考点：

1. Activity之间的跳转
   1. 显式意图
   2. 隐式意图
2. Activity中的数据传送
   1. Activity01.class传到Activity02.class
   2. 从Activity02.class回传到Activity01.class(数据回传)

一、Activity之间的跳转

Intent intent =new Intent(this , Activity02.class);
startActivity(intent);

//打开浏览器的例子
Button button = (Button) findViewById(R.id.main_btn);
button.setOnClickListener(new View.OnClickListener() {
    public void onClick(View v){
        Intent intent = new Intent();
        intent.setAction("andriod.intent.action.VIEW");
        intent.setData(Uri.parse("http//:www.baidu.com"));
        startActivity()
    }
})

二、Activity中的数据传送

1.从Activity01.class传到Activity02.class

Intent intent = new Intent(this ,Activity02.class);
intent.putExtra("extra_data" ,"Hello,Activity02!");
startActivity(intent);

Intent intent = getIntent();                        //通过getIntent()方法获得Intent对象
String data = intent.getStringExtra("extra_data");    //getIntExtra()...

3.5的一个例子

public class MainActivity extends AppCompatActivity{
    private EditText et_name;
    private EditText et_password;
    private Button btn;
    protected void onCreate(Bundle savedInstanceState/*保存的实例状态*/){
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        et_name = (EditText) findViewById(R.id.et_name);
        et_password = (EditText) findViewById(R.id.et_password);
        btn = (Button) findViewById(R.id.btn);
        btn.setOnClickListener(new View.OnClickListener(){
            public onClick(View v){
                passData();
            }
        })
    }
    public void passData(){
        Intent intent = new Intent(this ,ShowActivity.class);    //创建Intent对象
        intent.putExtra("name",et_name.getText().toString().trim());    //传递参数给Intent
        intent.putExtra("password",et_password.getText().toString().trim());
        startActivity(intent);
    }
}

public class ShowActivity extends AppCompatActivity{
    private TextView t_name;
    private TextView t_password;
    protected onCreate(Bundle savedInstanceState){
        super.onCreate(savedInstanceState);
        setContentView(R.layout.Activity_show);
        Intent intent = getIntent();
        String g_name = intent.getStringExtra("name");
        String g_password = intent.getStringExtra("password");
    }
}

2.//数据回传//从Activity02.class回传到Activity01.class

startActivityForResult(Intent intent ,int requestCode);//回传数据、启动第2个Activity；请求码用来判断数据来源
setResult(int resultCode ,Intent data); //回传处理结果,处理成功为1，失败为0；向第1个Activity中传递数据
onActivityResult(int requestCode ,int resultCode ,Intent data);//第1个Activity用来获得回传的数据

Intent intent = new intent(this ,Activity02.class);
startActivityForResult(intent,1);
    //protected的方法
protected void onActivityResult(int requestCode, int resultCode, Intent data){
    super.onActivityResult(requestCode, resultCode, data);
    if(requestCode == 1){
        if(resultCode == 1){
            String extra = data.getStringExtra("extra");
        }
    }
}

Intent intent = new Intent();
intent.putExtra("extra","Hello,Activity01!");
setResult(1,intent);