我有一个android布局，其中有一个带有许多元素的scrollView。在scrollView的底部，我有一个listView，然后由适配器填充。
我遇到的问题是，android是排除listView从scrollView作为scrollView已经有一个可滚动的功能。我希望listView和内容一样长，并且主滚动视图是可滚动的。
我怎样才能实现这种行为呢?
这是我的主要布局:
<ScrollView
android:id="@+id/scrollView1"
android:layout_width="match_parent"
android:layout_height="0dp"
android:layout_weight="2"
android:fillViewport="true"
android:gravity="top" >
<LinearLayout
android:id="@+id/foodItemActvity_linearLayout_fragments"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:orientation="vertical" >
</LinearLayout>
</ScrollView>
然后，我以编程方式将我的组件添加到linearlayour的id: foodItemActvity_linearLayout_fragments。下面是加载到线性布局中的一个视图。就是这个给我的卷轴带来了麻烦。
<?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:id="@+id/fragment_dds_review_textView_label"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="Reviews:"
android:textAppearance="?android:attr/textAppearanceMedium" />
<ListView
android:id="@+id/fragment_dds_review_listView"
android:layout_width="match_parent"
android:layout_height="wrap_content">
</ListView>
</LinearLayout>
我的适配器然后填充这个列表视图。
当我点击主scrollView时，这是一个来自android层级查看器的图像:
如您所见，它排除了评论列表视图。
我应该能够向下滚动页面，看到8个评论，但它只显示了这3个，我可以滚动评论所在的一小部分。我想要一个全局页面滚动
好吧，这是我的答案。固定ListView高度的方法足够封闭，但并不完美。如果大多数项目都是相同的高度，那工作得很好。但如果不是，那就有大问题了。我尝试了很多次，当我输出listItem的值时。getMeasureHeight和listItem。getMeasuerWidth到日志中，我看到宽度值变化很大，这在这里是不期望的，因为同一ListView中的所有项应该具有相同的宽度。问题来了:
有些人使用度量(0,0)，这实际上使视图在两个方向上都没有边界，宽度也失控了。有些人尝试获取listView的twidth，但它返回0，没有意义。
当我进一步了解android如何渲染视图时，我意识到所有这些尝试都无法达到我搜索的答案，除非这些函数在视图渲染后运行。
这一次我使用getViewTreeObserver在ListView上，我想固定高度，然后添加ongloballayoutlistener。在这个方法中，我声明了一个新的OnGlobalLayoutListener，在这个方法中，getWidth返回ListView的实际宽度。
private void getLayoutWidth(final ListView lv, final int pad){
//final ArrayList<Integer> width = new ArrayList<Integer>();
ViewTreeObserver vto = lv.getViewTreeObserver();
vto.addOnGlobalLayoutListener(new ViewTreeObserver.OnGlobalLayoutListener() {
@Override
public void onGlobalLayout() {
lv.getViewTreeObserver().removeOnGlobalLayoutListener(this);
//width.add(layout.getMeasuredWidth());
int width = lv.getMeasuredWidth();
ListUtils.setDynamicHeight(lv, width, pad);
}
});
}
public static class ListUtils {
//private static final int UNBOUNDED = View.MeasureSpec.makeMeasureSpec(0, View.MeasureSpec.UNSPECIFIED);
public static void setDynamicHeight(ListView mListView, int width, int pad) {
ListAdapter mListAdapter = mListView.getAdapter();
mListView.getParent();
if (mListAdapter == null) {
// when adapter is null
return;
}
int height = 0;
int desiredWidth = View.MeasureSpec.makeMeasureSpec(width - 2*pad, View.MeasureSpec.EXACTLY);
for (int i = 0; i < mListAdapter.getCount(); i++) {
View listItem = mListAdapter.getView(i, null, mListView);
listItem.measure(desiredWidth, View.MeasureSpec.UNSPECIFIED);
//listItem.measure(UNBOUNDED, UNBOUNDED);
height += listItem.getMeasuredHeight() + 2*pad;
Log.v("ViewHeight :", mListAdapter.getClass().toString() + " " + listItem.getMeasuredHeight() + "--" + listItem.getMeasuredWidth());
}
ViewGroup.LayoutParams params = mListView.getLayoutParams();
params.height = height + (mListView.getDividerHeight() * (mListAdapter.getCount() - 1));
mListView.setLayoutParams(params);
mListView.requestLayout();
}
}
value pad，是我在ListView layout中设置的填充。
在xml:
<com.example.util.NestedListView
android:layout_marginTop="10dp"
android:id="@+id/listview"
android:layout_width="fill_parent"
android:layout_height="fill_parent"
android:divider="@null"
android:layout_below="@+id/rl_delivery_type" >
</com.example.util.NestedListView>
在Java中:
public class NestedListView extends ListView implements View.OnTouchListener, AbsListView.OnScrollListener {
private int listViewTouchAction;
private static final int MAXIMUM_LIST_ITEMS_VIEWABLE = 99;
public NestedListView(Context context, AttributeSet attrs) {
super(context, attrs);
listViewTouchAction = -1;
setOnScrollListener(this);
setOnTouchListener(this);
}
@Override
public 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);
}
}
}
@Override
public void onScrollStateChanged(AbsListView view, int scrollState) {
}
@Override
protected 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 instance
if (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);
}
@Override
public 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;
}
}
正如其他人已经提到的，不要在ScrollView中使用ListView。
为了解决问题，你可以使用LinearLayout，但仍然要保持整洁-用适配器填充你的LinearLayout，就像你用ListView做的一样
您可以使用这个类作为支持适配器的线性布局替代品
import android.content.Context;
import android.database.DataSetObserver;
import android.util.AttributeSet;
import android.view.View;
import android.view.ViewGroup;
import android.widget.BaseAdapter;
import android.widget.LinearLayout;
public class AdaptableLinearLayout extends LinearLayout {
private BaseAdapter mAdapter;
private int mItemCount = 0;
private boolean mDisableChildrenWhenDisabled = false;
private int mWidthMeasureSpec;
private int mHeightMeasureSpec;
public AdaptableLinearLayout(Context context, AttributeSet attrs) {
super(context, attrs);
// TODO Auto-generated constructor stub
}
public BaseAdapter getAdapter() {
return mAdapter;
}
public void setAdapter(BaseAdapter adapter) {
mAdapter = adapter;
adapter.registerDataSetObserver(new DataSetObserver() {
@Override
public void onChanged() {
updateLayout();
super.onChanged();
}
@Override
public void onInvalidated() {
updateLayout();
super.onInvalidated();
}
});
updateLayout();
}
private void updateLayout() {
mItemCount = mAdapter.getCount();
requestLayout();
invalidate();
}
/**
* set size for the current View
*/
@Override
protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {
super.onMeasure(widthMeasureSpec, heightMeasureSpec);
mWidthMeasureSpec = widthMeasureSpec;
mHeightMeasureSpec = heightMeasureSpec;
removeAllViewsInLayout();
for (int i = 0; i < mItemCount; i++) {
makeAndAddView(i);
}
}
private View makeAndAddView(int position) {
View child;
// Nothing found in the recycler -- ask the adapter for a view
child = mAdapter.getView(position, null, this);
// Position the view
setUpChild(child, position);
return child;
}
private void setUpChild(View child, int position) {
ViewGroup.LayoutParams lp = child.getLayoutParams();
if (lp == null) {
lp = generateDefaultLayoutParams();
}
addViewInLayout(child, position, lp);
// Get measure specs
int childHeightSpec = ViewGroup.getChildMeasureSpec(mHeightMeasureSpec, getPaddingTop() + getPaddingBottom(), lp.height);
int childWidthSpec = ViewGroup.getChildMeasureSpec(mWidthMeasureSpec, getPaddingLeft() + getPaddingRight(), lp.width);
// Measure child
child.measure(childWidthSpec, childHeightSpec);
int childLeft;
int childRight;
// Position vertically based on gravity setting
int childTop = getPaddingTop() + ((getMeasuredHeight() - getPaddingBottom() - getPaddingTop() - child.getMeasuredHeight()) / 2);
int childBottom = childTop + child.getMeasuredHeight();
int width = child.getMeasuredWidth();
childLeft = 0;
childRight = childLeft + width;
child.layout(childLeft, childTop, childRight, childBottom);
if (mDisableChildrenWhenDisabled) {
child.setEnabled(isEnabled());
}
}
}
