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">
<Button
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="显式意图"
android:layout_gravity="center"
android:onClick="onClick"/>
</LinearLayout>
<?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">
<Button
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="隐式意图"
android:onClick="onClick"
android:layout_gravity="center"/>
</LinearLayout>
<?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">
<TextView
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="第三个界面"
android:textSize="100px"
android:layout_gravity="center"/>
</LinearLayout>
package com.example.work4_1;
import androidx.appcompat.app.AppCompatActivity;
import android.content.Intent;
import android.view.View;
import android.content.Intent;
import android.os.Bundle;
public class MainActivity extends AppCompatActivity {
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
}
public void onClick(View v){
Intent intent = new Intent(MainActivity.this,SecondActivity.class);
startActivity(intent);
}
}
package com.example.work4_1;
import androidx.appcompat.app.AppCompatActivity;
import android.content.Intent;
import android.os.Bundle;
import android.view.View;
public class SecondActivity extends AppCompatActivity {
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_second);
}
public void onClick(View v){
Intent intent = new Intent();
intent.setAction("cn.itcast.START_ACTIVITY");
startActivity(intent);
}
}
<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
package="com.example.work4_1">
<application
android:allowBackup="true"
android:icon="@mipmap/ic_launcher"
android:label="@string/app_name"
android:roundIcon="@mipmap/ic_launcher_round"
android:supportsRtl="true"
android:theme="@style/AppTheme">
<activity android:name=".ThirdActivity">
<intent-filter>
<action android:name="cn.itcast.START_ACTIVITY" />
<category android:name="android.intent.category.DEFAULT" />
<!-- <data-->
<!-- android:mimeType="aa/bb"-->
<!-- android:scheme="mytestscheme" />-->
</intent-filter>
</activity>
<activity android:name=".SecondActivity">
<intent-filter>
<action android:name="cn.itcast.SECOND_ACTIVITY" />
<category android:name="android.intent.category.DEFAULT" />
<!-- <data-->
<!-- android:mimeType="aa/bb"-->
<!-- android:scheme="mytestscheme" />-->
</intent-filter>
</activity>
<activity android:name=".MainActivity">
<intent-filter>
<action android:name="android.intent.action.MAIN" />
<category android:name="android.intent.category.LAUNCHER" />
</intent-filter>
</activity>
</application>
</manifest>
2.在界面1做一个按钮开启浏览器访问百度
package com.example.work4_1;
import androidx.appcompat.app.AppCompatActivity;
import android.content.Intent;
import android.net.Uri;
import android.view.View;
import android.content.Intent;
import android.os.Bundle;
public class MainActivity extends AppCompatActivity {
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
}
public void onClick(View v){
Intent intent= new Intent();
intent.setAction("android.intent.action.VIEW");
intent.setData(Uri.parse("http://www.baidu.com"));
startActivity(intent);
}
}
package com.example.work4_1;
import androidx.appcompat.app.AppCompatActivity;
import android.content.Intent;
import android.net.Uri;
import android.view.View;
import android.content.Intent;
import android.os.Bundle;
public class MainActivity extends AppCompatActivity {
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
}
public void onClick(View v){
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">
<Button
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="打开百度"
android:layout_gravity="center"
android:onClick="onClick"/>
</LinearLayout>
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: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">
<EditText
android:id="@+id/et1"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:layout_marginTop="50dp"
android:gravity="center"
android:textSize="50dp"/>
<EditText
android:id="@+id/et2"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:layout_marginTop="50dp"
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="80dp"
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="80dp"
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="80dp"
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="80dp"
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="80dp"
/>
<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="80dp"
/>
</RelativeLayout>
package com.example.work4_3;
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 add(View v){
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);
TextView tx2=(TextView)findViewById(R.id.tx2);
int sum = n1+n2;
tx2.setText(String.valueOf(sum));
}
public void reduce(View v){
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);
TextView tx2=(TextView)findViewById(R.id.tx2);
int sum = n1-n2;
tx2.setText(String.valueOf(sum));
}
public void ride(View v){
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);
TextView tx2=(TextView)findViewById(R.id.tx2);
int sum = n1*n2;
tx2.setText(String.valueOf(sum));
}
public void except(View v){
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);
TextView tx2=(TextView)findViewById(R.id.tx2);
int sum = n1/n2;
tx2.setText(String.valueOf(sum));
}
}
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