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

<?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>

package com.example.homework11;

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);
            }
        });
    }
}

<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>

package com.example.homework11;

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);
            }
        });
    }
}

<?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>

 

 

 

 

 

 2.在界面1做一个按钮开启浏览器访问百度

<?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">
    <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_2"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:background="#BE36E4"
        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="click1"/>


</LinearLayout>

package com.example.chap10;

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;


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);
            }
        });
    }
    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);
    }
}

 

 

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.aswork1;

import android.os.Bundle;
import android.util.Log;
import android.view.View;
import android.widget.Button;
import android.widget.EditText;
import android.widget.TextView;

import androidx.appcompat.app.AppCompatActivity;

public class MainActivity3 extends AppCompatActivity {
    EditText et1;
    EditText et2;
    Button btn1;
    Button btn2;
    Button btn3;
    Button btn4;
    TextView tv1;
    String str1;
    String str2;
    int a;
    int b;

    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main3);
        et1=findViewById(R.id.et1);
        et2=findViewById(R.id.et2);
        btn1=findViewById(R.id.btn1);
        btn2=findViewById(R.id.btn2);
        btn3=findViewById(R.id.btn3);
        btn4=findViewById(R.id.btn4);
        tv1=findViewById(R.id.tv1);
        btn1.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                str1=et1.getText().toString();
                str2=et2.getText().toString();
                a=Integer.parseInt(str1);
                b=Integer.parseInt(str2);
                String str3=""+(a+b);

                tv1.setText(str3);
            }
        });
        btn2.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                str1=et1.getText().toString();
                str2=et2.getText().toString();
                a=Integer.parseInt(str1);
                b=Integer.parseInt(str2);
                String str3=""+(a-b);

                tv1.setText(str3);
            }
        });
        btn3.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                str1=et1.getText().toString();
                str2=et2.getText().toString();
                a=Integer.parseInt(str1);
                b=Integer.parseInt(str2);
                String str3=""+(a*b);

                tv1.setText(str3);
            }
        });
        btn4.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                str1=et1.getText().toString();
                str2=et2.getText().toString();
                a=Integer.parseInt(str1);
                b=Integer.parseInt(str2);
                String str3=""+(a/b);

                tv1.setText(str3);
            }
        });
    }
}

<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    android:id="@+id/rl_1"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".MainActivity3"
    android:orientation="vertical">

    <EditText
        android:layout_width="match_parent"
        android:layout_height="50dp"
        android:id="@+id/et1"/>
    <EditText
        android:layout_width="match_parent"
        android:layout_height="50dp"
        android:id="@+id/et2"/>
    <Button
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:id="@+id/btn1"
        android:text="加"/>
    <Button
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:id="@+id/btn2"
        android:text="减"/>

    <Button
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:id="@+id/btn3"
        android:text="乘"/>
    <Button
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:id="@+id/btn4"
        android:text="除"/>
    <TextView
        android:layout_width="match_parent"
        android:layout_height="100dp"
        android:id="@+id/tv1"/>




</LinearLayout>