获取错误"无法解析findViewById(int)"

Question

我有一个主要的活动,当我按下一个按钮时,我导航到一个滑动选项卡视图.现在我希望在这些选项卡中有一个可点击按钮,并在按下按钮时显示一个Toast.这是我使用的代码:

import android.os.Bundle;
import android.support.v4.app.Fragment;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.Button;

public class laundry extends Fragment {
Button btn_service;
@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
                         Bundle savedInstanceState) {
    // TODO Auto-generated method stub
    return inflater.inflate(R.layout.activity_laundry, container,false);
    btn_service = (Button) findViewById(R.id.btn_service);
    btn_service.setOnClickListener(this);
}

但findViewById不是此活动的已知符号.是否有另一种方法可以在上面的片段活动中加入可点击按钮？

跑了项目,我得到了这个错误.(我不知道建议的更改是否有效,我的应用程序崩溃了以下错误)这是一个片段活动,我试图在单击按钮时生成一个Toast.

public class in_room_dining extends Fragment
{
Button btn_order;
@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
                         Bundle savedInstanceState)
{
    // TODO Auto-generated method stub

    btn_order.setOnClickListener(new OnClickListener()
{
 public void onClick(View v)
{
Toast.makeText(getActivity(), "text", Toast.LENGTH_SHORT).show();
}
});
 return inflater.inflate(R.layout.activity_in_room_dining, container, false);
}
}

我得到的错误是:

11-29 10:57:42.820      938-938/com.appt.shreyabisht.staymax E/AndroidRuntime? FATAL EXCEPTION:     main
Process: com.appt.shreyabisht.staymax, PID: 938
java.lang.NullPointerException
        at com.appt.shreyabisht.staymax.in_room_dining.onCreateView(in_room_dining.java:23)
        at android.support.v4.app.Fragment.performCreateView(Fragment.java:1504)

(in_room_dining.java:23)是btn_order.setOnClickListener(new OnClickListener())

Answer 1

import android.os.Bundle;
import android.support.v4.app.Fragment;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.Button;

public class laundry extends Fragment {
Button btn_service;
@Override 
public View onCreateView(LayoutInflater inflater, ViewGroup container,
                         Bundle savedInstanceState) {
    // TODO Auto-generated method stub 
final View rootView = inflater.inflate(R.layout.activity_laundry, container,
                false);

    btn_service = (Button) rootView.findViewById(R.id.btn_service);
    btn_service.setOnClickListener(new OnClickListener() {

        @Override
        public void onClick(View v) {

         //your Code Goes Here    
        }
    });
    return rootView;
}