Android嵌套滑动控件的冲突解决和ViewPager适配当前子控件高度不留空白的办法

• 刚才说了，使用ScrollView作为最外层滑动控件来嵌套其他滑动控件，会有莫名其妙的位移BUG，因此应该换一种滑动控件作为最外层的容器。
• 两个滑动控件嵌套，内部滑动控件的高度默认会是0，除非你用定值设置，如果不想用定值设置，那么就需要自定义这个滑动控件，手动的计算该滑动控件。
• ViewPager嵌套ListView会有数据少的ListView底部出现一大片的空白，因此这里我们也需要自定义ViewPager来动态计算当前的ListView的高度。
• ListView作为顶层滑动控件的子滑动控件ViewPager的子滑动控件，高度默认当然也是0，这里我们也需要进行自定义ListView计算高度。

<?xml version="1.0" encoding="utf-8"?>
<ListView xmlns:android="http://schemas.android.com/apk/res/android"
    android:id="@+id/listView"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:cacheColorHint="@android:color/transparent"
    android:divider="@null"
    android:dividerHeight="0dp"
    android:listSelector="@android:color/transparent" />

public class MainActivity extends FragmentActivity {

    private TabPageIndicator indicator;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);

        ListView listView = (ListView) findViewById(R.id.listView);
        View header = View.inflate(this, R.layout.header, null);
        indicator = (TabPageIndicator) header.findViewById(R.id.indicator);
        listView.addHeaderView(header);
        listView.setAdapter(new CustomAdapter(this));
    }

    public class CustomAdapter extends BaseAdapter{

        private View view;
        private WrapContentViewPager viewPager;

        public CustomAdapter(Context context) {
            view = View.inflate(context, R.layout.item_main, null);
            viewPager = (WrapContentViewPager) view.findViewById(R.id.viewPager);
            viewPager.setAdapter(new ListFragmentAdapter(viewPager, getSupportFragmentManager()));
            indicator.setViewPager(viewPager);
            viewPager.setOnPageChangeListener(new ViewPager.OnPageChangeListener() {
                @Override
                public void onPageScrolled(int position, float positionOffset, int positionOffsetPixels) {

                }

                @Override
                public void onPageSelected(int position) {
                    viewPager.resetHeight(position);
                    indicator.setCurrentItem(position);
                }

                @Override
                public void onPageScrollStateChanged(int state) {

                }
            });
            viewPager.resetHeight(0);
        }

        @Override
        public int getCount() {
            return 1;
        }

        @Override
        public Object getItem(int position) {
            return null;
        }

        @Override
        public long getItemId(int position) {
            return 0;
        }

        @Override
        public View getView(int position, View convertView, ViewGroup parent) {
            return view;
        }
    }
}

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="match_parent"
    android:layout_height="wrap_content"
    android:orientation="vertical"
    >
    <TextView
        android:layout_width="match_parent"
        android:layout_height="80dp"
        android:gravity="center"
        android:background="@android:color/holo_red_light"
        android:text="Hello World!" />
    <TextView
        android:layout_width="match_parent"
        android:layout_height="80dp"
        android:gravity="center"
        android:background="@android:color/holo_blue_light"
        android:text="Hello World!" />
    <TextView
        android:layout_width="match_parent"
        android:layout_height="80dp"
        android:gravity="center"
        android:background="@android:color/holo_orange_light"
        android:text="Hello World!" />
    <TextView
        android:layout_width="match_parent"
        android:layout_height="80dp"
        android:gravity="center"
        android:background="@android:color/holo_green_light"
        android:text="Hello World!" />

    <cc.wxf.androiddemo.indicator.TabPageIndicator
        android:id="@+id/indicator"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"/>
</LinearLayout>

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="match_parent"
    android:layout_height="wrap_content">

    <cc.wxf.androiddemo.WrapContentViewPager
        android:id="@+id/viewPager"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"/>
</LinearLayout>

• 需要知道所有子控件的高度
• 需要重写onMeasure方法，使当前显示的子控件的高度为ViewPager的高度
• 需要在page发生改变的时候，动态改变ViewPager的高度为当前子控件的高度

package cc.wxf.androiddemo;

import android.content.Context;
import android.support.v4.view.ViewPager;
import android.util.AttributeSet;
import android.widget.LinearLayout;

import java.util.HashMap;
import java.util.Map;

public class WrapContentViewPager extends ViewPager {

    private Map<Integer, Integer> maps = new HashMap<Integer, Integer>();
    private int current;

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

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


    @Override
    protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {
        int height = 0;
        if(maps.size() > current){
            height = maps.get(current + 1);
        }
        heightMeasureSpec = MeasureSpec.makeMeasureSpec(height, MeasureSpec.EXACTLY);
        super.onMeasure(widthMeasureSpec, heightMeasureSpec);
    }

    public void resetHeight(int current){
        this.current = current;
        if(maps.size() > current){
            LinearLayout.LayoutParams layoutParams = (LinearLayout.LayoutParams) getLayoutParams();
            if(layoutParams == null){
                layoutParams = new LinearLayout.LayoutParams(LinearLayout.LayoutParams.MATCH_PARENT, maps.get(current + 1));
            }else{
                layoutParams.height = maps.get(current + 1);
            }
            setLayoutParams(layoutParams);
        }
    }

    public void calculate(int type, int height){
        maps.put(type, height);
    }
}

package cc.wxf.androiddemo;

import android.support.v4.app.Fragment;
import android.support.v4.app.FragmentManager;
import android.support.v4.app.FragmentPagerAdapter;

import java.util.ArrayList;
import java.util.List;

import cc.wxf.androiddemo.indicator.IconPagerAdapter;

/**
 * Created by ccwxf on 2016/6/17.
 */
public class ListFragmentAdapter extends FragmentPagerAdapter implements IconPagerAdapter{

    private List<ListFragment> fragments = new ArrayList<ListFragment>();
    private static final String[] CONTENT = new String[] { "Calendar", "Camera", "Alarms", "Location" };

    public ListFragmentAdapter(WrapContentViewPager viewPager, FragmentManager fm) {
        super(fm);

        fragments.add(new ListFragment(viewPager ,1));
        fragments.add(new ListFragment(viewPager, 2));
        fragments.add(new ListFragment(viewPager, 3));
    }

    @Override
    public Fragment getItem(int position) {
        return fragments.get(position);
    }

    @Override
    public int getIconResId(int index) {
        return R.drawable.selector_indicator;
    }

    @Override
    public CharSequence getPageTitle(int position) {
        return CONTENT[position % CONTENT.length].toUpperCase();
    }

    @Override
    public int getCount() {
        return fragments.size();
    }
}

package cc.wxf.androiddemo;

import android.annotation.SuppressLint;
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.widget.ArrayAdapter;

import java.util.ArrayList;
import java.util.List;

/**
 * Created by ccwxf on 2016/6/17.
 */
public class ListFragment extends Fragment {

    private WrapContentViewPager viewPager;
    private int type;

    public ListFragment() {
    }

    @SuppressLint("ValidFragment")
    public ListFragment(WrapContentViewPager viewPager, int type) {
        this.viewPager = viewPager;
        this.type = type;
    }

    @Override
    public View onCreateView(LayoutInflater inflater, @Nullable ViewGroup container, @Nullable Bundle savedInstanceState) {
        View view = inflater.inflate(R.layout.fragment_item, null);
        WrapContentListView listView = (WrapContentListView) view.findViewById(R.id.listView);
        List<String> data = new ArrayList<String>();
        for(int i = 0; i < type * 5; i++){
            data.add("aaa");
        }
        listView.setAdapter(new ArrayAdapter<String>(getActivity(), android.R.layout.simple_list_item_1, data));
        viewPager.calculate(type, listView.getRealHeight());
        return view;
    }
}

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:orientation="vertical" android:layout_width="match_parent"
    android:layout_height="match_parent">

    <cc.wxf.androiddemo.WrapContentListView
        android:id="@+id/listView"
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        android:cacheColorHint="@android:color/transparent"
        android:divider="@android:color/darker_gray"
        android:dividerHeight="@dimen/divider"
        android:listSelector="@android:color/transparent" />
</LinearLayout>

package cc.wxf.androiddemo;

import android.content.Context;
import android.util.AttributeSet;
import android.view.View;
import android.widget.ListAdapter;
import android.widget.ListView;

/**
 * Created by ccwxf on 2016/6/17.
 */
public class WrapContentListView extends ListView {

    private int height;

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

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

    public WrapContentListView(Context context, AttributeSet attrs, int defStyle) {
        super(context, attrs, defStyle);
    }

    @Override
    public void setAdapter(ListAdapter adapter) {
        super.setAdapter(adapter);
        View item = adapter.getView(0, null, null);
        item.measure(MeasureSpec.makeMeasureSpec(0, MeasureSpec.UNSPECIFIED), MeasureSpec.makeMeasureSpec(0, MeasureSpec.UNSPECIFIED));
        int itemHeight = item.getMeasuredHeight();
        int count = adapter.getCount();
        height = itemHeight * count + getResources().getDimensionPixelSize(R.dimen.divider) * count;
        measure(MeasureSpec.makeMeasureSpec(0, MeasureSpec.UNSPECIFIED), height);
    }

    public int getRealHeight(){
        return height;
    }

    @Override
    protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {
        super.onMeasure(widthMeasureSpec, MeasureSpec.makeMeasureSpec(height, MeasureSpec.EXACTLY));
    }
}