Android 使用HorizontalListView 实现图片底部轮播（带源码）

一,主页

public class MainActivity extends Activity {
private HorizontalListView listView ;
private MyAdapter mAdapter ;

private List<Map<String, Object>> list ;
private Map<String,Object> map ;

@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
initView();

listView.setOnItemClickListener(new OnItemClickListener() {
@Override
public void onItemClick(AdapterView<?> arg0, View arg1, int arg2,
long arg3) {

Toast.makeText(MainActivity.this, "你点击的是第"+(arg2+1)+"张图片", Toast.LENGTH_SHORT).show();
}
});
listView.setOnItemSelectedListener(new OnItemSelectedListener() {

@Override
public void onItemSelected(AdapterView<?> arg0, View arg1,
int arg2, long arg3) {

}

@Override
public void onNothingSelected(AdapterView<?> arg0) {
// TODO Auto-generated method stub

}
});
}

//	private int a=688;
private int b=-200;
private int c;
private int a;
private void initView() {
listView = (HorizontalListView) findViewById(R.id.listView);

list = this.getData();
a = (int) listView.getScaleX();
mAdapter = new MyAdapter(MainActivity.this, list);
listView.setAdapter(mAdapter);
listView.scrollTo((int)a);

Log.i("INFO", listView.getScaleX()+"距离");
Toast.makeText(MainActivity.this, "距离"+listView.getScaleX(), Toast.LENGTH_LONG);
}

public void left(View v){
c=a+b;
listView.scrollTo(c);
a=c; //288
b=-200;

}

private List<Map<String, Object>> getData(){

int [] pic = {R.drawable.a,R.drawable.b,R.drawable.c,R.drawable.d,R.drawable.e,
R.drawable.f,R.drawable.g,R.drawable.h,R.drawable.i,R.drawable.j};

list = new ArrayList<Map<String,Object>>();

for(int i = 0;i<pic.length;i++){
map =new HashMap<String, Object>();
map.put("page", "第"+(i+1)+"张");
map.put("pic", pic[i]);
list.add(map);
}
return list;

}

二：适配器

public class MyAdapter extends BaseAdapter {

private Context mContext ;
private List<Map<String,Object>> mList;

public MyAdapter(Context context ,List<Map<String,Object>> list){
this.mContext = context;
this.mList = list;
}

@Override
public int getCount() {
return mList.size();
}

@Override
public Object getItem(int position) {
return mList.get(position);
}

@Override
public long getItemId(int position) {
return position;
}

@Override
public View getView(int position, View convertView, ViewGroup parent) {
HolderView holderView = null;
View view  = convertView;

if(view == null ){
holderView = new HolderView();
view = LayoutInflater.from(mContext).inflate(R.layout.match_league_round_item, parent, false);

holderView.imageView =(ImageView) view.findViewById(R.id.imageView);
holderView.textView = (TextView) view.findViewById(R.id.textView);

view.setTag(holderView);
}else{
holderView = (HolderView) view.getTag();
}

holderView.imageView.setImageResource((Integer) mList.get(position).get("pic"));
holderView.textView.setText((String) mList.get(position).get("page"));

return view;
}

class HolderView{
ImageView imageView;
TextView textView;
}

三:控件类

public class HorizontalListView extends AdapterView<ListAdapter> {
<span style="font-size:14px;">
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;

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();
}

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 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(){
@Override
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 + child.getPaddingRight();
}
}
}

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) {
for(int i=0;i<getChildCount();i++){
View child = getChildAt(i);
if (isEventWithinView(e, child)) {
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) {
int childCount = getChildCount();
for (int i = 0; i < childCount; i++) {
View child = getChildAt(i);
if (isEventWithinView(e, child)) {
if (mOnItemLongClicked != null) {
mOnItemLongClicked.onItemLongClick(HorizontalListView.this, child, mLeftViewIndex + 1 + i, mAdapter.getItemId(mLeftViewIndex + 1 + i));
}
break;
}

}
}

private boolean isEventWithinView(MotionEvent e, View child) {
Rect viewRect = new Rect();
int[] childPosition = new int[2];
child.getLocationOnScreen(childPosition);
int left = childPosition[0];
int right = left + child.getWidth();
int top = childPosition[1];
int bottom = top + child.getHeight();
viewRect.set(left, top, right, bottom);
return viewRect.contains((int) e.getRawX(), (int) e.getRawY());
}
};

}  </span>