fragment传值给activity：接口

步骤

1、fragment中定义接口，并设置数据

2、activity实现接口

示例：

FragmentA ：发送方

public class FragmentA extends Fragment { private EditText et; private FragmentACallBack fragmentACallBack; public interface FragmentACallBack {//定义接口 void setData(String data); } @Override public void onAttach(Activity activity) { super.onAttach(activity); fragmentACallBack = (FragmentACallBack) getActivity();//实例化接口 } @Nullable @Override public View onCreateView(LayoutInflater inflater, @Nullable ViewGroup container, Bundle savedInstanceState) { View view = inflater.inflate(R.layout.layout_a, container, false); et = (EditText) view.findViewById(R.id.et); Button bt = (Button) view.findViewById(R.id.bt); bt.setOnClickListener(new View.OnClickListener() { @Override public void onClick(View v) { fragmentACallBack.setData(et.getText().toString());//接口传递数据 } }); return view; } }

布局：

<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android" android:layout_width="match_parent" android:layout_height="match_parent" android:background="#00ff00" android:gravity="center" android:orientation="vertical"> <EditText android:id="@+id/et" android:layout_width="match_parent" android:layout_height="wrap_content" android:textSize="30sp" /> <Button android:id="@+id/bt" android:layout_width="wrap_content" android:layout_height="wrap_content" android:text="发送" android:textSize="30sp" /> </LinearLayout>

MainActivityII ：接收方

public class MainActivityII extends FragmentActivity implements FragmentA.FragmentACallBack { private FragmentA fragmentA; @Override protected void onCreate(@Nullable Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.activity_mainii); fragmentA = new FragmentA(); //添加fragment getFragmentManager().beginTransaction().replace(R.id.container_a, fragmentA, "fragmentA").commit(); } @Override public void setData(String data) {//实现接口 //获取到FragmentA传递过来的数据data } }

布局：

<?xml version="1.0" encoding="utf-8"?> <LinearLayout xmlns:android="http://schemas.android.com/apk/res/android" android:layout_width="match_parent" android:layout_height="match_parent" android:orientation="vertical"> <LinearLayout android:id="@+id/container_a" android:layout_width="match_parent" android:layout_height="0dp" android:layout_weight="1" android:background="@color/colorAccent" android:orientation="horizontal" /> </LinearLayout>