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
要求，按钮点击功能使用setOnclickListener方式

<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_height="match_parent"
    android:layout_width="match_parent"
    >
<Button
    android:id="@+id/but_1"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:text="显示意图显示界面二"
    android:textSize="25dp"
    android:onClick="click1"/>
</RelativeLayout>

<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
     android:layout_height="match_parent"
    android:layout_width="match_parent">
    <Button
        android:id="@+id/bit_1"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="界面二"
        android:textSize="25dp"
        android:layout_centerHorizontal="true"/>
</RelativeLayout>

<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_height="match_parent"
    android:layout_width="match_parent">
    <Button
        android:id="@+id/bit_1"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="界面三"
        android:textSize="25dp"
        android:layout_centerHorizontal="true"/>
</RelativeLayout>

package cn.itcast.chap04;

import androidx.appcompat.app.AppCompatActivity;

import android.content.Intent;
import android.net.Uri;
import android.os.Bundle;
import android.util.Log;
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 );

    }
    
   public void click1(View view){
        Intent intent=new Intent( this,Main2Activity.class );
        startActivity( intent );

    }
}

<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
     android:layout_height="match_parent"
    android:layout_width="match_parent">
    <Button
        android:id="@+id/but_1"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="隐式意图显示界面三"
        android:textSize="25dp"
        android:onClick="click2_3"/>

</RelativeLayout>

package cn.itcast.chap04;

import androidx.appcompat.app.AppCompatActivity;

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

public class Main2Activity extends AppCompatActivity {

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate( savedInstanceState );
        setContentView( R.layout.activity_main2 );
    }
    public void click2_3(View view){
        Intent intent=new Intent(  );
        intent.setAction( "start_activity" );
        startActivity( intent );
    }


}

<activity android:name=".Main3Activity">
    <intent-filter>
        <action android:name="start_activity" />

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

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

</activity>

2.在界面1做一个按钮开启浏览器访问百度

<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_height="match_parent"
    android:layout_width="match_parent"
    >
    <Button
        android:id="@+id/but_1"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="界面一"
        android:textSize="25dp"
       android:layout_centerHorizontal="true"/>
<Button
    android:id="@+id/but_4"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:text="隐式意图打开浏览器"
    android:textSize="25dp"
    android:onClick="click3"
    android:layout_below="@id/but_3"/>
</RelativeLayout>

package cn.itcast.chap04;

import androidx.appcompat.app.AppCompatActivity;

import android.content.Intent;
import android.net.Uri;
import android.os.Bundle;
import android.util.Log;
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 );

    }
 public void click3(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"
    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=".Main2Activity"
    android:layout_margin="20dp">
    <TextView
        android:id="@+id/tv1"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="数字:"
        android:textColor="#000000"
        android:textSize="20sp"
        android:layout_marginTop="15dp"/>
    <EditText
        android:id="@+id/et1"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:hint="请输入数字"
        android:textSize="25sp"
        android:textColorHint="#E91313"
        android:maxLines="1"
        android:scrollHorizontally="true"
        android:layout_toRightOf="@+id/tv1"/>
    <TextView
        android:id="@+id/tv2"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="数字:"
        android:textColor="#000000"
        android:textSize="20sp"
        android:layout_marginTop="25dp"
        android:layout_below="@id/tv1"/>
    <EditText
        android:id="@+id/et2"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:hint="请输入数字"
        android:textSize="25sp"
        android:textColorHint="#E91313"
        android:maxLines="1"
        android:scrollHorizontally="true"
        android:layout_toRightOf="@+id/tv1"
        android:layout_below="@id/et1"/>
    <Button
        android:id="@+id/btn_1"
        android:layout_width="100dp"
        android:layout_height="100dp"
        android:text="+"
        android:textColor="#000000"
        android:textSize="50sp"
        android:layout_below="@id/et2"
        android:layout_marginTop="100dp"
        android:layout_margin="10dp"
        android:layout_alignLeft="@id/et2" />
    <Button
        android:id="@+id/btn_2"
        android:layout_width="100dp"
        android:layout_height="100dp"
        android:text="-"
        android:textColor="#000000"
        android:textSize="50sp"
        android:layout_below="@id/et2"
        android:layout_toRightOf="@id/btn_1" />
    <Button
        android:id="@+id/btn_3"
        android:layout_width="100dp"
        android:layout_height="100dp"
        android:layout_below="@id/btn_1"
        android:layout_margin="10dp"
        android:text="*"
        android:textColor="#000000"
        android:textSize="50sp"
        android:layout_alignLeft="@id/et2" />
    <Button
        android:id="@+id/btn_4"
        android:layout_width="100dp"
        android:layout_height="100dp"
        android:layout_below="@id/btn_1"
        android:layout_toRightOf="@id/btn_3"
        android:text="/"
        android:textColor="#000000"
        android:textSize="50sp"
        android:layout_alignTop="@id/btn_3" />
    <TextView
        android:id="@+id/tv3"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_below="@id/btn_3"
        android:layout_margin="20dp"
        android:text="结果是："
        android:textSize="45sp"
        android:textColor="#000000"
        android:textStyle="italic"/>
</RelativeLayout>

package com.example.myapplication;

import androidx.appcompat.app.AppCompatActivity;

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

public class Main2Activity extends AppCompatActivity {

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main2);
        //+
        findViewById(R.id.btn_1).setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View view) {
                String num1=((EditText)(findViewById(R.id.et1))).getText().toString();
                String num2=((EditText)(findViewById(R.id.et2))).getText().toString();
                int n1=Integer.parseInt(num1);
                int n2=Integer.parseInt(num2);
                int n3=n1+n2;
                TextView tv1=(TextView)findViewById(R.id.tv3);
                tv1.setText("结果是"+n3);
            }
        });
        //-
        findViewById(R.id.btn_2).setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View view) {
                String num1=((EditText)(findViewById(R.id.et1))).getText().toString();
                String num2=((EditText)(findViewById(R.id.et2))).getText().toString();
                int n1=Integer.parseInt(num1);
                int n2=Integer.parseInt(num2);
                int n3=n1-n2;
                TextView tv1=(TextView)findViewById(R.id.tv3);
                tv1.setText("结果是"+n3);
            }
        });
        //*
        findViewById(R.id.btn_3).setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View view) {
                String num1=((EditText)(findViewById(R.id.et1))).getText().toString();
                String num2=((EditText)(findViewById(R.id.et2))).getText().toString();
                int n1=Integer.parseInt(num1);
                int n2=Integer.parseInt(num2);
                int n3=n1*n2;
                TextView tv1=(TextView)findViewById(R.id.tv3);
                tv1.setText("结果是"+n3);
            }
        });
        //除
        findViewById(R.id.btn_4).setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View view) {
                String num1=((EditText)(findViewById(R.id.et1))).getText().toString();
                String num2=((EditText)(findViewById(R.id.et2))).getText().toString();
                int n1=Integer.parseInt(num1);
                int n2=Integer.parseInt(num2);
                int n3=n1/n2;
                TextView tv1=(TextView)findViewById(R.id.tv3);
                tv1.setText("结果是"+n3);
            }
        });
    }
}