使用Bundle。这里有一个例子:

Fragment fragment = new Fragment();
Bundle bundle = new Bundle();
bundle.putInt(key, value);
fragment.setArguments(bundle);

Bundle为许多数据类型提供了方法。看到这个

然后在你的片段，检索数据(例如在onCreate()方法):

Bundle bundle = this.getArguments();
if (bundle != null) {
        int myInt = bundle.getInt(key, defaultValue);
}

来自活动课:

使用bundle参数将数据发送到片段并加载片段

   Fragment fragment = new myFragment();
   Bundle bundle = new Bundle();
   bundle.putString("pName", personName);
   bundle.putString("pEmail", personEmail);
   bundle.putString("pId", personId);
   fragment.setArguments(bundle);

   getSupportFragmentManager().beginTransaction().replace(R.id.fragment_container,
                    fragment).commit();

从myFragment类:

从bundle中获取参数并将它们设置为xml

    Bundle arguments = getArguments();
    String personName = arguments.getString("pName");
    String personEmail = arguments.getString("pEmail");
    String personId = arguments.getString("pId");

    nameTV = v.findViewById(R.id.name);
    emailTV = v.findViewById(R.id.email);
    idTV = v.findViewById(R.id.id);

    nameTV.setText("Name: "+ personName);
    emailTV.setText("Email: "+ personEmail);
    idTV.setText("ID: "+ personId);

            First Fragment Sending String To Next Fragment
            public class MainActivity extends AppCompatActivity {
                    private Button Add;
                    private EditText edt;
                    FragmentManager fragmentManager;
                    FragClass1 fragClass1;


                    @Override
                    protected void onCreate(Bundle savedInstanceState) {
                        super.onCreate(savedInstanceState);
                        setContentView(R.layout.activity_main);
                        Add= (Button) findViewById(R.id.BtnNext);
                        edt= (EditText) findViewById(R.id.editText);

                        Add.setOnClickListener(new View.OnClickListener() {
                            @Override
                            public void onClick(View v) {
                                fragClass1=new FragClass1();
                                Bundle bundle=new Bundle();

                                fragmentManager=getSupportFragmentManager();
                                fragClass1.setArguments(bundle);
                                bundle.putString("hello",edt.getText().toString());
                                FragmentTransaction fragmentTransaction=fragmentManager.beginTransaction();
                                fragmentTransaction.add(R.id.activity_main,fragClass1,"");
                                fragmentTransaction.addToBackStack(null);
                                fragmentTransaction.commit();

                            }
                        });
                    }
                }
         Next Fragment to fetch the string.
            public class FragClass1 extends Fragment {
                  EditText showFrag1;


                    @Nullable
                    @Override
                    public View onCreateView(LayoutInflater inflater, @Nullable ViewGroup container, @Nullable Bundle savedInstanceState) {

                        View view=inflater.inflate(R.layout.lay_frag1,null);
                        showFrag1= (EditText) view.findViewById(R.id.edtText);
                        Bundle bundle=getArguments();
                        String a=getArguments().getString("hello");//Use This or The Below Commented Code
                        showFrag1.setText(a);
                        //showFrag1.setText(String.valueOf(bundle.getString("hello")));
                        return view;
                    }
                }
    I used Frame Layout easy to use.
    Don't Forget to Add Background color or else fragment will overlap.
This is for First Fragment.
    <FrameLayout xmlns:android="http://schemas.android.com/apk/res/android"
        xmlns:tools="http://schemas.android.com/tools"
        android:id="@+id/activity_main"
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        android:paddingBottom="@dimen/activity_vertical_margin"
        android:paddingLeft="@dimen/activity_horizontal_margin"
        android:paddingRight="@dimen/activity_horizontal_margin"
        android:paddingTop="@dimen/activity_vertical_margin"
        android:background="@color/colorPrimary"
        tools:context="com.example.sumedh.fragmentpractice1.MainActivity">

        <EditText
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            android:id="@+id/editText" />
        <Button
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            android:layout_gravity="center"
            android:id="@+id/BtnNext"/>
    </FrameLayout>


Xml for Next Fragment.
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:orientation="vertical" android:layout_width="match_parent"
   android:background="@color/colorAccent"
    android:layout_height="match_parent">
    <EditText
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:id="@+id/edtText"/>

</LinearLayout>

只是扩展一下前面的答案——它可以帮助到一些人。如果你的getArguments()返回null，把它放在onCreate()方法，而不是你的片段的构造函数:

@Override
public void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    int index = getArguments().getInt("index");
}

如果你正在使用kotlin，那么你可以传递bundle as

val fragment = YourFragment()
val bundle = Bundle().apply {
    putInt("someInt", 5)
    putString("someString", "Hello")
}
fragment.arguments = bundle

在YourFragment的onCreate中获取这些值

this.arguments?.let {
    val someInt    = it.getInt("someInt", someDefaultInt)
    val someString = it.getString("someString", someDefaultString)
}

getArguments()返回null因为“它没有得到任何东西”

试试这段代码来处理这种情况

if(getArguments()!=null)
{
int myInt = getArguments().getInt(key, defaultValue);
}