1 import android.app.Activity; 2 import android.os.Bundle; 3 import android.util.Log; 4  5 public class LifeCycleActivity extends Activity{ 6      7     @Override 8     protected void onCreate(Bundle savedInstanceState) { 9         super.onCreate(savedInstanceState);10         Log.e(this.getClass().getName(), "onCreate");11     }12     13     @Override14     protected void onStart() {15         super.onStart();16         Log.e(this.getClass().getName(), "onStart");17     }18     19     @Override20     protected void onResume() {21         super.onResume();22         Log.e(this.getClass().getName(), "onResume");23     }24     25     @Override26     protected void onPause() {27         super.onPause();28         Log.e(this.getClass().getName(), "onPause");29     }30     31     @Override32     protected void onStop() {33         super.onStop();34         Log.e(this.getClass().getName(), "onStop");35     }36     37     @Override38     protected void onDestroy() {39         super.onDestroy();40         Log.e(this.getClass().getName(), "onDestroy");41     }42 }

  1 import android.content.Intent;  2 import android.os.Bundle;  3 import android.util.Log;  4 import android.view.View;  5 import android.view.View.OnClickListener;  6 import android.widget.Button;  7 import android.widget.Toast;  8   9 public class MainActivity extends LifeCycleActivity { 10  11     public static final String TAG = "MainActivity"; 12     Button button,buttonNext,buttonMsg,buttonSex,buttonHeight,buttonBack; 13      14     public static final int SEX_SELECT = 1; 15     public static final int HEIGHT_SELECT = 2; 16      17     @Override 18     protected void onCreate(Bundle savedInstanceState) { 19         super.onCreate(savedInstanceState); 20         setContentView(R.layout.activity_main); 21          22         //自己点击自己 23         button = (Button) findViewById(R.id.main_btn); 24         button.setOnClickListener(new OnClickListener() { 25             @Override 26             public void onClick(View v) { 27                 //定义一个意图,启动FirstActivity 28                 Intent intent = new Intent(MainActivity.this, MainActivity.class); 29                 Toast.makeText(MainActivity.this, "你点击了自己", Toast.LENGTH_SHORT).show(); 30                 startActivity(intent); 31             } 32         }); 33          34         //启动下一个界面，不带参数 35         buttonNext = (Button) findViewById(R.id.main_btn_next); 36         buttonNext.setOnClickListener(new OnClickListener() { 37             @Override 38             public void onClick(View v) { 39                 //定义一个意图,启动FirstActivity 40                 Intent intent = new Intent(MainActivity.this, FirstActivity.class); 41                 startActivity(intent); 42             } 43         }); 44          45         //启动下一个界面，并传递参数给下一个界面，比如发送一个句话 46         buttonMsg = (Button)findViewById(R.id.main_btn_msg); 47         buttonMsg.setOnClickListener(new OnClickListener() { 48             @Override 49             public void onClick(View v) { 50                 Intent intent = new Intent(MainActivity.this, SecondActivity.class); 51                 intent.putExtra("msg", "我要送你一句话"); 52                 startActivity(intent); 53                  54             } 55         }); 56          57          58         //启动下一个界面，选择性别，并将选择结果返回显示在MainActivity中 59         buttonSex = (Button)findViewById(R.id.main_sex); 60         buttonSex.setOnClickListener(new OnClickListener() { 61             @Override 62             public void onClick(View v) { 63                 Intent intent = new Intent(MainActivity.this, ThirdActivity.class); 64                  65                 startActivityForResult(intent, SEX_SELECT); 66             } 67         }); 68          69         //启动下一个界面，输入身高，并将结果返回显示在MainActivity中 70         buttonHeight = (Button) findViewById(R.id.main_height); 71         buttonHeight.setOnClickListener(new OnClickListener() { 72             @Override 73             public void onClick(View v) { 74                 Intent intent = new Intent(MainActivity.this, FourActivity.class); 75                 startActivityForResult(intent, HEIGHT_SELECT); 76             } 77         }); 78          79         //退出App 80         buttonBack = (Button) findViewById(R.id.main_btn_back); 81         buttonBack.setOnClickListener(new OnClickListener() { 82             @Override 83             public void onClick(View v) { 84                 //主活动点击返回直接退出程序 85                 finish(); 86             } 87         }); 88     } 89      90      91     @Override 92     protected void onActivityResult(int requestCode, int resultCode, Intent data) { 93          94         switch (requestCode) { 95         case SEX_SELECT: 96             String sex; 97             if(resultCode == ThirdActivity.MAN_CODE){ 98                 sex = data.getStringExtra("sex_result"); 99                 Log.e(TAG, "sex = "+sex);//null100                 buttonSex.setText("选择了"+sex);101             }else {102                 sex = data.getStringExtra("sex_result");103                 buttonSex.setText("选择了"+sex);104             }105             break;106         case HEIGHT_SELECT:107             int height;108             if(resultCode == FourActivity.SUBMIT){109                 //必须给默认值110                 height = data.getIntExtra("height", -1);111                 buttonHeight.setText(height+"cm");112             }113             break;114         default:115         }116     }117     118 }

 1 import android.os.Bundle; 2 import android.view.View; 3 import android.view.View.OnClickListener; 4 import android.widget.Button; 5  6 public class FirstActivity extends LifeCycleActivity{ 7  8         @Override 9         protected void onCreate(Bundle savedInstanceState) {10             super.onCreate(savedInstanceState);11             setContentView(R.layout.activity_first);12             13             //关闭这个界面，会回到上一个界面14             Button buttonBack = (Button)findViewById(R.id.first_btn_back);15             buttonBack.setOnClickListener(new OnClickListener() {16                 @Override17                 public void onClick(View v) {18                     //返回到上一个界面19                     finish();20                 }21             });22             23         }               26 }

 1 import android.content.Intent; 2 import android.os.Bundle; 3 import android.view.View; 4 import android.view.View.OnClickListener; 5 import android.widget.Button; 6 import android.widget.TextView; 7  8 public class SecondActivity extends LifeCycleActivity { 9 10     TextView tv;11     12     @Override13     protected void onCreate(Bundle savedInstanceState) {14         super.onCreate(savedInstanceState);15         setContentView(R.layout.activity_second);16         tv = (TextView) findViewById(R.id.text);17         18         //获取意图19         Intent intent = getIntent();20         //通过键key获取数据值21         String data = http://www.mamicode.com/intent.getStringExtra("msg");22         23         //显示接收到的数据24         tv.setText("收到:"+data);25         26         Button buttonBack = (Button)findViewById(R.id.second_btn_back);27         buttonBack.setOnClickListener(new OnClickListener() {28             @Override29             public void onClick(View v) {30                 finish();31             }32         });33     }34     35     36 }

 1 import android.content.Intent; 2 import android.os.Bundle; 3 import android.view.View; 4 import android.view.View.OnClickListener; 5 import android.widget.Button; 6  7 public class ThirdActivity extends LifeCycleActivity implements OnClickListener{ 8     public static final int MAN_CODE = 1; 9     public static final int WOMAN_CODE = 2;10     11     Button man,woman;12     Intent intent;13     @Override14     protected void onCreate(Bundle savedInstanceState) {15         super.onCreate(savedInstanceState);16         setContentView(R.layout.activity_third);17         18         19         man = (Button) findViewById(R.id.man);20         man.setOnClickListener(this);21         22         woman = (Button) findViewById(R.id.woman);23         woman.setOnClickListener(this);24         25     }26     27     @Override28     public void onClick(View v) {29         intent = new Intent();30         switch (v.getId()) {31         case R.id.man:32             intent.putExtra("sex_result", "男");33             34             setResult(MAN_CODE, intent);35             finish();36             break;37         case R.id.woman:38             intent.putExtra("sex_result", "女");39             setResult(WOMAN_CODE, intent);40             finish();41             break;42         default:43         }44     }45 }

 1 import android.content.Intent; 2 import android.os.Bundle; 3 import android.view.View; 4 import android.view.View.OnClickListener; 5 import android.widget.Button; 6 import android.widget.EditText; 7  8 public class FourActivity extends LifeCycleActivity implements OnClickListener{ 9     Button submit,cancel;10     EditText et;11     @Override12     protected void onCreate(Bundle savedInstanceState) {13         super.onCreate(savedInstanceState);14         setContentView(R.layout.activity_four);15         16         submit = (Button) findViewById(R.id.four_submit);17         cancel = (Button) findViewById(R.id.four_cancel);18         et = (EditText) findViewById(R.id.four_edit);19         20         submit.setOnClickListener(this);21         cancel.setOnClickListener(this);22     }23     24     public static final int SUBMIT = 1;25     public static final int CANCEL = 2;26     @Override27     public void onClick(View v) {28         Intent intent = new Intent();29         switch (v.getId()) {30         case R.id.four_submit:31             int height = Integer.parseInt(et.getText().toString());32             intent.putExtra("height", height);33             setResult(SUBMIT, intent);34             finish();35             break;36         case R.id.four_cancel:37             setResult(CANCEL);38             finish();39             break;40         default:41             break;42         }43         44     }45 }