Android scrollView and viewpager nested indicator ceiling adapts height according to the content of each page of viewpager

A friend asked me a question in the past few days. I have a special requirement. The page is as follows

That is, when the content of the current page in the viewpager is enough, it can slide up and the indicator is on the top, but when there is not much content, it can slide to where it is and stop there. At that time, the first reaction was to use coordinatelayout. slid directly to the top

xml file of activity

<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:id="@+id/main_content"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:orientation="vertical">
    <com.example.wenlaisu.myapplication.MyScrollview
android:id="@+id/scroll"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:fillViewport="true">
        <LinearLayout
                

                                
            android:layout_width="match_parent"
android:layout_height="match_parent"
android:orientation="vertical">
            <ImageView
android:layout_width="match_parent"
android:layout_height="200dp"
android:background="?attr/colorPrimary"
android:scaleType="fitXY"
android:id="@+id/iv"
android:src="@drawable/tangyan" />
            <LinearLayout
android:id="@+id/layout"
android:layout_width=                        
                                                                                                
                                "match_parent"
android:layout_height="wrap_content">
                <android.support.design.widget.TabLayout
android:id="@+id/tabs"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:background="?attr/colorPrimary" />
            </LinearLayout>
            <com.example.wenlaisu.myapplication.CustomViewPager
android:id="@+id/viewpager"
android:layout_width="match_parent"
android:layout_height="wrap_content" />
                
                                                                                

                                                        </LinearLayout>
    </com.example.wenlaisu.myapplication.MyScrollview>

    <RelativeLayout
        android:id="@+id/rl_layout"
        android:layout_width="match_parent"
        android:layout_height="wrap_content" >

    </RelativeLayout>
</RelativeLayout>

后来就直接用scrollView包裹来实现了自定义scrollView实现滚动监听用来实现指示器吸顶效果

public class MyScrollview extends ScrollView {

    private ScrollViewListener scrollViewListener = null;

    public MyScrollview(Context context) {
        super(context);
    }

    public MyScrollview(Context context, AttributeSet attrs) {
        super(context, attrs);
    }

    public MyScrollview(Context context, AttributeSet attrs, int defStyleAttr) {
        super(context, attrs, defStyleAttr);
    }

    public void setScrollViewListener(ScrollViewListener scrollViewListener) {
        this.scrollViewListener = scrollViewListener;
    }

    @Override
    protected void onScrollChanged(int l, int t, int oldl, int oldt) {
        super.onScrollChanged(l, t, oldl, oldt);
        if (scrollViewListener != null) {
            scrollViewListener.onScrollChanged(this, l, t, oldl, oldt);
        }
    }

    public interface ScrollViewListener {
        void onScrollChanged(MyScrollview scrollView, int l, int t, int oldl, int oldt);
    }
}

在activity里面设置监听

scroll.setScrollViewListener(new MyScrollview.ScrollViewListener() {
    @Override
    public void onScrollChanged(MyScrollview scrollView, int l, int t, int oldl, int oldt) {
        if (t >iv.getHeight() && mTabLayout.getParent() == layout) {
            layout.removeView(mTabLayout);
            rl_layout.addView(mTabLayout);
        } else if (t < iv.getHeight() && mTabLayout.getParent() == rl_layout) {
            rl_layout.removeView(mTabLayout);
            layout.addView(mTabLayout);
        }
    }
});

然后就是实现viewpager的每个页面的内容高度适配了从写viewpager

public class CustomViewPager extends ViewPager {
  
    private int current;  
    private int height = 0;  
    /**  
     * 保存position与对于的View  
     */  
    private HashMap<Integer, View> mChildrenViews = new LinkedHashMap<Integer, View>();
  
    private boolean scrollble = true;  
  
    public CustomViewPager(Context context) {
        super(context);  
    }  
  
    public CustomViewPager(Context context, AttributeSet attrs) {
        super(context, attrs);  
    }  
  
  
    @Override  
    protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {  
        if (mChildrenViews.size() > current) {  
            View child = mChildrenViews.get(current);  
            if (child != null) {  
                child.measure(widthMeasureSpec, MeasureSpec.makeMeasureSpec(0, MeasureSpec.UNSPECIFIED));  
                height = child.getMeasuredHeight();  
            }  
        }  
  
        heightMeasureSpec = MeasureSpec.makeMeasureSpec(height, MeasureSpec.EXACTLY);  
  
        super.onMeasure(widthMeasureSpec, heightMeasureSpec);  
    }  
  
    public void resetHeight(int current) {  
        this.current = current;  
        if (mChildrenViews.size() > current) {  
  
            LinearLayout.LayoutParams layoutParams = (LinearLayout.LayoutParams) getLayoutParams();
            if (layoutParams == null) {  
                layoutParams = new LinearLayout.LayoutParams(LinearLayout.LayoutParams.WRAP_CONTENT, height);
            } else {  
                layoutParams.height = height;  
            }  
            setLayoutParams(layoutParams);  
        }  
    }  
  
    /**  
     * 保存position与对于的View  
     */  
    public void setObjectForPosition(View view, int position) {  
        mChildrenViews.put(position, view);  
    }  
  
  
    @Override  
    public boolean onTouchEvent(MotionEvent ev) {
        if (!scrollble) {  
            return true;  
        }  
        return super.onTouchEvent(ev);  
    }  
  
  
    public boolean isScrollble() {  
        return scrollble;  
    }  
  
    public void setScrollble(boolean scrollble) {  
        this.scrollble = scrollble;  
    }  
  
  
}

The usage is to add a line of code in the onCreatView of each fragment

Then set the listener in the activity where the viewpager is located.

mViewPager.setOnPageChangeListener(new ViewPager.OnPageChangeListener() {
    @Override
public void onPageScrolled(int position, float positionOffset, int positionOffsetPixels) {    
    }

    @Override
    public void onPageSelected(int position) {
        mViewPager.resetHeight(position);
    }

    @Override
    public void onPageScrollStateChanged(int state) {
    }
});

下面是整个activity的代码

package com.example.wenlaisu.myapplication;

import android.os.Bundle;
import android.support.design.widget.TabLayout;
import android.support.v4.app.Fragment;
import android.support.v4.view.ViewPager;
import android.support.v7.app.AppCompatActivity;
import android.widget.ImageView;
import android.widget.LinearLayout;
import android.widget.RelativeLayout;
import java.util.ArrayList;
import java.util.List;
/**
 * Created by wenlaisu on 2018/4/12.
 */
public class ViewPagerSample extends AppCompatActivity {

    CustomViewPager mViewPager;
    List<Fragment> mFragments;

    String[] mTitles = new String[]{
            "主页", "微博", "相册"
    };
    private TabLayout mTabLayout;
    private MyScrollview scroll;
    private LinearLayout layout;
    private RelativeLayout rl_layout;
    private ImageView iv;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_third);
        // 第一步，初始化ViewPager和TabLayout
        mViewPager = (CustomViewPager) findViewById(R.id.viewpager);
        mTabLayout = (TabLayout) findViewById(R.id.tabs);
        layout = (LinearLayout) findViewById(R.id.layout);
        rl_layout = (RelativeLayout) findViewById(R.id.rl_layout);
        scroll = (MyScrollview) findViewById(R.id.scroll);
        iv = (ImageView) findViewById(R.id.iv);
        setupViewPager();
    }



    private void setupViewPager() {

        mFragments = new ArrayList<>();
        ListFragment listFragment = new ListFragment(mViewPager, 0);
        ListFragment2 listFragment2 = new ListFragment2(mViewPager, 1);
        ListFragment3 listFragment3 = new ListFragment3(mViewPager, 2);
        mFragments.add(listFragment);
        mFragments.add(listFragment2);
        mFragments.add(listFragment3);

        // 第二步：为ViewPager设置适配器
        BaseFragmentAdapter adapter =
                new BaseFragmentAdapter(getSupportFragmentManager(), mFragments, mTitles);

        mViewPager.setAdapter(adapter);
        //  第三步：将ViewPager与TableLayout 绑定在一起
        mTabLayout.setupWithViewPager(mViewPager);

        mViewPager.setOnPageChangeListener(new ViewPager.OnPageChangeListener() {
            @Override
            public void onPageScrolled(int position, float positionOffset, int positionOffsetPixels) {
            }

            @Override
            public void onPageSelected(int position) {
                mViewPager.resetHeight(position);
            }

            @Override
            public void onPageScrollStateChanged(int state) {
            }
        });

        scroll.setScrollViewListener(new MyScrollview.ScrollViewListener() {
            @Override
            public void onScrollChanged(MyScrollview scrollView, int l, int t, int oldl, int oldt) {
                if (t >iv.getHeight() && mTabLayout.getParent() == layout) {
                    layout.removeView(mTabLayout);
                    rl_layout.addView(mTabLayout);
                } else if (t < iv.getHeight() && mTabLayout.getParent() == rl_layout) {
                    rl_layout.removeView(mTabLayout);
layout.addView(mTabLayout);
}                                    
            }
        });
}
    
}

just fine

Android scrollView and viewpager nested indicator ceiling adapts height according to the content of each page of viewpager

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