7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，在界面1做一个按钮开启浏览器访问百度

<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"
    tools:context=".MainActivity"
    android:orientation="vertical" >

    <Button
        android:id="@+id/bt1"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="显式意图开启界面2"
        android:onClick="click1"
        />
    <Button
        android:id="@+id/bt2"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="隐式意图开启界面3"
        android:onClick="click2"
        />
    <Button
        android:id="@+id/bt3"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="开启浏览器访问百度"
        android:onClick="click3"
        />

</LinearLayout>

package com.example.myapplication7;

import android.net.Uri;
import android.os.Bundle;
import android.app.Activity;
import android.content.Intent;
import android.util.Log;
import android.view.Menu;
import android.view.View;

public class MainActivity extends Activity {

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        Log.e("MainActivity", "调用oncreate");

    }

    @Override
    protected void onStart() {
        super.onStart();
        Log.e("MainActivity", "调用onstart");
    }
    @Override
    protected void onResume() {
        super.onResume();
        Log.e("MainActivity", "调用onresume");
    }
    @Override
    protected void onPause() {
        // TODO Auto-generated method stub
        super.onPause();
        Log.e("MainActivity", "调用onpause");
    }

    @Override
    protected void onStop() {
        // TODO Auto-generated method stub
        super.onStop();
        Log.e("MainActivity", "调用onstop");
    }

    @Override
    protected void onDestroy() {
        // TODO Auto-generated method stub
        super.onDestroy();
        Log.e("MainActivity", "调用ondestroy");
    }

    @Override
    protected void onRestart() {
        // TODO Auto-generated method stub
        super.onRestart();
        Log.e("MainActivity", "调用onRestart");
    }

    public void click1(View view){
        Intent intent=new Intent(this,Main2Activity7.class);
        startActivity(intent);

    }

    public void click2(View view){
        Intent intent=new Intent();
        intent.setAction("cn.itcast.START_ACTIVITY");
        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://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=".Main2Activity7">

    <Button
        android:id="@+id/bu_2"
        android:layout_width="wrap_content"
        android:layout_height="80dp"
        android:layout_margin="20dp"
        android:text="界面2"
        android:textSize="50sp" />

</LinearLayout>
package com.example.myapplication7;

import androidx.appcompat.app.AppCompatActivity;
import android.content.Intent;
import android.os.Bundle;
import android.view.View;
import android.widget.Button;
public class Main2Activity7 extends AppCompatActivity {

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main27);


    }
}

<?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=".Main2Activity7_2"
    android:orientation="vertical">
    <Button
        android:id="@+id/bu_3"
        android:layout_width="wrap_content"
        android:layout_height="80dp"
        android:layout_margin="20dp"
        android:text="界面3"
        android:textSize="50sp" />
</LinearLayout>

package com.example.myapplication7;
import androidx.appcompat.app.AppCompatActivity;
import android.content.Intent;
import android.os.Bundle;
import android.view.View;
import android.widget.Button;

public class Main2Activity7_2 extends AppCompatActivity {

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main2_activity7_2);

    }
}

 

 

 

2. 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"
    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"
    android:id="@+id/a_1"
    tools:context=".MainActivity">

    <EditText
        android:id="@+id/et_1"
        android:layout_width="100dp"
        android:layout_height="wrap_content"
        android:hint="请输入一个数"
        android:layout_margin="100dp"
        android:inputType="number"
        android:gravity="center"
        android:textSize="20sp"/>
    <EditText
        android:id="@+id/et_2"
        android:layout_width="100dp"
        android:layout_height="wrap_content"
        android:hint="请输入一个数"
        android:layout_marginLeft="100dp"
        android:inputType="number"
        android:gravity="center"
        android:textSize="20sp" />
    <LinearLayout
        android:id="@+id/a_2"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:orientation="horizontal"
        android:layout_marginTop="20dp"
        android:layout_marginRight="20dp"
        android:layout_marginLeft="20dp">
        <Button
            android:id="@+id/bt_1"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:layout_marginTop="50dp"
            android:textSize="50dp"
            android:text="+"
            />
        <Button
            android:id="@+id/bt_2"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:layout_marginTop="50dp"
            android:textSize="50dp"
            android:text="-"
            />
        <Button
            android:id="@+id/bt_3"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:text="*"
            android:layout_marginTop="50dp"
            android:textSize="50dp"
            />
        <Button
            android:id="@+id/bt_4"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:text="/"
            android:layout_marginTop="50dp"
            android:textSize="50dp"
            />
    </LinearLayout>
    <TextView
        android:id="@+id/tv_1"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="结果="
        android:textSize="40sp"
        android:textColor="#00000F"
        android:layout_marginLeft="20dp"
        android:layout_marginRight="150dp"
        android:layout_marginTop="50dp"
        android:gravity="center"/>


</LinearLayout>

package com.example.myapplication7;
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.bt_1).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 tv_1=findViewById(R.id.tv_1);
                tv_1.setText("结果="+sum);
            }
        });
        findViewById(R.id.bt_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 tv_1=findViewById(R.id.tv_1);
                tv_1.setText("结果="+sum);
            }
        });
        findViewById(R.id.bt_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 tv_1=findViewById(R.id.tv_1);
                tv_1.setText("结果="+sum);
            }
        });
        findViewById(R.id.bt_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 tv_1=findViewById(R.id.tv_1);
                tv_1.setText("结果="+sum);
            }
        });
    }
}