Question

我有AddMembers.class活动和MembersFragment.class片段。我一直在尝试将数据从AddMembers发送到MembersFragment，因为通过日志记录，我确认使用setArguments（）方法正确设置了数据，但是在检索数据时却得到了空值。

所以谁能告诉我为什么我在片段中调用getArguments（）方法时会得到空值。

谢谢！

这是我的AddMembers.class src代码：

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

    Intent intent = getIntent();

    final String members_name = intent.getStringExtra("tripName");

    TextView membersTextView = findViewById(R.id.membersTextView);
    final EditText membersEditText = findViewById(R.id.membersEditText);
    Button addButton = findViewById(R.id.addButton);

    addButton.setOnClickListener(new View.OnClickListener() {
        @Override
        public void onClick(View v) {
            Intent intent = new Intent(AddMembers.this, HomePage.class);
            String names = String.valueOf(membersEditText.getText());

            Bundle data = new Bundle();
            MembersFragment membersFragment = new MembersFragment();

            startActivity(intent);

            data.putString("name", names);
            membersFragment.setArguments(data);
        }
    });
}

}

这是我的MembersFragment.class src代码：

private MembersViewModel membersViewModel;
String mParam;

public View onCreateView(@NonNull LayoutInflater inflater,
                         ViewGroup container, Bundle bundle) {
    membersViewModel =
            ViewModelProviders.of(this).get(MembersViewModel.class);
    View root = inflater.inflate(R.layout.fragment_members, container, false);

    if (getArguments() != null) {
        mParam = getArguments().getString("name");
    }

    final TextView textView = root.findViewById(R.id.text_members);
    membersViewModel.getText().observe(getViewLifecycleOwner(), new Observer<String>() {
        @Override
        public void onChanged(@Nullable String s) {
            textView.setText(s);
        }
    });
    return root;
}

Answer 1

当目标是片段时，您不应使用startActivity，请在AddMembers活动中插入以下代码：

Bundle bundle = new Bundle();
bundle.putString("name", "From Activity");
Fragmentclass fragobj = new Fragmentclass();
fragobj.setArguments(bundle);

并尝试在MemberFragment中获取发送的数据：

@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
    Bundle savedInstanceState) {
    String strtext = getArguments().getString("name");    
    return inflater.inflate(R.layout.fragment, container, false);
  }

Answer 2

您必须在调用startActivity()

之前将数据添加到意图中

intent.putExtra(key, value);

然后您通过调用获取值

String value = getIntent().getExtras().getString(key)

Answer 3

我希望这段代码对您有帮助：
AddMembers.class

Bundle bundle = new Bundle();
bundle.putString("name", membersEditText.getText().toString());

MembersFragment frag = new MembersFragment();
frag.setArguments(bundle);

MembersFragment.class

    String name = getArguments().getString("name");    
    return inflater.inflate(R.layout.fragment, container, false);

将数据从活动发送到片段？

3 个答案: