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
1 <?xml version="1.0" encoding="utf-8"?> 2 <LinearLayout xmlns:android="http://schemas.android.com/apk/res/android" 3 xmlns:app="http://schemas.android.com/apk/res-auto" 4 xmlns:tools="http://schemas.android.com/tools" 5 android:layout_width="match_parent" 6 android:layout_height="match_parent" 7 android:orientation="vertical" 8 tools:context=".MainActivity"> 9 10 <Button 11 android:id="@+id/bt_1" 12 android:layout_width="wrap_content" 13 android:layout_height="wrap_content" 14 android:background="#F2B4FC" 15 android:text="显示意图开启界面2" 16 android:textSize="20sp" 17 android:textColor="#000000" 18 android:layout_marginTop="20dp" 19 android:layout_marginLeft="10dp"/> 20 21 </LinearLayout>
1 package com.example.Lwk1; 2 3 import androidx.appcompat.app.AppCompatActivity; 4 5 import android.content.Intent; 6 import android.os.Bundle; 7 import android.view.View; 8 import android.widget.Button; 9 10 public class MainActivity extends AppCompatActivity { 11 12 @Override 13 protected void onCreate(Bundle savedInstanceState) { 14 super.onCreate(savedInstanceState); 15 setContentView(R.layout.activity_main); 16 Button btn1=(Button)findViewById(R.id.bt_1); 17 btn1.setOnClickListener(new View.OnClickListener() { 18 @Override 19 public void onClick(View view) { 20 Intent intent=new Intent(MainActivity.this,Main2Activity.class); 21 startActivity(intent); 22 } 23 }); 24 } 25 }
1 <LinearLayout xmlns:android="http://schemas.android.com/apk/res/android" 2 xmlns:app="http://schemas.android.com/apk/res-auto" 3 xmlns:tools="http://schemas.android.com/tools" 4 android:layout_width="match_parent" 5 android:layout_height="match_parent" 6 android:orientation="vertical" 7 tools:context=".Main2Activity"> 8 9 <Button 10 android:id="@+id/bt_2" 11 android:layout_width="wrap_content" 12 android:layout_height="wrap_content" 13 android:background="#EEA6BF" 14 android:text="隐式意图开启界面3" 15 android:textSize="20sp" 16 android:textColor="#000000" 17 android:layout_marginLeft="10dp" 18 android:layout_marginTop="20dp"/> 19 20 </LinearLayout>
1 package com.example.Lwk1; 2 3 import androidx.appcompat.app.AppCompatActivity; 4 5 import android.content.Intent; 6 import android.os.Bundle; 7 import android.view.View; 8 import android.widget.Button; 9 10 public class Main2Activity extends AppCompatActivity { 11 12 @Override 13 protected void onCreate(Bundle savedInstanceState) { 14 super.onCreate(savedInstanceState); 15 setContentView(R.layout.activity_main2); 16 Button btn2=(Button)findViewById(R.id.bt_2); 17 btn2.setOnClickListener(new View.OnClickListener() { 18 @Override 19 public void onClick(View view) { 20 Intent intent=new Intent(); 21 intent.setAction("com.ym.second"); 22 startActivity(intent); 23 } 24 }); 25 } 26 }
1 <?xml version="1.0" encoding="utf-8"?> 2 <RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android" 3 xmlns:app="http://schemas.android.com/apk/res-auto" 4 xmlns:tools="http://schemas.android.com/tools" 5 android:layout_width="match_parent" 6 android:layout_height="match_parent" 7 android:background="#A5D4FA" 8 tools:context=".Main3Activity"> 9 10 <TextView 11 android:id="@+id/tv_1" 12 android:layout_width="wrap_content" 13 android:layout_height="wrap_content" 14 android:text="界面3" 15 android:textSize="20sp" 16 android:textColor="#000000"/> 17 18 </RelativeLayout>
1 <activity android:name=".Main3Activity"> 2 <intent-filter> 3 <action android:name="com.ym.second" /> 4 5 <category android:name="android.intent.category.DEFAULT" /> 6 </intent-filter> 7 </activity> 8 <activity android:name=".Main2Activity" > 9 </activity> 10 <activity android:name=".MainActivity"> 11 <intent-filter> 12 <action android:name="android.intent.action.MAIN" /> 13 14 <category android:name="android.intent.category.LAUNCHER" /> 15 </intent-filter> 16 </activity>
2.在界面1做一个按钮开启浏览器访问百度
1 <?xml version="1.0" encoding="utf-8"?> 2 <LinearLayout xmlns:android="http://schemas.android.com/apk/res/android" 3 xmlns:app="http://schemas.android.com/apk/res-auto" 4 xmlns:tools="http://schemas.android.com/tools" 5 android:layout_width="match_parent" 6 android:layout_height="match_parent" 7 android:orientation="vertical" 8 android:background="#F7DDFC" 9 tools:context=".MainActivity"> 10 11 <Button 12 android:id="@+id/bt_1" 13 android:layout_width="wrap_content" 14 android:layout_height="wrap_content" 15 android:background="#77DDEB" 16 android:text="显式意图开启界面2" 17 android:textSize="20sp" 18 android:layout_marginTop="20dp" 19 android:layout_marginLeft="20dp"/> 20 <Button 21 android:id="@+id/bt_3" 22 android:layout_width="wrap_content" 23 android:layout_height="wrap_content" 24 android:background="#56AEF5" 25 android:text="开启浏览器访问百度" 26 android:textSize="20sp" 27 android:layout_marginTop="20dp" 28 android:layout_marginLeft="20dp" 29 android:padding="10dp" 30 android:onClick="click3"/> 31 32 </LinearLayout>
1 package com.example.Lwk2; 2 3 import androidx.appcompat.app.AppCompatActivity; 4 5 import android.content.Intent; 6 import android.net.Uri; 7 import android.os.Bundle; 8 import android.view.View; 9 import android.widget.Button; 10 11 public class MainActivity extends AppCompatActivity { 12 13 @Override 14 protected void onCreate(Bundle savedInstanceState) { 15 super.onCreate(savedInstanceState); 16 setContentView(R.layout.activity_main); 17 Button btn1=(Button)findViewById(R.id.bt_1); 18 btn1.setOnClickListener(new View.OnClickListener() { 19 @Override 20 public void onClick(View view) { 21 Intent intent=new Intent(MainActivity.this,Main2Activity.class); 22 startActivity(intent); 23 } 24 }); 25 } 26 public void click3(View view){ 27 Intent intent=new Intent(); 28 intent.setAction("android.intent.action.VIEW"); 29 intent.setData(Uri.parse("http://www.baidu.com")); 30 startActivity(intent); 31 } 32 }
3.2个edittext,4个按钮一个textview,实现简单计算器。
1 <?xml version="1.0" encoding="utf-8"?> 2 <LinearLayout xmlns:android="http://schemas.android.com/apk/res/android" 3 xmlns:app="http://schemas.android.com/apk/res-auto" 4 xmlns:tools="http://schemas.android.com/tools" 5 android:layout_width="match_parent" 6 android:layout_height="match_parent" 7 android:orientation="vertical" 8 android:id="@+id/a_1" 9 android:background="#F1B3FC" 10 tools:context=".MainActivity"> 11 <TextView 12 android:id="@+id/tv_1" 13 android:layout_width="wrap_content" 14 android:layout_height="wrap_content" 15 android:text="计算器" 16 android:textSize="25dp" 17 android:layout_margin="20dp" /> 18 19 <EditText 20 android:id="@+id/et_1" 21 android:layout_width="200dp" 22 android:layout_height="wrap_content" 23 android:hint="请输入一个数" 24 android:layout_marginLeft="100dp" 25 android:layout_marginRight="100dp" 26 android:layout_marginTop="100dp" 27 android:inputType="number" 28 android:gravity="center" 29 android:textSize="20sp"/> 30 <EditText 31 android:id="@+id/et_2" 32 android:layout_width="200dp" 33 android:layout_height="wrap_content" 34 android:hint="请输入一个数" 35 android:layout_marginLeft="100dp" 36 android:layout_marginRight="100dp" 37 android:inputType="number" 38 android:gravity="center" 39 android:textSize="20sp" /> 40 <LinearLayout 41 android:id="@+id/a_2" 42 android:layout_width="wrap_content" 43 android:layout_height="wrap_content" 44 android:orientation="horizontal" 45 android:layout_marginTop="20dp" 46 android:layout_marginRight="20dp" 47 android:layout_marginLeft="20dp"> 48 <Button 49 android:id="@+id/bt_1" 50 android:layout_width="wrap_content" 51 android:layout_height="wrap_content" 52 android:text="加(+)" 53 android:background="#F7BACE"/> 54 <Button 55 android:id="@+id/bt_2" 56 android:layout_width="wrap_content" 57 android:layout_height="wrap_content" 58 android:text="减(-)" 59 android:background="#F7BACE" /> 60 <Button 61 android:id="@+id/bt_3" 62 android:layout_width="wrap_content" 63 android:layout_height="wrap_content" 64 android:text="乘(*)" 65 android:background="#F7BACE"/> 66 <Button 67 android:id="@+id/bt_4" 68 android:layout_width="wrap_content" 69 android:layout_height="wrap_content" 70 android:text="除(/)" 71 android:background="#F7BACE"/> 72 </LinearLayout> 73 <TextView 74 android:id="@+id/tv_2" 75 android:layout_width="wrap_content" 76 android:layout_height="wrap_content" 77 android:text="结果=" 78 android:textSize="25sp" 79 android:textColor="#000000" 80 android:layout_marginLeft="150dp" 81 android:layout_marginRight="150dp" 82 android:layout_marginTop="50dp" 83 android:gravity="center"/> 84 85 86 </LinearLayout>
1 package com.example.Lwk3; 2 3 import androidx.appcompat.app.AppCompatActivity; 4 5 import android.content.Intent; 6 import android.os.Bundle; 7 import android.view.View; 8 import android.widget.EditText; 9 import android.widget.TextView; 10 11 public class MainActivity extends AppCompatActivity { 12 13 @Override 14 protected void onCreate(Bundle savedInstanceState) { 15 super.onCreate(savedInstanceState); 16 setContentView(R.layout.activity_main); 17 findViewById(R.id.bt_1).setOnClickListener(new View.OnClickListener() { 18 @Override 19 public void onClick(View view) { 20 String num1=((EditText)(findViewById(R.id.et_1))).getText().toString();//获取et_1上面的文本,并转成字符串 21 String num2=((EditText)(findViewById(R.id.et_2))).getText().toString();//获取et_2上面的文本,并转成字符串 22 23 int n1= Integer.parseInt(num1); 24 int n2= Integer.parseInt(num2); 25 int sum=n1+n2; 26 TextView tv_1=findViewById(R.id.tv_2);//获取TextView 控件 27 tv_1.setText("结果="+sum); 28 } 29 }); 30 findViewById(R.id.bt_2).setOnClickListener(new View.OnClickListener() { 31 @Override 32 public void onClick(View view) { 33 String num1=((EditText)(findViewById(R.id.et_1))).getText().toString(); 34 String num2=((EditText)(findViewById(R.id.et_2))).getText().toString(); 35 int n1=Integer.parseInt(num1); 36 int n2=Integer.parseInt(num2); 37 int sum=n1-n2; 38 TextView tv_1=findViewById(R.id.tv_2); 39 tv_1.setText("结果="+sum); 40 } 41 }); 42 findViewById(R.id.bt_3).setOnClickListener(new View.OnClickListener() { 43 @Override 44 public void onClick(View view) { 45 String num1=((EditText)(findViewById(R.id.et_1))).getText().toString(); 46 String num2=((EditText)(findViewById(R.id.et_2))).getText().toString(); 47 int n1=Integer.parseInt(num1); 48 int n2=Integer.parseInt(num2); 49 int sum=n1*n2; 50 TextView tv_1=findViewById(R.id.tv_2); 51 tv_1.setText("结果="+sum); 52 } 53 }); 54 findViewById(R.id.bt_4).setOnClickListener(new View.OnClickListener() { 55 @Override 56 public void onClick(View view) { 57 String num1=((EditText)(findViewById(R.id.et_1))).getText().toString(); 58 String num2=((EditText)(findViewById(R.id.et_2))).getText().toString(); 59 int n1=Integer.parseInt(num1); 60 int n2=Integer.parseInt(num2); 61 int sum=n1/n2; 62 TextView tv_1=findViewById(R.id.tv_2); 63 tv_1.setText("结果="+sum); 64 } 65 }); 66 } 67 }