android studio数据回传例子

以下是一个Android Studio数据回传的例子：

1.在Activity A中，我们定义一个requestCode和一个Intent，然后使用startActivityForResult()方法启动Activity B：

public class ActivityA extends AppCompatActivity {
    private static final int REQUEST_CODE = 1;
    private Intent intent;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_a);

        intent = new Intent(ActivityA.this, ActivityB.class);
        startActivityForResult(intent, REQUEST_CODE);    }

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

        if (requestCode == REQUEST_CODE && resultCode == RESULT_OK) {
            String result = data.getStringExtra("result");
            Toast.makeText(ActivityA.this, result, Toast.LENGTH_SHORT).show();
        }
    }
}

2.在Activity B中，我们定义一个Intent，然后使用setResult()方法将数据回传给Activity A：

public class ActivityB extends AppCompatActivity {
    private Intent intent;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_b);

        intent = getIntent();
    }

    @Override
    public void onBackPressed() {
        String result = "Data returned from Activity B";
        intent.putExtra("result", result);
        setResult(RESULT_OK, intent);
        finish();
    }
}

在Activity B中，我们重写了onBackPressed()方法，当用户按下返回键时，我们将数据回传给Activity A，并关闭Activity B。