在Activity之间传递数据—获取Activity返回的数据

在获取返回值时要注意的是打开Activity的方式,用方法:startActivityForResult

接收时,重写方法:onActivityResult
在子Activity中,写数据用方法:setResult

MainActivity代码:

 private TextView tv;
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);

findViewById(R.id.btnStart).setOnClickListener(new View.OnClickListener() {
    @Override
    public void onClick(View view) {
        Intent i=new Intent(MainActivity.this,OthereActivity.class);
       startActivityForResult(i,0); //用这种方式启动接收 ,第二个为请求码
    }
});
    }

    @Override
    protected void onActivityResult(int requestCode, int resultCode, Intent data) {
        super.onActivityResult(requestCode, resultCode, data);

        tv=(TextView)findViewById(R.id.textView);

        tv.setText("另一个Activity返回的是:"+data.getStringExtra("data"));
    }

OtherActivity代码:
private EditText editText;
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_othere);

       editText= (EditText) findViewById(R.id.editText);
        findViewById(R.id.btnBack).setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View view) {
                Intent intent=new Intent();
                intent.putExtra("data",editText.getText().toString());
                setResult(1,intent); //写返回值
                finish();//结束掉当前Activity
            }
        });
    }