package com.example.myapplication;

import .AppCompatActivity;

import android.content.Intent;
import android.net.Uri;
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(.bt_1);
        btn1.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View view) {
                Intent intent=new Intent(MainActivity.this,Main2Activity.class);
                startActivity(intent);
            }
        });
    }
    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"?>
<LinearLayout xmlns:android="http:///apk/res/android"
    xmlns:app="http:///apk/res-auto"
    xmlns:tools="http:///tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:orientation="vertical"
    android:background="#F7DDFC"
    tools:context=".MainActivity">

    <Button
        android:id="@+id/bt_1"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:background="#77DDEB"
        android:text="显式意图开启界面2"
        android:textSize="20sp"
        android:layout_marginTop="20dp"
        android:layout_marginLeft="20dp"/>
    <Button
        android:id="@+id/bt_3"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:background="#56AEF5"
        android:text="开启浏览器访问百度"
        android:textSize="20sp"
        android:layout_marginTop="20dp"
        android:layout_marginLeft="20dp"
        android:padding="10dp"
        android:onClick="click3"/>

</LinearLayout>

Android第七周作业_显式

<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http:///apk/res/android"
    xmlns:app="http:///apk/res-auto"
    xmlns:tools="http:///tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".MainActivity">

    <EditText
        android:id="@+id/et1"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:layout_marginTop="30dp"
        android:gravity="center"
        android:textSize="50dp"/>
    <EditText
        android:id="@+id/et2"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:layout_marginTop="30dp"
        android:layout_below="@id/et1"
        android:gravity="center"
        android:textSize="50dp"/>
    <Button
        android:id="@+id/add"
        android:layout_width="200px"
        android:layout_height="200px"
        android:text="+"
        android:textSize="50dp"
        android:layout_below="@id/et2"
        android:layout_marginTop="30dp"
        android:onClick="add"/>
    <Button
        android:id="@+id/reduce"
        android:layout_width="200px"
        android:layout_height="200px"
        android:text="-"
        android:textSize="50dp"
        android:layout_below="@id/et2"
        android:layout_toRightOf="@id/add"
        android:layout_marginTop="30dp"
        android:layout_marginLeft="30dp"
        android:onClick="reduce"/>
    <Button
        android:id="@+id/ride"
        android:layout_width="200px"
        android:layout_height="200px"
        android:text="*"
        android:textSize="50dp"
        android:layout_below="@id/et2"
        android:layout_toLeftOf="@id/except"
        android:layout_marginTop="30dp"
        android:onClick="ride"/>
    <Button
        android:id="@+id/except"
        android:layout_width="200px"
        android:layout_height="200px"
        android:text="/"
        android:textSize="50dp"
        android:layout_below="@id/et2"
        android:layout_alignParentRight="true"
        android:layout_marginTop="30dp"
        android:layout_marginLeft="30dp"
        android:onClick="except"/>
    <!--        android:layout_toRightOf="@id/ride"-->


    <TextView
        android:id="@+id/tx1"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="结果是："
        android:textSize="50dp"
        android:layout_below="@id/add"
        android:layout_marginTop="30dp"
        />
    <TextView
        android:id="@+id/tx2"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text=""
        android:textSize="50dp"
        android:layout_below="@id/add"
        android:layout_toRightOf="@id/tx1"
        android:layout_marginTop="30dp"
        />

</RelativeLayout>
package com.example.myapplication;

import .AppCompatActivity;

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);
    }


    public void add(View v){
        String num1=((EditText)(findViewById(.et1))).getText().toString();
        String num2=((EditText)(findViewById(.et2))).getText().toString();
        int n1=Integer.parseInt(num1);
        int n2=Integer.parseInt(num2);
        TextView tx2=(TextView)findViewById(.tx2);
        int sum = n1+n2;
        tx2.setText(String.valueOf(sum));
    }
    public void reduce(View v){
        String num1=((EditText)(findViewById(.et1))).getText().toString();
        String num2=((EditText)(findViewById(.et2))).getText().toString();
        int n1=Integer.parseInt(num1);
        int n2=Integer.parseInt(num2);
        TextView tx2=(TextView)findViewById(.tx2);
        int sum = n1-n2;
        tx2.setText(String.valueOf(sum));
    }
    public void ride(View v){
        String num1=((EditText)(findViewById(.et1))).getText().toString();
        String num2=((EditText)(findViewById(.et2))).getText().toString();
        int n1=Integer.parseInt(num1);
        int n2=Integer.parseInt(num2);
        TextView tx2=(TextView)findViewById(.tx2);
        int sum = n1*n2;
        tx2.setText(String.valueOf(sum));
    }
    public void except(View v){
        String num1=((EditText)(findViewById(.et1))).getText().toString();
        String num2=((EditText)(findViewById(.et2))).getText().toString();
        int n1=Integer.parseInt(num1);
        int n2=Integer.parseInt(num2);
        TextView tx2=(TextView)findViewById(.tx2);
        int sum = n1/n2;
        tx2.setText(String.valueOf(sum));
    }

}

Android第七周作业_xml_02