Android 开发笔记___Intent的使用

public class ActRequestActivity extends AppCompatActivity implements OnClickListener {

    private EditText et_request;
    private TextView tv_request;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_act_request);
        findViewById(R.id.btn_act_request).setOnClickListener(this);
        et_request = (EditText) findViewById(R.id.et_request);
        tv_request = (TextView) findViewById(R.id.tv_request);
    }

    @Override
    public void onClick(View v) {
        if (v.getId() == R.id.btn_act_request) {
            Intent intent = new Intent();
            intent.setClass(this, ActResponseActivity.class);
            intent.putExtra("request_time", DateUtil.getNowTime());
            intent.putExtra("request_content", et_request.getText().toString());
            startActivityForResult(intent, 0);
        }
    }

    @Override
    protected void onActivityResult(int requestCode, int resultCode, Intent data) {
        if (data != null) {
            String response_time = data.getStringExtra("response_time");
            String response_content = data.getStringExtra("response_content");
            String desc = String.format("收到返回消息：
应答时间为%s
应答内容为%s",
                    response_time, response_content);
            tv_request.setText(desc);
        }
    }

}

public class ActResponseActivity extends AppCompatActivity implements OnClickListener {

    private EditText et_response;
    private TextView tv_response;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_act_response);
        findViewById(R.id.btn_act_response).setOnClickListener(this);
        et_response = (EditText) findViewById(R.id.et_response);
        tv_response = (TextView) findViewById(R.id.tv_response);
        
        Bundle bundle = getIntent().getExtras();
        String request_time = bundle.getString("request_time");
        String request_content = bundle.getString("request_content");
        String desc = String.format("收到请求消息：
请求时间为%s
请求内容为%s",
                request_time, request_content);
        tv_response.setText(desc);
    }

    @Override
    public void onClick(View v) {
        if (v.getId() == R.id.btn_act_response) {
            Intent intent = new Intent();
            Bundle bundle = new Bundle();
            bundle.putString("response_time", DateUtil.getNowTime());
            bundle.putString("response_content", et_response.getText().toString());
            intent.putExtras(bundle);
            setResult(Activity.RESULT_OK, intent);
            finish();
        }
    }

}