笔记 -- 04 -- ScrollView嵌套listView显示不全

01、ScrollView嵌套ListView显示不全的问题 -- 方法计算条目高度

/**     * scrollview嵌套listview显示不全解决     *     * @param listView     */    public static void setListViewHeightBasedOnChildren(ListView listView) {        ListAdapter listAdapter = listView.getAdapter();        if (listAdapter == null) {            // pre-condition            return;        }        int totalHeight = 0;        for (int i = 0; i < listAdapter.getCount(); i++) {            View listItem = listAdapter.getView(i, null, listView);            listItem.measure(0, 0);            totalHeight += listItem.getMeasuredHeight();        }        ViewGroup.LayoutParams params = listView.getLayoutParams();        params.height = totalHeight                + (listView.getDividerHeight() * (listAdapter.getCount() - 1));        listView.setLayoutParams(params);    }

02、ScrollView嵌套ListView 或者GridView -- 扩展ListView或者GridView 

/** * 解决ScollView嵌套ListView 内容显示不全 */public class ScollViewListView extends ListView {    public ScollViewListView(Context context) {        super(context);    }    public ScollViewListView(Context context, AttributeSet attrs) {        super(context, attrs);    }    public ScollViewListView(Context context, AttributeSet attrs, int defStyle) {        super(context, attrs, defStyle);    }    @Override    protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {        int expandSpec = MeasureSpec.makeMeasureSpec(Integer.MAX_VALUE >> 2, MeasureSpec.AT_MOST);        super.onMeasure(widthMeasureSpec, expandSpec);    }}

03、ScrollView 自定义滑动监听

public class MyScrollView extends ScrollView {    private OnScrollistener onScrollistener;    public OnScrollistener getOnScrollistener() {        return onScrollistener;    }    public void setOnScrollistener(OnScrollistener onScrollistener) {        this.onScrollistener = onScrollistener;    }    public MyScrollView(Context context, AttributeSet attrs, int defStyle) {        super(context, attrs, defStyle);    }    public MyScrollView(Context context, AttributeSet attrs) {        super(context, attrs);    }    public MyScrollView(Context context) {        super(context);    }    public interface OnScrollistener {        void onScroll(int startY, int endY);    }    @Override    protected void onScrollChanged(int l, int t, int oldl, int oldt) {        onScrollistener.onScroll(oldt, t);        super.onScrollChanged(l, t, oldl, oldt);    }}

使用

mLevelPrivilege.setOnScrollistener(new MyScrollView.OnScrollistener() {            @Override            public void onScroll(int startY, int endY) {                //根据scrollview滑动更改标题栏透明度                dynamicChangeAphla(startY, endY);            }        });

透明度设置

 /**     * 根据内容窗体的移动改变标题栏背景透明度     *     * @param startY scrollview开始滑动的y坐标（相对值）     * @param endY   scrollview结束滑动的y坐标（相对值）     */    private void dynamicChangeAphla(int startY, int endY) {        //获取标题高度        int titleHeight = llayoutLevelTitle.getMeasuredHeight();        //获取背景高度        int backHeight = rlayoutLevelTitle.getMeasuredHeight();        //获取控件的绝对位置坐标        int[] location = new int[2];        rlayoutLevelTitle.getLocationInWindow(location);        //从屏幕顶部到控件顶部的坐标位置Y        int currentY = location[1];        //表示回到原位（滑动到顶部）        if (currentY >= 0) {            llayoutLevelTitle.getBackground().mutate().setAlpha(0);        }        DevUtil.e("zpan","=titleHeight=" + titleHeight + "=backHeight=" + backHeight + "=currentY="+currentY);        //颜色透明度改变        if (currentY < titleHeight && currentY >= - (backHeight - titleHeight)) {            //计算出滚动过程中改变的透明值            double y = Math.abs(currentY) * 1.0;            double height = (backHeight - titleHeight) * 1.0;            int changeValue = (int) (y / height * 255);            DevUtil.e("zpan", "changeValue=" + changeValue);            //判断是向上还是向下            if (endY > startY) {//向上;透明度值增加，实际透明度减小                llayoutLevelTitle.getBackground().mutate().setAlpha(changeValue);            } else if (endY < startY) {//向下；透明度值减小，实际透明度增加                llayoutLevelTitle.getBackground().mutate().setAlpha(changeValue);            }        }        //红色背景移除屏幕        if (currentY < -(backHeight - titleHeight)) {            llayoutLevelTitle.getBackground().mutate().setAlpha(255);        }    }