如何将字符串从一个活动发送到另一个活动？

// 发送活动
Intent intent = new Intent(this, SecondActivity.class);
intent.putExtra("key_string", "Hello, Second Activity!");
startActivity(intent);

// 接收活动
@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_second);

    Intent intent = getIntent();
    String receivedString = intent.getStringExtra("key_string");
    TextView textView = findViewById(R.id.textView);
    textView.setText(receivedString);
}

// 确保键值对一致
intent.putExtra("key_string", "Hello, Second Activity!");
String receivedString = intent.getStringExtra("key_string");

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

    TextView textView = findViewById(R.id.textView);
    if (textView != null) {
        String receivedString = getIntent().getStringExtra("key_string");
        textView.setText(receivedString);
    }
}