第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
要求，按钮点击功能使用setOnclickListener方式

2.在界面1做一个按钮开启浏览器访问百度

package com.example.app6;

import android.net.Uri;
import android.os.Bundle;
import android.app.Activity;
import android.content.Intent;
import android.view.Menu;
import android.view.View;
import android.view.View.OnClickListener;
import android.widget.Button;

public class MainActivity extends Activity {

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        Button bt1=(Button)findViewById(R.id.bt1);
        Button bt2=(Button)findViewById(R.id.bt2);
        
        bt1.setOnClickListener(new OnClickListener() {
            
            @Override
            public void onClick(View v) {
                // TODO Auto-generated method stub
                Intent intent=new Intent(MainActivity.this,Activity2.class);
                startActivity(intent);
            }
        });
        
      
    }
    public void click2(View view){
        Intent intent=new Intent();
        intent.setAction("android.intent.action.VIEW");
        intent.setData(Uri.parse("http://www.baidu.com"));
        startActivity(intent);
    }
 
}

package com.example.app6;

import android.os.Bundle;
import android.app.Activity;
import android.content.Intent;
import android.view.Menu;
import android.view.View;
import android.view.View.OnClickListener;
import android.widget.Button;

public class Activity2 extends Activity {

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_activity2);
         Button bt2=(Button)findViewById(R.id.bt2);
            bt2.setOnClickListener(new OnClickListener() {
                
                @Override
                public void onClick(View v) {
                    // TODO Auto-generated method stub
                    Intent intent=new Intent();
                    intent.setAction("com.lrp.start");
                    intent.addCategory("android.intent.category.DEFAULT");
                    startActivity(intent);
                }
            });
    }

}　　

package com.example.app6;

import android.os.Bundle;
import android.app.Activity;
import android.view.Menu;

public class Activity3 extends Activity {

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_activity3);
    }



}

<RelativeLayout 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:paddingBottom="@dimen/activity_vertical_margin"
    android:paddingLeft="@dimen/activity_horizontal_margin"
    android:paddingRight="@dimen/activity_horizontal_margin"
    android:paddingTop="@dimen/activity_vertical_margin"
    tools:context=".MainActivity" >
    <Button 
        android:id="@+id/bt1"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="开启界面二"
        />
    
      <Button 
        android:id="@+id/bt2"
        android:onClick="click2"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="开启百度"
        android:layout_below="@id/bt1"
        />
    
</RelativeLayout>

<RelativeLayout 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:paddingBottom="@dimen/activity_vertical_margin"
    android:paddingLeft="@dimen/activity_horizontal_margin"
    android:paddingRight="@dimen/activity_horizontal_margin"
    android:paddingTop="@dimen/activity_vertical_margin"
    tools:context=".Activity2" >
    <Button 
        android:id="@+id/bt2"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="开启界面三"
        />
</RelativeLayout>　

<RelativeLayout 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:paddingBottom="@dimen/activity_vertical_margin"
    android:paddingLeft="@dimen/activity_horizontal_margin"
    android:paddingRight="@dimen/activity_horizontal_margin"
    android:paddingTop="@dimen/activity_vertical_margin"
    tools:context=".Activity3" >

    <TextView
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="@string/hello_world" />

</RelativeLayout>　

<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
    package="com.example.app6"
    android:versionCode="1"
    android:versionName="1.0" >

    <uses-sdk
        android:minSdkVersion="8"
        android:targetSdkVersion="17" />

    <application
        android:allowBackup="true"
        android:icon="@drawable/ic_launcher"
        android:label="@string/app_name"
        android:theme="@style/AppTheme" >
        <activity
            android:name="com.example.app6.MainActivity"
            android:label="@string/app_name" >
            <intent-filter>
                <action android:name="android.intent.action.MAIN" />

                <category android:name="android.intent.category.LAUNCHER" />
            </intent-filter>
        </activity>
        <activity
            android:name="com.example.app6.Activity2"
            android:label="@string/title_activity_activity2" >
        </activity>
        <activity
            android:name="com.example.app6.Activity3"
            android:label="@string/title_activity_activity3" >
            
              <intent-filter>
                <action android:name="com.lrp.start" />

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

</manifest>

　

 

 

 

 

 

 

　

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

<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout 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"
    >

    <EditText
        android:id="@+id/ed1"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:layout_marginEnd="50dp"
        android:layout_marginStart="10dp"
        android:layout_marginTop="20dp"
        android:ems="10"
        android:hint="第一个数"
        android:maxLines="2"
        android:textStyle="italic"
        android:layout_marginRight="50dp"
        android:layout_marginLeft="10dp">
    </EditText>

    <EditText
        android:id="@+id/ed2"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:layout_marginEnd="50dp"
        android:layout_marginStart="10dp"
        android:layout_marginTop="70dp"
        android:hint="第二个数"
        android:textStyle="italic"
        android:layout_marginRight="50dp"
        android:layout_marginLeft="10dp" />

    <Button
        android:id="@+id/btn_1"
        android:layout_width="80dp"
        android:layout_height="80dp"
        android:layout_alignParentLeft="true"
        android:layout_below="@+id/ed2"
        android:layout_marginTop="14dp"
        android:text="+"
        android:textSize="30dp"
        android:onClick="SUM"/>
    <Button
        android:id="@+id/btn_2"
        android:layout_width="80dp"
        android:layout_height="80dp"
        android:layout_below="@+id/ed2"
        android:layout_marginTop="14dp"
        android:layout_marginLeft="100dp"
        android:text="-"
        android:textSize="30dp"
        android:onClick="SUB"/>
    <Button
        android:id="@+id/btn_3"
        android:layout_width="80dp"
        android:layout_height="80dp"
        android:layout_below="@+id/ed2"
        android:layout_marginTop="14dp"
        android:layout_marginLeft="200dp"
        android:text="*"
        android:textSize="30dp"
        android:onClick="MUL"/>
    <Button
        android:id="@+id/btn_4"
        android:layout_width="80dp"
        android:layout_height="80dp"
        android:layout_below="@+id/ed2"
        android:layout_marginTop="14dp"
        android:layout_marginLeft="300dp"
        android:text="/"
        android:textSize="30dp"
        android:onClick="DIV"/>
    <TextView
        android:id="@+id/tv1"
        android:layout_width="match_parent"
        android:layout_height="50dp"
        android:text="结果是:"
        android:textSize="30dp"
        android:layout_marginTop="220dp"></TextView>
</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 MainActivity extends AppCompatActivity {

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
    }
    public void SUM(View v) {
        // TODO Auto-generated method stub
        EditText ed1=(EditText)findViewById(R.id.ed1);
        EditText ed2=(EditText)findViewById(R.id.ed2);
        TextView tv1=(TextView)findViewById(R.id.tv1);
        double num1=0;
        double num2=0;
        double ans=0;
        String numed1=ed1.getText().toString();
        String numed2=ed2.getText().toString();
        num1=Double.parseDouble(numed1);
        num2=Double.parseDouble(numed2);
        ans=num1+num2;
        tv1.setText(String.valueOf(ans));
    }
    public void SUB(View v) {
        // TODO Auto-generated method stub
        EditText ed1=(EditText)findViewById(R.id.ed1);
        EditText ed2=(EditText)findViewById(R.id.ed2);
        TextView tv1=(TextView)findViewById(R.id.tv1);
        double num1=0;
        double num2=0;
        double ans=0;
        String numed1=ed1.getText().toString();
        String numed2=ed2.getText().toString();
        num1=Double.parseDouble(numed1);
        num2=Double.parseDouble(numed2);
        ans=num1-num2;
        tv1.setText(String.valueOf(ans));
    }
    public void MUL(View v) {
        // TODO Auto-generated method stub
        EditText ed1=(EditText)findViewById(R.id.ed1);
        EditText ed2=(EditText)findViewById(R.id.ed2);
        TextView tv1=(TextView)findViewById(R.id.tv1);
        double num1=0;
        double num2=0;
        double ans=0;
        String numed1=ed1.getText().toString();
        String numed2=ed2.getText().toString();
        num1=Double.parseDouble(numed1);
        num2=Double.parseDouble(numed2);
        ans=num1*num2;
        tv1.setText(String.valueOf(ans));
    }
    public void DIV(View v) {
        // TODO Auto-generated method stub
        EditText ed1=(EditText)findViewById(R.id.ed1);
        EditText ed2=(EditText)findViewById(R.id.ed2);
        TextView tv1=(TextView)findViewById(R.id.tv1);
        double num1=0;
        double num2=0;
        double ans=0;
        String numed1=ed1.getText().toString();
        String numed2=ed2.getText().toString();
        num1=Double.parseDouble(numed1);
        num2=Double.parseDouble(numed2);
        ans=num1/num2;
        tv1.setText(String.valueOf(ans));
    }
}