;
                TextView d1=findViewById( R.id.d1 );
                d1.setText( "="+a3 );
            }
        });
    }

}

<?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=".MainActivity"
    android:orientation="vertical"
    android:background="#ADD8E6">

    <TextView
        android:id="@+id/a1"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="计算器"
        android:textSize="30sp"
        android:textColor="#FFB6C1"/>

    <EditText
        android:id="@+id/b1"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:hint="请输入数字"
    />

    <EditText
        android:id="@+id/b2"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:hint="请输入数字"/>

    <Button
        android:id="@+id/c1"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:text="+"
        android:textSize="30sp"
        android:background="#D8BFD8"
        />

    <Button
        android:id="@+id/c2"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:text="-"
        android:textSize="30sp"
        android:background="#D8BFD8"
        />

    <Button
        android:id="@+id/c3"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:text="*"
        android:textSize="30sp"
        android:background="#D8BFD8"
        />

    <Button
        android:id="@+id/c4"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:text="/"
        android:textSize="30sp"
        android:background="#D8BFD8"
        />

    <TextView
        android:id="@+id/d1"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="="
        android:textSize="30dp"/>
</LinearLayout>