我到处寻找这个问题的解决方案,我能找到的唯一答案似乎是“不要把一个ListView放入一个ScrollView”。不过,我还没有看到任何真正的解释。我能找到的唯一原因似乎是谷歌认为你不应该这么做。我知道,所以我做了。
问题是,如何将ListView放到ScrollView中而不缩到最小高度?
我到处寻找这个问题的解决方案,我能找到的唯一答案似乎是“不要把一个ListView放入一个ScrollView”。不过,我还没有看到任何真正的解释。我能找到的唯一原因似乎是谷歌认为你不应该这么做。我知道,所以我做了。
问题是,如何将ListView放到ScrollView中而不缩到最小高度?
当前回答
在很多情况下,在ScrollView中有ListView是很有意义的。
下面是基于DougW建议的代码…工作在一个片段,占用较少的内存。
public static void setListViewHeightBasedOnChildren(ListView listView) {
ListAdapter listAdapter = listView.getAdapter();
if (listAdapter == null) {
return;
}
int desiredWidth = MeasureSpec.makeMeasureSpec(listView.getWidth(), MeasureSpec.AT_MOST);
int totalHeight = 0;
View view = null;
for (int i = 0; i < listAdapter.getCount(); i++) {
view = listAdapter.getView(i, view, listView);
if (i == 0) {
view.setLayoutParams(new ViewGroup.LayoutParams(desiredWidth, LayoutParams.WRAP_CONTENT));
}
view.measure(desiredWidth, MeasureSpec.UNSPECIFIED);
totalHeight += view.getMeasuredHeight();
}
ViewGroup.LayoutParams params = listView.getLayoutParams();
params.height = totalHeight + (listView.getDividerHeight() * (listAdapter.getCount() - 1));
listView.setLayoutParams(params);
listView.requestLayout();
}
在每个嵌入的列表视图上调用setListViewHeightBasedOnChildren(listview)。
其他回答
这肯定会工作............ 你必须替换你的<ScrollView ></ScrollView>在布局XML文件与这个自定义ScrollView像<com.tmd.utils。VerticalScrollview > </com.tmd.utils。VerticalScrollview >
package com.tmd.utils;
import android.content.Context;
import android.util.AttributeSet;
import android.util.Log;
import android.view.MotionEvent;
import android.widget.ScrollView;
public class VerticalScrollview extends ScrollView{
public VerticalScrollview(Context context) {
super(context);
}
public VerticalScrollview(Context context, AttributeSet attrs) {
super(context, attrs);
}
public VerticalScrollview(Context context, AttributeSet attrs, int defStyle) {
super(context, attrs, defStyle);
}
@Override
public boolean onInterceptTouchEvent(MotionEvent ev) {
final int action = ev.getAction();
switch (action)
{
case MotionEvent.ACTION_DOWN:
Log.i("VerticalScrollview", "onInterceptTouchEvent: DOWN super false" );
super.onTouchEvent(ev);
break;
case MotionEvent.ACTION_MOVE:
return false; // redirect MotionEvents to ourself
case MotionEvent.ACTION_CANCEL:
Log.i("VerticalScrollview", "onInterceptTouchEvent: CANCEL super false" );
super.onTouchEvent(ev);
break;
case MotionEvent.ACTION_UP:
Log.i("VerticalScrollview", "onInterceptTouchEvent: UP super false" );
return false;
default: Log.i("VerticalScrollview", "onInterceptTouchEvent: " + action ); break;
}
return false;
}
@Override
public boolean onTouchEvent(MotionEvent ev) {
super.onTouchEvent(ev);
Log.i("VerticalScrollview", "onTouchEvent. action: " + ev.getAction() );
return true;
}
}
在很多情况下,在ScrollView中有ListView是很有意义的。
下面是基于DougW建议的代码…工作在一个片段,占用较少的内存。
public static void setListViewHeightBasedOnChildren(ListView listView) {
ListAdapter listAdapter = listView.getAdapter();
if (listAdapter == null) {
return;
}
int desiredWidth = MeasureSpec.makeMeasureSpec(listView.getWidth(), MeasureSpec.AT_MOST);
int totalHeight = 0;
View view = null;
for (int i = 0; i < listAdapter.getCount(); i++) {
view = listAdapter.getView(i, view, listView);
if (i == 0) {
view.setLayoutParams(new ViewGroup.LayoutParams(desiredWidth, LayoutParams.WRAP_CONTENT));
}
view.measure(desiredWidth, MeasureSpec.UNSPECIFIED);
totalHeight += view.getMeasuredHeight();
}
ViewGroup.LayoutParams params = listView.getLayoutParams();
params.height = totalHeight + (listView.getDividerHeight() * (listAdapter.getCount() - 1));
listView.setLayoutParams(params);
listView.requestLayout();
}
在每个嵌入的列表视图上调用setListViewHeightBasedOnChildren(listview)。
我使用的一个解决方案是,添加ScrollView的所有内容(应该在listView的上面和下面)作为listView中的headerView和footerView。
它的工作原理是,convertview按它应该的方式重新使用。
这是我的解决方案。我对Android平台相当陌生,我确信这有点笨拙,特别是在直接调用.measure和设置LayoutParams的部分。直接使用Height属性,但它是有效的。
你所要做的就是调用Utility.setListViewHeightBasedOnChildren(yourListView),它将被调整大小,以完全适应其项目的高度。
public class Utility {
public static void setListViewHeightBasedOnChildren(ListView listView) {
ListAdapter listAdapter = listView.getAdapter();
if (listAdapter == null) {
// pre-condition
return;
}
int totalHeight = listView.getPaddingTop() + listView.getPaddingBottom();
for (int i = 0; i < listAdapter.getCount(); i++) {
View listItem = listAdapter.getView(i, null, listView);
if (listItem instanceof ViewGroup) {
listItem.setLayoutParams(new LayoutParams(LayoutParams.WRAP_CONTENT, LayoutParams.WRAP_CONTENT));
}
listItem.measure(0, 0);
totalHeight += listItem.getMeasuredHeight();
}
ViewGroup.LayoutParams params = listView.getLayoutParams();
params.height = totalHeight + (listView.getDividerHeight() * (listAdapter.getCount() - 1));
listView.setLayoutParams(params);
}
}
我把@DougW的实用程序转换成c#(在Xamarin中使用)。下面的代码对于列表中固定高度的项目很有效,如果只有一些项目比标准项目稍大一点,那么大多数项目都将很好,或者至少是一个良好的开端。
// You will need to put this Utility class into a code file including various
// libraries, I found that I needed at least System, Linq, Android.Views and
// Android.Widget.
using System;
using System.Linq;
using Android.Views;
using Android.Widget;
namespace UtilityNamespace // whatever you like, obviously!
{
public class Utility
{
public static void setListViewHeightBasedOnChildren (ListView listView)
{
if (listView.Adapter == null) {
// pre-condition
return;
}
int totalHeight = listView.PaddingTop + listView.PaddingBottom;
for (int i = 0; i < listView.Count; i++) {
View listItem = listView.Adapter.GetView (i, null, listView);
if (listItem.GetType () == typeof(ViewGroup)) {
listItem.LayoutParameters = new LinearLayout.LayoutParams (ViewGroup.LayoutParams.MatchParent, ViewGroup.LayoutParams.WrapContent);
}
listItem.Measure (0, 0);
totalHeight += listItem.MeasuredHeight;
}
listView.LayoutParameters.Height = totalHeight + (listView.DividerHeight * (listView.Count - 1));
}
}
}
谢谢@DougW,当我不得不使用其他人的代码时,这让我摆脱了困境。: -)