将代码添加到 Bottomnavigtaionview 中的片段文件

Question

我想知道如何在片段.java文件中编码。首先，我是编码初学者。我在底部航空栏中创建了一个带有三个导航按钮的底部导航视图，并且为每个导航按钮创建了片段活动。底部导航栏中的导航选项之一是"更多"，我添加了一个带有 id"btn_Logoff"的按钮。当我单击按钮时，我希望它activity_login.xml或LoginActivity.java。我不知道代码是什么，以及在默认片段 java 文件中添加代码的位置，所以这是默认情况下写在片段文件上的内容：

文件名为MoreFragment.java

import android.app.Activity;
import android.content.Context;
import android.content.Intent;
import android.net.Uri;
import android.os.Bundle;
import android.support.v4.app.Fragment;
import android.util.Log;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.Button;
import android.widget.LinearLayout;
import android.widget.Toast;

/**
* A simple {@link Fragment} subclass.
* Activities that contain this fragment must implement the
* {@link MoreFragment.OnFragmentInteractionListener} interface
* to handle interaction events.
* Use the {@link MoreFragment#newInstance} factory method to
* create an instance of this fragment.
*/
public class MoreFragment extends Fragment {
// TODO: Rename parameter arguments, choose names that match
// the fragment initialization parameters, e.g. ARG_ITEM_NUMBER
private static final String ARG_PARAM1 = "param1";
private static final String ARG_PARAM2 = "param2";
// TODO: Rename and change types of parameters
private String mParam1;
private String mParam2;
private OnFragmentInteractionListener mListener;
public MoreFragment() {
// Required empty public constructor
}
/**
* Use this factory method to create a new instance of
* this fragment using the provided parameters.
*
* @param param1 Parameter 1.
* @param param2 Parameter 2.
* @return A new instance of fragment MoreFragment.
*/
// TODO: Rename and change types and number of parameters
public static MoreFragment newInstance(String param1, String param2) {
MoreFragment fragment = new MoreFragment();
Bundle args = new Bundle();
args.putString(ARG_PARAM1, param1);
args.putString(ARG_PARAM2, param2);
fragment.setArguments(args);
return fragment;
}
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
if (getArguments() != null) {
mParam1 = getArguments().getString(ARG_PARAM1);
mParam2 = getArguments().getString(ARG_PARAM2);
}
}
@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
// Inflate the layout for this fragment
return inflater.inflate(R.layout.fragment_more, container, false);
}
// TODO: Rename method, update argument and hook method into UI event
public void onButtonPressed(Uri uri) {
if (mListener != null) {
mListener.onFragmentInteraction(uri);
}
}
@Override
public void onAttach(Context context) {
super.onAttach(context);
if (context instanceof OnFragmentInteractionListener) {
mListener = (OnFragmentInteractionListener) context;
} else {
Toast.makeText(context, "Notification Fragment Attached", Toast.LENGTH_SHORT).show();
}
}
@Override
public void onDetach() {
super.onDetach();
mListener = null;
}
/**
* This interface must be implemented by activities that contain this
* fragment to allow an interaction in this fragment to be communicated
* to the activity and potentially other fragments contained in that
* activity.
* <p>
* See the Android Training lesson <a href=
* "http://developer.android.com/training/basics/fragments/communicating.html"
* >Communicating with Other Fragments</a> for more information.
*/
public interface OnFragmentInteractionListener {
// TODO: Update argument type and name
void onFragmentInteraction(Uri uri);
}
}

我一直在尝试和错误，但仍然没有解决方案。任何帮助表示赞赏。谢谢。

Answer 1

你能解释一下这部分吗？

当我单击按钮时，我希望它转到activity_login.xml或登录活动.java。

您想在单击片段中的按钮后在活动中执行某些内容，对吗？

您可以通过某些方式做到这一点。最简单的方法是设置当您单击按钮时收听的侦听器。

1. 创建接口：

   public interface OnNavigationButtonClickListener {
   void onMoreClick();
   }
   

2. 在片段中创建侦听器变量：

   private OnNavigationButtonClickListener navigationListener;
   

   并为其设置：

   public void setNavigationListener(OnNavigationButtonClickListener listener) {
   this.navigationListener = listener;
   }
   

3.在点击更多按钮时片段通知听众：

onMoreButton.setOnClickListener(new OnClickListener {
navigationListener.onMoreClick();
});

4. 然后在您的活动中设置侦听器：

@Override
protected void onCreate(@Nullable Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
fragment.setNavigationListener(new OnNavigationButtonClickListener() {
@Override
public void onMoreClick() {
// you clicked 'more' button in fragment
// do what you want
}
});

Answer 2

假设你已经用findViewById和所有内容识别btn_Logoff 您需要做的就是添加一个启动所需活动的 onclickListener，您的 clickListener 代码将如下所示

Button btn_Logoff;
your class{
btn_Logoff  = (Button)  findViewById(R.id.IdOfYourBtnInTheXmlFile);

btn_Logoff.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
Intent intent = new Intent(getApplicationContext(), LoginActivity.class);
startActivity(intent);
}
});
}