无法解析方法findViewByID（int）片段java

Question

错误：更新

尝试使用GetView.findViewById错误无法解决方法GetView 试图仅使用findViewById错误无法解决findViewById(int)

＆＃13;

＆＃13;

package com.example.user.myapplication.Tabs;

import android.animation.Animator;
import android.animation.ValueAnimator;
import android.os.Bundle;
import android.support.annotation.Nullable;
import android.support.v4.app.Fragment;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.view.ViewTreeObserver;
import android.widget.LinearLayout;

import com.example.user.myapplication.R;

public class Hotel extends Fragment {

    LinearLayout mLinearLayout;
    LinearLayout mLinearLayoutHeader;
    ValueAnimator mAnimator;

    @Override
    public View onCreateView(LayoutInflater inflater, @Nullable ViewGroup container, @Nullable Bundle savedInstanceState) {
        View v =inflater.inflate(R.layout.hotel_frag,container,false);
        return v;

       mLinearLayout = (LinearLayout) v.findViewById(R.id.expandable);
        //mLinearLayout.setVisibility(View.GONE);
        mLinearLayoutHeader = (LinearLayout) v.findViewById(R.id.header);

        //Add onPreDrawListener
        mLinearLayout.getViewTreeObserver().addOnPreDrawListener(
                new ViewTreeObserver.OnPreDrawListener() {

                    @Override
                    public boolean onPreDraw() {
                        mLinearLayout.getViewTreeObserver().removeOnPreDrawListener(this);
                        mLinearLayout.setVisibility(View.GONE);

                        final int widthSpec = View.MeasureSpec.makeMeasureSpec(0, View.MeasureSpec.UNSPECIFIED);
                        final int heightSpec = View.MeasureSpec.makeMeasureSpec(0, View.MeasureSpec.UNSPECIFIED);
                        mLinearLayout.measure(widthSpec, heightSpec);

                        mAnimator = slideAnimator(0, mLinearLayout.getMeasuredHeight());
                        return true;
                    }
                });


        mLinearLayoutHeader.setOnClickListener(new View.OnClickListener() {

            @Override
            public void onClick(View v) {
                if (mLinearLayout.getVisibility()==View.GONE){
                    expand();
                }else{
                    collapse();
                }
            }
        });

        return v;
    }


    private void expand() {
        //set Visible
        mLinearLayout.setVisibility(View.VISIBLE);

		/* Remove and used in preDrawListener
		final int widthSpec = View.MeasureSpec.makeMeasureSpec(0, View.MeasureSpec.UNSPECIFIED);
		final int heightSpec = View.MeasureSpec.makeMeasureSpec(0, View.MeasureSpec.UNSPECIFIED);
		mLinearLayout.measure(widthSpec, heightSpec);

		mAnimator = slideAnimator(0, mLinearLayout.getMeasuredHeight());
		*/

        mAnimator.start();
    }

    private void collapse() {
        int finalHeight = mLinearLayout.getHeight();

        ValueAnimator mAnimator = slideAnimator(finalHeight, 0);

        mAnimator.addListener(new Animator.AnimatorListener() {
            @Override
            public void onAnimationEnd(Animator animator) {
                //Height=0, but it set visibility to GONE
                mLinearLayout.setVisibility(View.GONE);
            }

            @Override
            public void onAnimationStart(Animator animator) {
            }

            @Override
            public void onAnimationCancel(Animator animator) {
            }

            @Override
            public void onAnimationRepeat(Animator animator) {
            }
        });
        mAnimator.start();

    }


    private ValueAnimator slideAnimator(int start, int end) {

        ValueAnimator animator = ValueAnimator.ofInt(start, end);


        animator.addUpdateListener(new ValueAnimator.AnimatorUpdateListener() {
            @Override
            public void onAnimationUpdate(ValueAnimator valueAnimator) {
                //Update Height
                int value = (Integer) valueAnimator.getAnimatedValue();

                ViewGroup.LayoutParams layoutParams = mLinearLayout.getLayoutParams();
                layoutParams.height = value;
                mLinearLayout.setLayoutParams(layoutParams);
            }
        });
        return animator;
    }
}

＆＃13;

＆＃13;

＆＃13;

Answer 1

请在oncreate方法结束时给出return语句。

    @Override
     public View onCreateView(LayoutInflater inflater, @Nullable ViewGroup container, @Nullable Bundle savedInstanceState) {
            View v =inflater.inflate(R.layout.hotel_frag,container,false);

----------------- your code -----------------

            return v;
}

Answer 2

试试这个

mLinearLayout = (LinearLayout) v.findViewById(R.id.expandable);

和'return v'应该是onCreateView方法的最后一行

Ur方法应如下所示

@Override
public View onCreateView(LayoutInflater inflater, @Nullable ViewGroup container, @Nullable Bundle savedInstanceState) {
    View v =inflater.inflate(R.layout.hotel_frag,container,false);

   mLinearLayout = (LinearLayout) v.findViewById(R.id.expandable);
    //mLinearLayout.setVisibility(View.GONE);
    mLinearLayoutHeader = (LinearLayout) v.findViewById(R.id.header);

    //Add onPreDrawListener
    mLinearLayout.getViewTreeObserver().addOnPreDrawListener(
            new ViewTreeObserver.OnPreDrawListener() {

                @Override
                public boolean onPreDraw() {
                    mLinearLayout.getViewTreeObserver().removeOnPreDrawListener(this);
                    mLinearLayout.setVisibility(View.GONE);

                    final int widthSpec = View.MeasureSpec.makeMeasureSpec(0, View.MeasureSpec.UNSPECIFIED);
                    final int heightSpec = View.MeasureSpec.makeMeasureSpec(0, View.MeasureSpec.UNSPECIFIED);
                    mLinearLayout.measure(widthSpec, heightSpec);

                    mAnimator = slideAnimator(0, mLinearLayout.getMeasuredHeight());
                    return true;
                }
            });


    mLinearLayoutHeader.setOnClickListener(new View.OnClickListener() {

        @Override
        public void onClick(View v) {
            if (mLinearLayout.getVisibility()==View.GONE){
                expand();
            }else{
                collapse();
            }
        }
    });

    return v;
}