ScrollView 嵌套listview 如果子item数量多的话 listview高度不准确问题

来源：互联网发布：java打印空心三角形编辑：程序博客网时间：2024/05/22 02:30

<pre name="code" class="java">重新写一个类  继承 ListView

重写

onTouch    onScroll

onMeasure

三个方法

onMeasure计算listview 的高度

</pre><pre name="code" class="java">

package com.jyt.msct.famousteachertitle.view;import android.annotation.SuppressLint;import android.content.Context;import android.util.AttributeSet;import android.view.MotionEvent;import android.view.View;import android.view.View.OnTouchListener;import android.view.ViewGroup;import android.widget.AbsListView;import android.widget.AbsListView.OnScrollListener;import android.widget.ListAdapter;import android.widget.ListView;@SuppressLint("DrawAllocation")public class MyListView extends ListView implements OnTouchListener,OnScrollListener {private int listViewTouchAction;private static final int MAXIMUM_LIST_ITEMS_VIEWABLE = 99;public MyListView(Context context, AttributeSet attrs) {super(context, attrs);listViewTouchAction = -1;setOnScrollListener(this);setOnTouchListener(this);}@Overridepublic void onScroll(AbsListView view, int firstVisibleItem,int visibleItemCount, int totalItemCount) {if (getAdapter() != null&& getAdapter().getCount() > MAXIMUM_LIST_ITEMS_VIEWABLE) {if (listViewTouchAction == MotionEvent.ACTION_MOVE) {scrollBy(0, -1);}}}@Overridepublic void onScrollStateChanged(AbsListView view, int scrollState) {}@Overrideprotected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {super.onMeasure(widthMeasureSpec, heightMeasureSpec);int newHeight = 0;final int heightMode = MeasureSpec.getMode(heightMeasureSpec);int heightSize = MeasureSpec.getSize(heightMeasureSpec);if (heightMode != MeasureSpec.EXACTLY) {ListAdapter listAdapter = getAdapter();if (listAdapter != null && !listAdapter.isEmpty()) {int listPosition = 0;for (listPosition = 0; listPosition < listAdapter.getCount()&& listPosition < MAXIMUM_LIST_ITEMS_VIEWABLE; listPosition++) {View listItem = listAdapter.getView(listPosition, null,this);// now it will not throw a NPE if listItem is a ViewGroup// instanceif (listItem instanceof ViewGroup) {listItem.setLayoutParams(new LayoutParams(LayoutParams.WRAP_CONTENT,LayoutParams.WRAP_CONTENT));}listItem.measure(widthMeasureSpec, heightMeasureSpec);newHeight += listItem.getMeasuredHeight();}newHeight += getDividerHeight() * listPosition;}if ((heightMode == MeasureSpec.AT_MOST) && (newHeight > heightSize)) {if (newHeight > heightSize) {newHeight = heightSize;}}} else {newHeight = getMeasuredHeight();}setMeasuredDimension(getMeasuredWidth(), newHeight);}@Overridepublic boolean onTouch(View v, MotionEvent event) {if (getAdapter() != null&& getAdapter().getCount() > MAXIMUM_LIST_ITEMS_VIEWABLE) {if (listViewTouchAction == MotionEvent.ACTION_MOVE) {scrollBy(0, 1);}}return false;}}

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