正确代码 = =

1.Testactivity1.java

  1 package com.hanqi.myapplication;
  2 
  3 import android.app.Activity;
  4 import android.content.Intent;
  5 import android.os.Bundle;
  6 import android.util.Log;
  7 import android.view.View;
  8 import android.widget.EditText;
  9 import android.widget.Toast;
 10 
 11 //1.继承Activity
 12 /**
 13  * Created by lenovo on 2016/4/22.
 14  */
 15 public class TestActivity1 extends Activity {
 16 
 17     //成员变量
 18     EditText et1;
 19     EditText et2;
 20     EditText et3;
 21     //2.重写onCreate(),关联Layout文件
 22     //onCreate()是一个回调方法：在满足特定条件下自动调用的方法；方法名一般on开头
 23 
 24     @Override
 25     protected void onCreate(Bundle savedInstanceState) {
 26         super.onCreate(savedInstanceState);
 27 
 28         //关联
 29         setContentView(R.layout.message_relativelayout);
 30         //初始化工作
 31         //获取Layout文件中定义的组件
 32 
 33         et1=(EditText)findViewById(R.id.et1);
 34         et2=(EditText)findViewById(R.id.et2);
 35         et3=(EditText)findViewById(R.id.et3);
 36         Log.e("TAG","onCreat()被调用");
 37 
 38         //得到意图
 39         Intent intent = getIntent();
 40         String strname = intent.getStringExtra("name");
 41         String strname1 = intent.getStringExtra("name1");
 42         //intent.getExtras();
 43         Log.e("TAG","意图传递的数据="+strname);
 44         Log.e("TAG","意图传递的数据1="+strname1);
 45 //        if(savedInstanceState!=null&&!savedInstanceState.isEmpty())
 46 //        {
 47 //        et1.setText(savedInstanceState.getString("et1")+"恢复之后的");
 48 //        et2.setText(savedInstanceState.getString("et2"));
 49 //        et3.setText(savedInstanceState.getString("et3"));
 50 //        }
 51     }
 52 
 53     //保存状态
 54     @Override
 55     protected void onSaveInstanceState(Bundle outState) {
 56         super.onSaveInstanceState(outState);
 57         Log.e("TAG", "保存应用状态");
 58 
 59         outState.putString("et1", et1.getText().toString());
 60         outState.putString("et1",et2.getText().toString());
 61         outState.putString("et1",et3.getText().toString());
 62     }
 63 
 64     //恢复状态
 65     @Override
 66     protected void onRestoreInstanceState(Bundle savedInstanceState) {
 67         super.onRestoreInstanceState(savedInstanceState);
 68         Log.e("TAG", "恢复应用状态");
 69 
 70         et1.setText(savedInstanceState.getString("et1"));
 71         et2.setText(savedInstanceState.getString("et2"));
 72         et3.setText(savedInstanceState.getString("et3"));
 73 
 74     }
 75 
 76     //启动
 77     @Override
 78     protected void onStart() {
 79         super.onStart();
 80         Log.e("TAG","onStart()被调用");
 81     }
 82     //重启
 83     @Override
 84     protected void onRestart() {
 85         super.onRestart();
 86         Log.e("TAG", "onRestart()被调用");
 87     }
 88     //继续
 89     @Override
 90     protected void onResume() {
 91         super.onResume();
 92         Log.e("TAG", "onResume()被调用");
 93     }
 94     //暂停
 95     @Override
 96     protected void onPause() {
 97         super.onPause();
 98         Log.e("TAG", "onPause()被调用");
 99     }
100     //停止
101     @Override
102     protected void onStop() {
103         super.onStop();
104         Log.e("TAG", "onStop()被调用");
105     }
106     //销毁
107     @Override
108     protected void onDestroy() {
109         super.onDestroy();
110         Log.e("TAG", "onDestroy()被调用");
111     }
112     //点击事件方法
113     public void bt_OnClick(View v)
114     {
115         //显示提示信息
116         //方法链
117         Toast.makeText(TestActivity1.this, "消息发送成功", Toast.LENGTH_SHORT).show();
118     }
119     public void close_OnClick(View v)
120     {
121         //关闭应用
122         finish();
123     }
124 }

2.MainActivity.java

 1 package com.hanqi.myapplication;
 2 
 3 import android.content.ComponentName;
 4 import android.content.Intent;
 5 import android.net.Uri;
 6 import android.os.Bundle;
 7 import android.support.v7.app.AppCompatActivity;
 8 import android.util.Log;
 9 import android.view.View;
10 import android.widget.Button;
11 
12 public class MainActivity extends AppCompatActivity {
13 
14     //回调方法 （on开头的方法都是）
15     //在创建时自动调用
16     @Override
17     protected void onCreate(Bundle savedInstanceState) {
18         //调用父类的回调方法
19         super.onCreate(savedInstanceState);
20         //设置内容视图文件
21         //建立Activity和Layout文件之间的关联
22         setContentView(R.layout.test_linearlayout);
23         //1.获得这个组件
24         Button bt2 =  (Button)findViewById(R.id.button2);
25         //2.操作这个组件
26         // bt2.setText("新按钮");
27         //日志输出
28         System.out.print("日志输出=应用开始运行");
29         Log.v("HANQI", "Verbose级别的日志信息");
30         Log.d("HANQI", "Debug级别的日志信息");
31         Log.i("HANQI", "Info级别的日志信息");
32         Log.w("HANQI", "Warning级别的日志信息");
33         Log.e("HANQI", "Error级别的日志信息");
34     }
35     public void login_onClick(View v)
36     {
37         //打开新的Activity
38         //1.创建意图  显式意图
39         Intent intent = new Intent();
40         //定义显式意图
41         ComponentName componentName = new ComponentName(this,TestActivity1.class);
42         intent.setComponent(componentName);
43         intent.putExtra("name", "意图传递的值");
44         intent.putExtra("name1", "意图传递的值1");
45 
46         //2.发起意图
47         startActivity(intent);
48     }
49     public void bt2_onClick(View v)
50     {
51         //发起隐式意图
52         //打开拨打电话的界面
53         //系统已经预先定义了常用功能的Action的字符串常量
54         Intent intent2 = new Intent(Intent.ACTION_CALL);
55         //intent2.setAction(Intent.ACTION_DIAL);
56 
57         //构造Uri
58         Uri uri = Uri.parse("tel:110");
59 
60         //intent2.addCategory("");
61 
62         //设置data
63         intent2.setData(uri);
64 
65         //intent2.setType("");
66         //intent2.setDataAndType(uri,"");
67 
68         try
69         {
70             startActivity(intent2);
71         }
72         catch (Exception e){
73             e.printStackTrace();
74         }
75     }
76 
77     public void bt3_onClick(View v)
78     {
79         //返回桌面
80         Intent intent3 = new Intent(Intent.ACTION_MAIN);
81 
82         intent3.addCategory(Intent.CATEGORY_HOME);
83 
84         startActivity(intent3);
85     }
86     public void bt4_onClick(View v)
87     {
88         //定义隐式意图
89         Intent intent4 = new Intent("com.hanqi.action.test1");
90         //如果不主动添加Category，默认给Category加上"android.intent.category.DEFAULT"
91         //主动添加Category
92         intent4.addCategory("com.hanqi.category.test1");
93         startActivity(intent4);
94     }
95 }

3.Android Mani fest.xml

 1 package com.hanqi.myapplication;
 2 
 3 import android.content.ComponentName;
 4 import android.content.Intent;
 5 import android.net.Uri;
 6 import android.os.Bundle;
 7 import android.support.v7.app.AppCompatActivity;
 8 import android.util.Log;
 9 import android.view.View;
10 import android.widget.Button;
11 
12 public class MainActivity extends AppCompatActivity {
13 
14     //回调方法 （on开头的方法都是）
15     //在创建时自动调用
16     @Override
17     protected void onCreate(Bundle savedInstanceState) {
18         //调用父类的回调方法
19         super.onCreate(savedInstanceState);
20         //设置内容视图文件
21         //建立Activity和Layout文件之间的关联
22         setContentView(R.layout.test_linearlayout);
23         //1.获得这个组件
24         Button bt2 =  (Button)findViewById(R.id.button2);
25         //2.操作这个组件
26         // bt2.setText("新按钮");
27         //日志输出
28         System.out.print("日志输出=应用开始运行");
29         Log.v("HANQI", "Verbose级别的日志信息");
30         Log.d("HANQI", "Debug级别的日志信息");
31         Log.i("HANQI", "Info级别的日志信息");
32         Log.w("HANQI", "Warning级别的日志信息");
33         Log.e("HANQI", "Error级别的日志信息");
34     }
35     public void login_onClick(View v)
36     {
37         //打开新的Activity
38         //1.创建意图  显式意图
39         Intent intent = new Intent();
40         //定义显式意图
41         ComponentName componentName = new ComponentName(this,TestActivity1.class);
42         intent.setComponent(componentName);
43         intent.putExtra("name", "意图传递的值");
44         intent.putExtra("name1", "意图传递的值1");
45 
46         //2.发起意图
47         startActivity(intent);
48     }
49     public void bt2_onClick(View v)
50     {
51         //发起隐式意图
52         //打开拨打电话的界面
53         //系统已经预先定义了常用功能的Action的字符串常量
54         Intent intent2 = new Intent(Intent.ACTION_CALL);
55         //intent2.setAction(Intent.ACTION_DIAL);
56 
57         //构造Uri
58         Uri uri = Uri.parse("tel:110");
59 
60         //intent2.addCategory("");
61 
62         //设置data
63         intent2.setData(uri);
64 
65         //intent2.setType("");
66         //intent2.setDataAndType(uri,"");
67 
68         try
69         {
70             startActivity(intent2);
71         }
72         catch (Exception e){
73             e.printStackTrace();
74         }
75     }
76 
77     public void bt3_onClick(View v)
78     {
79         //返回桌面
80         Intent intent3 = new Intent(Intent.ACTION_MAIN);
81 
82         intent3.addCategory(Intent.CATEGORY_HOME);
83 
84         startActivity(intent3);
85     }
86     public void bt4_onClick(View v)
87     {
88         //定义隐式意图
89         Intent intent4 = new Intent("com.hanqi.action.test1");
90         //如果不主动添加Category，默认给Category加上"android.intent.category.DEFAULT"
91         //主动添加Category
92         intent4.addCategory("com.hanqi.category.test1");
93         startActivity(intent4);
94     }
95 }

4.Test linearlayout.xml

 1 <?xml version="1.0" encoding="utf-8"?>
 2 <LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
 3     android:orientation="vertical"
 4     android:layout_width="match_parent"
 5     android:layout_height="match_parent"
 6     android:padding="10dp">
 7 
 8     <LinearLayout
 9         android:layout_width="match_parent"
10         android:layout_height="wrap_content">
11         <TextView
12             android:layout_width="wrap_content"
13             android:layout_height="wrap_content"
14             android:text="用户名："/>
15         <EditText
16             android:layout_width="match_parent"
17             android:layout_height="wrap_content"
18             android:hint="请输入用户名"/>
19     </LinearLayout>
20     <LinearLayout
21         android:layout_width="match_parent"
22         android:layout_height="wrap_content">
23         <TextView
24             android:layout_width="wrap_content"
25             android:layout_height="wrap_content"
26             android:text="密码："/>
27         <EditText
28             android:layout_width="match_parent"
29             android:layout_height="wrap_content"
30             android:hint="请输入密码"
31             android:inputType="textPassword"
32             android:maxLength="6"/>
33     </LinearLayout>
34 
35     <LinearLayout
36         android:layout_width="match_parent"
37         android:layout_height="wrap_content">
38         <Button
39             android:layout_width="0dp"
40             android:layout_height="wrap_content"
41             android:text="显式意图"
42             android:id="@+id/button"
43             android:layout_weight="1"
44             android:onClick="login_onClick"/>
45 
46         <Button
47             android:layout_width="0dp"
48             android:layout_height="wrap_content"
49             android:text="隐式意图"
50             android:id="@+id/button3"
51             android:layout_weight="1"
52             android:onClick="bt2_onClick"/>
53         <Button
54             android:layout_width="0dp"
55             android:layout_height="wrap_content"
56             android:text="返回桌面"
57             android:id="@+id/button4"
58             android:layout_weight="1"
59             android:onClick="bt3_onClick"/>
60 
61         <Button
62             android:layout_width="wrap_content"
63             android:layout_height="wrap_content"
64             android:text="New Button"
65             android:id="@+id/button2"
66             android:layout_gravity="center"
67             android:textSize="20sp"
68             android:textColor="@color/colorPrimary"
69             android:visibility="gone"/>
70     </LinearLayout>
71     <Button
72         android:layout_width="match_parent"
73         android:layout_height="wrap_content"
74         android:text="隐式意图打开Activity"
75         android:onClick="bt4_onClick"/>
76 </LinearLayout>

5.TestAcivity2.java

  1 package com.hanqi.myapplication;
  2 
  3 import android.app.Activity;
  4 import android.content.Intent;
  5 import android.os.Bundle;
  6 import android.util.Log;
  7 import android.view.View;
  8 import android.widget.EditText;
  9 import android.widget.Toast;
 10 
 11 //1.继承Activity
 12 
 13 /**
 14  * Created by lenovo on 2016/4/22.
 15  */
 16 public class TestActivity2 extends Activity{
 17 
 18     //成员变量
 19     EditText et1;
 20     EditText et2;
 21     EditText et3;
 22     //2.重写onCreate(),关联Layout文件
 23     //onCreate()是一个回调方法：在满足特定条件下自动调用的方法；方法名一般on开头
 24 
 25     @Override
 26     protected void onCreate(Bundle savedInstanceState) {
 27         super.onCreate(savedInstanceState);
 28 
 29         //关联
 30         setContentView(R.layout.message_relativelayout);
 31         //初始化工作
 32         //获取Layout文件中定义的组件
 33 
 34         et1=(EditText)findViewById(R.id.et1);
 35         et2=(EditText)findViewById(R.id.et2);
 36         et3=(EditText)findViewById(R.id.et3);
 37         Log.e("TAG","onCreat()被调用");
 38 
 39         //得到意图
 40         Intent intent = getIntent();
 41         String strname = intent.getStringExtra("name");
 42         String strname1 = intent.getStringExtra("name1");
 43         //intent.getExtras();
 44         Log.e("TAG","意图传递的数据="+strname);
 45         Log.e("TAG","意图传递的数据1="+strname1);
 46 //        if(savedInstanceState!=null&&!savedInstanceState.isEmpty())
 47 //        {
 48 //        et1.setText(savedInstanceState.getString("et1")+"恢复之后的");
 49 //        et2.setText(savedInstanceState.getString("et2"));
 50 //        et3.setText(savedInstanceState.getString("et3"));
 51 //        }
 52     }
 53 
 54     //保存状态
 55     @Override
 56     protected void onSaveInstanceState(Bundle outState) {
 57         super.onSaveInstanceState(outState);
 58         Log.e("TAG", "保存应用状态");
 59 
 60         outState.putString("et1", et1.getText().toString());
 61         outState.putString("et1",et2.getText().toString());
 62         outState.putString("et1",et3.getText().toString());
 63     }
 64 
 65     //恢复状态
 66     @Override
 67     protected void onRestoreInstanceState(Bundle savedInstanceState) {
 68         super.onRestoreInstanceState(savedInstanceState);
 69         Log.e("TAG", "恢复应用状态");
 70 
 71         et1.setText(savedInstanceState.getString("et1")+"恢复之后的");
 72         et2.setText(savedInstanceState.getString("et2"));
 73         et3.setText(savedInstanceState.getString("et3"));
 74 
 75     }
 76 
 77     //启动
 78     @Override
 79     protected void onStart() {
 80         super.onStart();
 81         Log.e("TAG","onStart()被调用");
 82     }
 83     //重启
 84     @Override
 85     protected void onRestart() {
 86         super.onRestart();
 87         Log.e("TAG", "onRestart()被调用");
 88     }
 89     //继续
 90     @Override
 91     protected void onResume() {
 92         super.onResume();
 93         Log.e("TAG", "onResume()被调用");
 94     }
 95     //暂停
 96     @Override
 97     protected void onPause() {
 98         super.onPause();
 99         Log.e("TAG", "onPause()被调用");
100     }
101     //停止
102     @Override
103     protected void onStop() {
104         super.onStop();
105         Log.e("TAG", "onStop()被调用");
106     }
107     //销毁
108     @Override
109     protected void onDestroy() {
110         super.onDestroy();
111         Log.e("TAG", "onDestroy()被调用");
112     }
113     //点击事件方法
114     public void bt_OnClick(View v)
115     {
116         //显示提示信息
117         //方法链
118         Toast.makeText(TestActivity2.this, "消息发送成功", Toast.LENGTH_SHORT).show();
119     }
120     public void close_OnClick(View v)
121     {
122         //关闭应用
123         finish();
124     }
125 }
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原文地址：https://www.cnblogs.com/TENOKAWA/p/5434797.html