安卓第七周

1.

<?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">

    <Button
        android:id="@+id/bt_1"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:background="#F2B4FC"
        android:text="显示意图开启界面2"
        android:textSize="20sp"
        android:textColor="#000000"
        android:layout_marginTop="20dp"
        android:layout_marginLeft="10dp"/>

</LinearLayout>
<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=".Main2Activity">

    <Button
        android:id="@+id/bt_2"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:background="#EEA6BF"
        android:text="隐式意图开启界面3"
        android:textSize="20sp"
        android:textColor="#000000"
        android:layout_marginLeft="10dp"
        android:layout_marginTop="20dp"/>

</LinearLayout>
<?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"
    android:background="#A5D4FA"
    tools:context=".Main3Activity">

    <TextView
        android:id="@+id/tv_1"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="界面3"
        android:textSize="20sp"
        android:layout_centerInParent="true"
        android:textColor="#000000"/>

</RelativeLayout>
<activity android:name=".Main3Activity">
            <intent-filter>
                <action android:name="com.ym.second" />

                <category android:name="android.intent.category.DEFAULT" />
            </intent-filter>
        </activity>
        <activity android:name=".Main2Activity" >
        </activity>
        <activity android:name=".MainActivity">
            <intent-filter>
                <action android:name="android.intent.action.MAIN" />

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

import androidx.appcompat.app.AppCompatActivity;

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

public class MainActivity extends AppCompatActivity {

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        Button btn1=(Button)findViewById(R.id.bt_1);
        btn1.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View view) {
                Intent intent=new Intent(MainActivity.this,Main2Activity.class);
                startActivity(intent);
            }
        });
    }
}

import androidx.appcompat.app.AppCompatActivity;

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

public class Main2Activity extends AppCompatActivity {

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main2);
        Button btn2=(Button)findViewById(R.id.bt_2);
        btn2.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View view) {
                Intent intent=new Intent();
                intent.setAction("com.ym.second");
                startActivity(intent);
            }
        });
    }
}

 

 

 

import androidx.appcompat.app.AppCompatActivity;
 
import android.content.Intent;
import android.net.Uri;
import android.os.Bundle;
import android.view.View;
import android.widget.Button;
 
import java.time.Instant;
 
public class Main2Activity extends AppCompatActivity {
 
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main2);
        Button btn2=findViewById(R.id.btn2);
        btn2.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View view) {
                Intent intent=new Intent();
                intent.setClass(Main2Activity.this,Main3Activity.class);
                startActivity(intent);
            }
        });
        Button btn3=findViewById(R.id.btn3);
        btn3.setOnClickListener(new View.OnClickListener() {
        @Override
        public void onClick(View view) {
            Intent intent=new Intent();
            intent.setAction("android.intent.action.VIEW");
            intent.setData(Uri.parse("http://www.baidu.com"));
            startActivity(intent);
        }
        });
    }
}

 

 2.

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout 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:orientation="vertical"
    android:id="@+id/xb_1"
    tools:context=".Main4Activity">

    <EditText
        android:id="@+id/et_1"
        android:layout_width="200dp"
        android:layout_height="wrap_content"
        android:layout_marginTop="100dp"
        android:layout_marginLeft="100dp"
        android:layout_marginRight="100dp"
        android:inputType="number"
        android:gravity="center"
        android:textSize="20sp"/>

    <EditText
        android:id="@+id/et_2"
        android:layout_width="200dp"
        android:layout_height="wrap_content"
        android:layout_marginLeft="100dp"
        android:layout_marginRight="100dp"
        android:inputType="number"
        android:gravity="center"
        android:textSize="20sp"/>
    <LinearLayout
        android:id="@+id/xb_2"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_marginTop="20dp"
        android:layout_marginLeft="20dp"
        android:layout_marginRight="20dp"
        android:orientation="horizontal">
        <Button
            android:id="@+id/btn_1"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:text="加(+)"/>
        <Button
            android:id="@+id/btn_2"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:text="减(-)"/>
        <Button
            android:id="@+id/btn_3"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:text="乘(*)"/>
         <Button
             android:id="@+id/btn_4"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:text="除(/)"/>
    </LinearLayout>
    <TextView
        android:id="@+id/tv_1"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_marginTop="50dp"
        android:layout_marginLeft="150dp"
        android:layout_marginRight="150dp"
        android:textSize="30sp"
        android:gravity="center"
        android:textColor="#06C6F7"
        android:text="结果为"/>

</LinearLayout>

import androidx.appcompat.app.AppCompatActivity;

import android.content.Intent;
import android.os.Bundle;
import android.view.View;
import android.widget.EditText;
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.b_1 ).setOnClickListener( new View.OnClickListener() {
            @Override
            public void onClick(View view) {
                String num1=((EditText)(findViewById( R.id.et_1 ))).getText().toString();//获取et_1上面的文本，并转成字符串
                String num2=((EditText)(findViewById( R.id.et_2 ))).getText().toString();//获取et_2上面的文本，并转成字符串
                int n1= Integer.parseInt( num1 );
                int n2=Integer.parseInt( num2 );
                int sum=n1+n2;
                TextView tv1=findViewById( R.id.tv2 );//获取TextView控件
                tv1.setText( "结果是"+sum );

            }
        } );
        findViewById( R.id.b_2 ).setOnClickListener( new View.OnClickListener() {
            @Override
            public void onClick(View view) {
                String num1=((EditText)(findViewById( R.id.et_1 ))).getText().toString();
                String num2=((EditText)(findViewById( R.id.et_2 ))).getText().toString();
                int n1=Integer.parseInt( num1 );
                int n2=Integer.parseInt( num2 );
                int sum=n1-n2;
                TextView tv1=findViewById( R.id.tv2 );
                tv1.setText("结果是"+sum);
            }
        } );
        findViewById( R.id.b_3 ).setOnClickListener( new View.OnClickListener() {
            @Override
            public void onClick(View view) {
                String num1=((EditText)(findViewById( R.id.et_1 ))).getText().toString();
                String num2=((EditText)(findViewById( R.id.et_2 ))).getText().toString();
                int n1=Integer.parseInt( num1 );
                int n2=Integer.parseInt( num2 );
                int sum=n1*n2;
                TextView tv1=findViewById( R.id.tv2 );
                tv1.setText("结果是"+sum);
            }
        } );
        findViewById( R.id.b_4 ).setOnClickListener( new View.OnClickListener() {
            @Override
            public void onClick(View view) {
                String num1=((EditText)(findViewById( R.id.et_1 ))).getText().toString();
                String num2=((EditText)(findViewById( R.id.et_2 ))).getText().toString();
                int n1=Integer.parseInt( num1 );
                int n2=Integer.parseInt( num2 );
                int sum=n1*n2;
                TextView tv1=findViewById( R.id.tv2 );
                tv1.setText("结果是"+sum);
            }
        } );
        findViewById( R.id.b_4).setOnClickListener( new View.OnClickListener() {
            @Override
            public void onClick(View view) {
                String num1=((EditText)(findViewById( R.id.et_1 ))).getText().toString();
                String num2=((EditText)(findViewById( R.id.et_2 ))).getText().toString();
                int n1=Integer.parseInt( num1 );
                int n2=Integer.parseInt( num2 );
                int sum=n1/n2;
                TextView tv1=findViewById( R.id.tv2 );
                tv1.setText("结果是"+sum);
            }
        } );
    }
}