我的horizontallistview不滚动帮助我请我得到我以前的帖子How to load dynamic images in custom ListView的解决方案这个HorizontalListView类将显示图像但问题是不滚动如果我添加3个图像只有1＆amp; half显示我如何添加scrol查看此代码请帮助我。每件事都很好，只有水平列表视图不滚动
import android.content.Context;
import android.database.DataSetObserver;
import android.graphics.Rect;
import android.util.AttributeSet;
import android.util.Log;
import android.view.GestureDetector;
import android.view.GestureDetector.OnGestureListener;
import android.view.MotionEvent;
import android.view.View;
import android.view.View.OnTouchListener;
import android.widget.AdapterView;
import android.widget.ListAdapter;
import android.widget.Scroller;
public class HorizontalListView extends AdapterView<ListAdapter> {
public boolean mAlwaysOverrideTouch = true;
protected ListAdapter mAdapter;
private int mLeftViewIndex = -1;
private int mRightViewIndex = 0;
protected int mCurrentX;
protected int mNextX;
private int mMaxX = Integer.MAX_VALUE;
private int mDisplayOffset = 0;
protected Scroller mScroller;
private GestureDetector mGesture;
private Queue<View> mRemovedViewQueue = new LinkedList<View>();
private OnItemSelectedListener mOnItemSelected;
private OnItemClickListener mOnItemClicked;
private OnItemLongClickListener mOnItemLongClicked;
private boolean mDataChanged = false;
private boolean mMeasureHeightForVisibleOnly = true;
public HorizontalListView(Context context, AttributeSet attrs) {
super(context, attrs);
initView();
}
private synchronized void initView() {
mLeftViewIndex = -1;
mRightViewIndex = 0;
mDisplayOffset = 0;
mCurrentX = 0;
mNextX = 0;
mMaxX = Integer.MAX_VALUE;
mScroller = new Scroller(getContext());
mGesture = new GestureDetector(getContext(), mOnGesture);
}
@Override
public void setOnItemSelectedListener(AdapterView.OnItemSelectedListener listener) {
mOnItemSelected = listener;
}
@Override
public void setOnItemClickListener(AdapterView.OnItemClickListener listener){
mOnItemClicked = listener;
}
@Override
public void setOnItemLongClickListener(AdapterView.OnItemLongClickListener listener) {
mOnItemLongClicked = listener;
}
private DataSetObserver mDataObserver = new DataSetObserver() {
@Override
public void onChanged() {
synchronized(HorizontalListView.this){
mDataChanged = true;
}
invalidate();
requestLayout();
}
@Override
public void onInvalidated() {
reset();
invalidate();
requestLayout();
}
};
@Override
public ListAdapter getAdapter() {
return mAdapter;
}
@Override
public View getSelectedView() {
//TODO: implement
return null;
}
@Override
public void setAdapter(ListAdapter adapter) {
if(mAdapter != null) {
mAdapter.unregisterDataSetObserver(mDataObserver);
}
mAdapter = adapter;
mAdapter.registerDataSetObserver(mDataObserver);
reset();
}
/**
* @param visibleOnly - If set to true, then height is calculated
* only using visible views. If set to false then height is
* calculated using _all_ views in adapter. Default is true.
* Be very careful when passing false, as this may result in
* significant performance hit for larger number of views.
*/
public void setHeightMeasureMode(boolean visibleOnly) {
if(mMeasureHeightForVisibleOnly != visibleOnly) {
mMeasureHeightForVisibleOnly = visibleOnly;
requestLayout();
}
}
private synchronized void reset(){
initView();
removeAllViewsInLayout();
requestLayout();
}
@Override
public void setSelection(int position) {
//TODO: implement
}
private void addAndMeasureChild(final View child, int viewPos) {
LayoutParams params = child.getLayoutParams();
if(params == null) {
params = new LayoutParams(LayoutParams.FILL_PARENT, LayoutParams.FILL_PARENT);
}
addViewInLayout(child, viewPos, params, true);
child.measure(MeasureSpec.makeMeasureSpec(getWidth(), MeasureSpec.AT_MOST),
MeasureSpec.makeMeasureSpec(getHeight(), MeasureSpec.AT_MOST));
}
@Override
protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {
super.onMeasure(widthMeasureSpec, heightMeasureSpec);
if(MeasureSpec.getMode(heightMeasureSpec) != MeasureSpec.EXACTLY) {
int height = 0;
if(mMeasureHeightForVisibleOnly) {
int childCount = getChildCount();
for(int i = 0; i < childCount; i++) {
View v = getChildAt(i);
v.measure(MeasureSpec.UNSPECIFIED, MeasureSpec.UNSPECIFIED);
if(v.getMeasuredHeight() > height) {
height = v.getMeasuredHeight();
}
}
} else {
/* Traverses _all_ views! Bypasses view recycler! */
HashMap<Integer, View> mRecycler = new HashMap<Integer, View>();
int childCount = getAdapter().getCount();
for(int i = 0; i < childCount; i++) {
int type = getAdapter().getItemViewType(i);
View convertView = mRecycler.get(type);
View v = getAdapter().getView(i, convertView, this);
mRecycler.put(type, v);
v.measure(MeasureSpec.UNSPECIFIED, MeasureSpec.UNSPECIFIED);
if(v.getMeasuredHeight() > height) {
height = v.getMeasuredHeight();
}
}
}
if(MeasureSpec.getMode(heightMeasureSpec) == MeasureSpec.AT_MOST) {
int maxHeight = MeasureSpec.getSize(heightMeasureSpec);
if(maxHeight < height) {
height = maxHeight;
}
}
setMeasuredDimension(getMeasuredWidth(), height);
}
}
@Override
protected synchronized void onLayout(boolean changed, int left, int top,
int right, int bottom) {
super.onLayout(changed, left, top, right, bottom);
if(mAdapter == null){
return;
}
if(mDataChanged){
int oldCurrentX = mCurrentX;
initView();
removeAllViewsInLayout();
mNextX = oldCurrentX;
mDataChanged = false;
}
if(mScroller.computeScrollOffset()){
int scrollx = mScroller.getCurrX();
mNextX = scrollx;
}
if(mNextX <= 0){
mNextX = 0;
mScroller.forceFinished(true);
}
if(mNextX >= mMaxX) {
mNextX = mMaxX;
mScroller.forceFinished(true);
}
int dx = mCurrentX - mNextX;
removeNonVisibleItems(dx);
fillList(dx);
positionItems(dx);
mCurrentX = mNextX;
if(!mScroller.isFinished()){
post(new Runnable(){
public void run() {
requestLayout();
}
});
}
}
private void fillList(final int dx) {
int edge = 0;
View child = getChildAt(getChildCount()-1);
if(child != null) {
edge = child.getRight();
}
fillListRight(edge, dx);
edge = 0;
child = getChildAt(0);
if(child != null) {
edge = child.getLeft();
}
fillListLeft(edge, dx);
}
private void fillListRight(int rightEdge, final int dx) {
while(rightEdge + dx < getWidth() && mRightViewIndex < mAdapter.getCount()) {
View child = mAdapter.getView(mRightViewIndex, mRemovedViewQueue.poll(), this);
addAndMeasureChild(child, -1);
rightEdge += child.getMeasuredWidth();
if(mRightViewIndex == mAdapter.getCount()-1) {
mMaxX = mCurrentX + rightEdge - getWidth();
}
if (mMaxX < 0) {
mMaxX = 0;
}
mRightViewIndex++;
}
}
private void fillListLeft(int leftEdge, final int dx) {
while(leftEdge + dx > 0 && mLeftViewIndex >= 0) {
View child = mAdapter.getView(mLeftViewIndex, mRemovedViewQueue.poll(), this);
addAndMeasureChild(child, 0);
leftEdge -= child.getMeasuredWidth();
mLeftViewIndex--;
mDisplayOffset -= child.getMeasuredWidth();
}
}
private void removeNonVisibleItems(final int dx) {
View child = getChildAt(0);
while(child != null && child.getRight() + dx <= 0) {
mDisplayOffset += child.getMeasuredWidth();
mRemovedViewQueue.offer(child);
removeViewInLayout(child);
mLeftViewIndex++;
child = getChildAt(0);
}
child = getChildAt(getChildCount()-1);
while(child != null && child.getLeft() + dx >= getWidth()) {
mRemovedViewQueue.offer(child);
removeViewInLayout(child);
mRightViewIndex--;
child = getChildAt(getChildCount()-1);
}
}
private void positionItems(final int dx) {
if(getChildCount() > 0){
mDisplayOffset += dx;
int left = mDisplayOffset;
for(int i=0;i<getChildCount();i++){
View child = getChildAt(i);
int childWidth = child.getMeasuredWidth();
child.layout(left, 0, left + childWidth, child.getMeasuredHeight());
left += childWidth;
}
}
}
public synchronized void scrollTo(int x) {
mScroller.startScroll(mNextX, 0, x - mNextX, 0);
requestLayout();
}
@Override
public boolean dispatchTouchEvent(MotionEvent ev) {
boolean handled = super.dispatchTouchEvent(ev);
handled |= mGesture.onTouchEvent(ev);
return handled;
}
protected boolean onFling(MotionEvent e1, MotionEvent e2, float velocityX,
float velocityY) {
synchronized(HorizontalListView.this){
mScroller.fling(mNextX, 0, (int)-velocityX, 0, 0, mMaxX, 0, 0);
}
requestLayout();
return true;
}
protected boolean onDown(MotionEvent e) {
mScroller.forceFinished(true);
return true;
}
private OnGestureListener mOnGesture = new GestureDetector.SimpleOnGestureListener() {
@Override
public boolean onDown(MotionEvent e) {
return HorizontalListView.this.onDown(e);
}
@Override
public boolean onFling(MotionEvent e1, MotionEvent e2, float velocityX,
float velocityY) {
return HorizontalListView.this.onFling(e1, e2, velocityX, velocityY);
}
@Override
public boolean onScroll(MotionEvent e1, MotionEvent e2,
float distanceX, float distanceY) {
synchronized(HorizontalListView.this){
mNextX += (int)distanceX;
}
requestLayout();
return true;
}
@Override
public boolean onSingleTapConfirmed(MotionEvent e) {
Rect viewRect = new Rect();
for(int i=0;i<getChildCount();i++){
View child = getChildAt(i);
int left = child.getLeft();
int right = child.getRight();
int top = child.getTop();
int bottom = child.getBottom();
viewRect.set(left, top, right, bottom);
if(viewRect.contains((int)e.getX(), (int)e.getY())){
if(mOnItemClicked != null){
mOnItemClicked.onItemClick(HorizontalListView.this, child, mLeftViewIndex + 1 + i, mAdapter.getItemId( mLeftViewIndex + 1 + i ));
}
if(mOnItemSelected != null){
mOnItemSelected.onItemSelected(HorizontalListView.this, child, mLeftViewIndex + 1 + i, mAdapter.getItemId( mLeftViewIndex + 1 + i ));
}
break;
}
}
return true;
}
@Override
public void onLongPress(MotionEvent e) {
Rect viewRect = new Rect();
int childCount = getChildCount();
for (int i = 0; i < childCount; i++) {
View child = getChildAt(i);
int left = child.getLeft();
int right = child.getRight();
int top = child.getTop();
int bottom = child.getBottom();
viewRect.set(left, top, right, bottom);
if (viewRect.contains((int) e.getX(), (int) e.getY())) {
if (mOnItemLongClicked != null) {
mOnItemLongClicked.onItemLongClick(HorizontalListView.this, child, mLeftViewIndex + 1 + i, mAdapter.getItemId(mLeftViewIndex + 1 + i));
}
break;
}
}
}
};
}
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout
xmlns:android="http://schemas.android.com/apk/res/android"
android:orientation="vertical"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
>
<ImageView
android:id="@+id/image"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:background="#fff"
android:src="@drawable/icon"
/>
<TextView
android:id="@+id/title"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:textColor="#000"
android:gravity="center_horizontal"
/>
</LinearLayout>
<com.schoollunchapp.HorizontalListView
android:id="@+id/listview"
android:layout_width="wrap_content"
android:layout_height="0dp"
android:layout_weight="0.6"
android:background="#EEEEEE">
</com.schoollunchapp.HorizontalListView>
答案 0 :(得分：1)
@Override
public boolean dispatchTouchEvent(MotionEvent ev) {
boolean handled = super.dispatchTouchEvent(ev);
handled |= mGesture.onTouchEvent(ev); //this is always true during scrolling
return handled; //returning true will stop the listview functions to scroll it
}
@Override
public boolean onScroll(MotionEvent e1, MotionEvent e2,
float distanceX, float distanceY) {
synchronized(HorizontalListView.this){
mNextX += (int)distanceX;
}
requestLayout();
return true;
}
以上代码是问题
据我所知，如果你在dispatchTouchEvent函数中返回true，listview将不会滚动，在你的情况下滚动时总是如此。 onScroll手势总是返回true，listview永远不会滚动。
您正尝试手动执行滚动操作。 尝试返回false并且不要手动处理滚动。
我无法阅读您的完整代码，因为它太长了，但我已经发现了您的问题，现在您可以按照您想要的任何方式处理它。