静态添加的碎片中相互通信

左手的ㄟ右手 2022-09-26 01:59 22阅读 0赞

在静态添加的碎片中通信要借助他们的宿主Activity,（插句题外话：在activity中findViewById()只能寻找到setContentView()加载的布局中的控件，不在里面的控件是找不到的

一个通信小例子，右边Fragment中包含一个Button，左边Fragment包含一个TextView，点击右边Fragment中的Button可以改变左边Fragment中文本中的文字，

右边Fragment中的布局

右碎片

public class RightFragment extends Fragment {
    
        
        private Button button;
        @Nullable
        @Override
        public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
            View view = inflater.inflate(R.layout.right_fragment, container,false);
            button =(Button) view.findViewById(R.id.button);
    
            return view;
        }
        public void changeContent(final TextView getView){
            button.setOnClickListener(new View.OnClickListener() {
                @Override
                public void onClick(View view) {
                    getView.setText("change by right");
                    Log.d("test", "button click");
                }
            });
        } 左边碎片的布局 <LinearLayout xmlns:android="http://schemas.android.com/apk/res/android" android:orientation="vertical" android:layout_width="match_parent" android:layout_height="match_parent" android:background="@android:color/holo_red_light">
    
        <TextView android:layout_width="wrap_content" android:layout_height="wrap_content" android:id="@+id/left1" android:text="this is left fragment"/>
    
    </LinearLayout> 左边碎片 public class leftFragment extends Fragment {
        RightFragmentListener callBack;
        @Nullable
        @Override
        public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
            View view = inflater.inflate(R.layout.left_fragment, container);
            return view;
        }
    } 
     宿主Activity public class MyActivity extends FragmentActivity {
        private TextView textView;
        @Override
        protected void onCreate(@Nullable Bundle savedInstanceState) {
            super.onCreate(savedInstanceState);
            setContentView(R.layout.content);
            //如果布局content中不包括控某件的话，用findViewById(R.id.left1)是找不到该控件的 /*TextView textView = (TextView) findViewById(R.id.left1); textView.setText("aa");*/ TextView textView = (TextView) findViewById(R.id.left1);
            RightFragment rightFragment = (RightFragment) getFragmentManager().findFragmentById(R.id.right);
            rightFragment.changeContent(textView);
        }

宿主中的布局