Android学习手记(3) Activity间传递数据

1、 简单数据传递

　　建立两个Activity，名称分别为MainActivity和TheAty，在MainActivity中新建一个Button，id为btnStartAty。在TheAty中新建一个TextView，id为tv。分别加入如下代码：

MainActivity.java

public class MainActivity extends AppCompatActivity {    @Override    protected void onCreate(Bundle savedInstanceState) {        super.onCreate(savedInstanceState);        setContentView(R.layout.activity_main);        Button button = (Button)findViewById(R.id.btnStartAty);        button.setOnClickListener(new View.OnClickListener() {            @Override            public void onClick(View v) {                Intent i = new Intent();                i.setClass(MainActivity.this, TheAty.class);                i.putExtra("data", "hello android");                startActivity(i);            }        });    }}

TheAty.java

public class TheAty extends AppCompatActivity {    private TextView textv;    @Override    protected void onCreate(Bundle savedInstanceState) {        super.onCreate(savedInstanceState);        setContentView(R.layout.activity_the_aty);        Intent i = getIntent();        textv = (TextView)findViewById(R.id.tv);        textv.setText(i.getStringExtra("data"));    }}

　　其中，Intent i 的作用是作为绑定两个Activity的中介，然后进行string的传递。使用putExtra()的getStringExtra()函数对来实现简单值的传递。

2、 使用Bundle传递数据

MainActivity.java

public class MainActivity extends AppCompatActivity {    private EditText myText;    @Override    protected void onCreate(Bundle savedInstanceState) {        super.onCreate(savedInstanceState);        setContentView(R.layout.activity_main);        myText = (EditText)findViewById(R.id.editText);        Button button = (Button) findViewById(R.id.btnOK);        button.setOnClickListener(new View.OnClickListener() {            @Override            public void onClick(View v) {                String str = myText.getText().toString();                Intent i = new Intent(MainActivity.this, TheAty.class);                Bundle bundle = new Bundle();                bundle.putString("message", str);                i.putExtras(bundle);                startActivity(i);            }        });    }}

TheAty.java

public class TheAty extends AppCompatActivity {    @Override    protected void onCreate(Bundle savedInstanceState) {        super.onCreate(savedInstanceState);        setContentView(R.layout.activity_the_aty);        Bundle bundle = this.getIntent().getExtras();        String mesg = bundle.getString("message");        TextView myText = (TextView) findViewById(R.id.tv);        myText.setText(mesg);    }}