第一个安卓程序，传递数据

public class MainActivity extends Activity {
    private Button btn1=null;
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);//加载布局文件
        btn1=(Button)findViewById(R.id.button1);
        btn1.setOnClickListener(new View.OnClickListener() {
            
            @Override
            public void onClick(View v) {
                User user=new User("zhangsan", "bj", 23);
                //将对象转换成字符串
                String base64=null;
                                //序列化对象
                ByteArrayOutputStream byteArrayOutputStream=new ByteArrayOutputStream();
                try {
                    ObjectOutputStream objectOutputStream=new ObjectOutputStream(byteArrayOutputStream);
                    objectOutputStream.writeObject(user);
                    base64=Base64.encodeToString(byteArrayOutputStream.toByteArray(), Base64.DEFAULT);
                    objectOutputStream.close();
                    
                } catch (Exception e) {
                    // TODO: handle exception
                }
                
                //数据放入剪切板
                android.content.ClipboardManager clipboardManager=(android.content.ClipboardManager)getSystemService(Context.CLIPBOARD_SERVICE);
                clipboardManager.setText(base64);
                Intent intent=new Intent(MainActivity.this,SecondActivity.class);
                startActivity(intent);
                }

        });
    }
}        

转下个activity

public class SecondActivity extends Activity {
    private TextView textView;
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.firstr);
        textView =(TextView)findViewById(R.id.mss);
        //获取剪切板的数据
        ClipboardManager clipboardManager=(ClipboardManager)getSystemService(Context.CLIPBOARD_SERVICE);
        String message=clipboardManager.getText().toString();
        byte[] buffer=Base64.decode(message, Base64.DEFAULT);
        ByteArrayInputStream byteArrayInputStream=new ByteArrayInputStream(buffer);
        try{
        ObjectInputStream objectInputStream=new ObjectInputStream(byteArrayInputStream);
        User user=(User)objectInputStream.readObject();
        textView.setText(user.toString());
        }catch(Exception e){
            e.printStackTrace();
        }
        
        
        
        
    }
    
}

2.通过全局变量传递数据

定义全局变量

public class AllApplication extends Application {
    private String username;
    
    
    public String getUsername() {
        return username;
    }


    public void setUsername(String username) {
        this.username = username;
    }


    @Override
    public void onCreate() {
        super.onCreate();
        setUsername("zhangsanas");
    }
}

在清单表中加入全局类名称

 <application
        android:name=".AllApplication"
        android:allowBackup="true"
        android:icon="@drawable/ic_launcher"
        android:label="@string/app_name"
        android:theme="@style/AppTheme" >

主activity

public class Main extends Activity {
    private Button btn1=null;
    private AllApplication all;
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.main);
        btn1=(Button)findViewById(R.id.btn);
        btn1.setOnClickListener(new View.OnClickListener() {
            
            @Override
            public void onClick(View v) {
                all=(AllApplication)getApplication();
                all.setUsername("wangwu");
                Intent intent=new Intent(Main.this,Second.class);
                startActivity(intent);
                
            }
        });
    }
}

转向下个

public class Second extends Activity {
    private AllApplication allApplication;
    private TextView textView;
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        // TODO Auto-generated method stub
        super.onCreate(savedInstanceState);
        setContentView(R.layout.second);
        
        textView=(TextView)findViewById(R.id.mess);
        allApplication=(AllApplication)getApplication();
        textView.setText(allApplication.getUsername());

    }
    
}

带返回参数

public class Main extends Activity {
    private Button btn1=null;
    //定义一个请求的标志量
    private static final int REQUEST_CODE=1;
    private EditText one,two,result;
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.main);
        one=(EditText)findViewById(R.id.one);
        two=(EditText)findViewById(R.id.two);
        result=(EditText)findViewById(R.id.result);
        
        btn1=(Button)findViewById(R.id.btn);
        btn1.setOnClickListener(new View.OnClickListener() {
            
            @Override
            public void onClick(View v) {
                Intent intent=new Intent();
                intent.setClass(Main.this, Second.class);
                intent.putExtra("a", one.getText().toString());
                intent.putExtra("b", two.getText().toString());
                startActivityForResult(intent, REQUEST_CODE);            
                
            }
        });
    }
    @Override
    protected void onActivityResult(int requestCode, int resultCode, Intent data) {
        if(resultCode==2){
            if(requestCode==REQUEST_CODE){
                result.setText(data.getStringExtra("three"));
            }
        }
    }
}

public class Second extends Activity {
    private EditText editText;
    private TextView teView;
    private Button bt;
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        // TODO Auto-generated method stub
        super.onCreate(savedInstanceState);
        setContentView(R.layout.second);
        bt=(Button)findViewById(R.id.rebtn);
        teView=(TextView)findViewById(R.id.mess);
        editText=(EditText)findViewById(R.id.three);
        Intent intent=getIntent();
        String a=intent.getStringExtra("a");
        String b=intent.getStringExtra("b");
        teView.setText(a+" + "+b+" = ?");
        bt.setOnClickListener(new View.OnClickListener() {
            
            @Override
            public void onClick(View v) {
                Intent in=new Intent();
                in.putExtra("three",editText.getText().toString());
                setResult(2, in);
                finish();
                
            }
        });
        
        

    }
    
}