自定义HorizontalScrollView

对图片底部布局activity_index_gallery-item

<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:orientation="vertical" android:layout_width="120dp"
android:background="@android:color/white"
android:layout_height="120dp">
<ImageView
android:id="@+id/index_gallery_item_image"
android:layout_width="80dp"
android:layout_height="80dp"
android:layout_alignParentTop="true"
android:layout_centerHorizontal="true"
android:layout_margin="5dp"
android:scaleType="centerCrop"
/>
<TextView
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:id="@+id/index_gallery_item_text"
android:layout_centerHorizontal="true"
android:layout_below="@id/index_gallery_item_image"
android:layout_marginBottom="5dp"
android:layout_marginTop="5dp"
android:textColor="#ff0000"
android:textSize="12dp"
/>
</RelativeLayout>

HorizontalScrollViewAdapter

public class HorizontalScrollViewAdapter {
private Context mContext;
private LayoutInflater mInflater;
private List<Integer> mDatas;

public HorizontalScrollViewAdapter(Context context,List<Integer> mDatas){
this.mContext = context;
mInflater = LayoutInflater.from(context);
this.mDatas = mDatas;
}

public int getCount(){
return  mDatas.size();
}

public Object getItem(int position){
return mDatas.get(position);
}

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

public View getView(int position,View convertView,ViewGroup parent){
ViewHolder viewHolder = null;
if(convertView == null){
viewHolder = new ViewHolder();
convertView = mInflater.inflate(R.layout.activity_index_gallery_item,parent,false);
viewHolder.mImg = (ImageView) convertView.findViewById(R.id.index_gallery_item_image);
viewHolder.mText = (TextView) convertView.findViewById(R.id.index_gallery_item_text);

convertView.setTag(viewHolder);
}else {
viewHolder = (ViewHolder) convertView.getTag();
}
viewHolder.mImg.setImageResource(mDatas.get(position));
viewHolder.mText.setText("some info");

return convertView;
}

private class ViewHolder{
ImageView mImg;
TextView mText;
}

}

activity_main2

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:background="@android:color/white"
android:orientation="vertical"
tools:context="com.example.administrator.testapplication.Main2Activity">
<FrameLayout
android:layout_width="match_parent"
android:layout_height="0dp"
android:layout_weight="1">
<ImageView
android:id="@+id/id_content"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:layout_gravity="center"
android:layout_margin="10dp"
android:scaleType="centerCrop"
android:src="@mipmap/ic_launcher"
/>
</FrameLayout>
<com.example.administrator.testapplication.MyHorizontalScrollView
android:id="@+id/id_horizontalScrollView"
android:layout_width="wrap_content"
android:layout_height="150dp"
android:layout_gravity="bottom"
android:background="@android:color/white"
android:scrollbars="none" >

<LinearLayout
android:id="@+id/id_gallery"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_gravity="center_vertical"
android:orientation="horizontal" >
</LinearLayout>

</com.example.administrator.testapplication.MyHorizontalScrollView>
</LinearLayout>

MyHorizontalScrollView

public class MyHorizontalScrollView extends HorizontalScrollView implements View.OnClickListener {

/**
* 图片滚动时的回调接口
*/
public interface  CurrentImageChangeListener{
void onCurrentImgChanged(int position,View viewIndicator);
}

public interface  OnItemClickListener{
void onClick(View view,int pos);
}

private CurrentImageChangeListener mListener;

private OnItemClickListener mOnClickListener;

/**
* HorizontalListView中的LinearLayout
*/
private LinearLayout mContainer;

private int mChildWidth,mChildHeight;//子元素的宽度.高度

private int mCurrentIndex,mFirstIndex;//当前最后一张图片的index，当前第一张图片的下标

private View mFirstView;//当前第一个View

private HorizontalScrollViewAdapter mAdapter;//数据适配器

private int mCountOneScreen;//每个屏幕最多显示的个数

private int mScreenWidth;//屏幕的宽度

private Map<View,Integer>mViewPos = new HashMap<View,Integer>();

public MyHorizontalScrollView(Context context, AttributeSet attrs) {
super(context, attrs);
//获得屏幕宽度
WindowManager wm = (WindowManager) context.getSystemService(Context.WINDOW_SERVICE);
DisplayMetrics outMetrics = new DisplayMetrics();
wm.getDefaultDisplay().getMetrics(outMetrics);
mScreenWidth = outMetrics.widthPixels;
}

@Override
protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {
super.onMeasure(widthMeasureSpec, heightMeasureSpec);
mContainer = (LinearLayout) getChildAt(0);
}

/**
* 加载下一张图片
*/
protected  void loadNextImg(){
//数组边界值计算
if(mCurrentIndex == mAdapter.getCount() - 1){
return;
}
//移除第一张图片，并且将水平滚动位置置0
scrollTo(0,0);
mViewPos.remove(mContainer.getChildAt(0));
mContainer.removeViewAt(0);

//获取下一张图片，并且设置onclick事件，且加入容器中
View view = mAdapter.getView(++mCurrentIndex,null,mContainer);
view.setOnClickListener(this);
mContainer.addView(view);
mViewPos.put(view,mCurrentIndex);

//当前第一张图片小标
mFirstIndex++;
//如果设置了滚动监听则触发
if(mListener != null){
notifyCurrentImgChanged();

}
}

/**
* 加载前一张图片
*/
protected void loadPreImg(){
//如果当前已经是第一张，则返回
if(mFirstIndex == 0){
return;
}
//获得当前应该显示为第一张图片的下标
int index = mCurrentIndex - mCountOneScreen;
if(index >= 0){
//移除最后一张
int oldViewPos = mContainer.getChildCount()-1;
mViewPos.remove(mContainer.getChildAt(oldViewPos));
mContainer.removeViewAt(oldViewPos);

//将此View放入第一个位置
View view = mAdapter.getView(index,null,mContainer);
mViewPos.put(view,index);
mContainer.addView(view,0);
view.setOnClickListener(this);
//水平滚动位置向左移动view的宽度像素
scrollTo(mChildWidth,0);
//当前位置--，当前第一个显示的下标--
mCurrentIndex--;
mFirstIndex--;
//回调
if(mListener != null){
notifyCurrentImgChanged();
}
}

}

/**
* 滑动时的回调
*/
private void notifyCurrentImgChanged() {
//先清除所有的背景色，点击时会设置为蓝色
for (int i = 0; i < mContainer.getChildCount(); i++) {
mContainer.getChildAt(i).setBackgroundColor(Color.WHITE);
}
mListener.onCurrentImgChanged(mFirstIndex,mContainer.getChildAt(0));
}

/**
*
* 初始化数据，设置数据适配器
* @param mAdapter
*/
public void initDatas(HorizontalScrollViewAdapter mAdapter){
this.mAdapter = mAdapter;
mContainer = (LinearLayout) getChildAt(0);

//获得适配器中第一个View
final View view = mAdapter.getView(0,null,mContainer);
mContainer.addView(view);

//强制计算当前的view的宽和高
if(mChildWidth == 0 && mChildHeight == 0){
int w = View.MeasureSpec.makeMeasureSpec(0, MeasureSpec.UNSPECIFIED);
int h = View.MeasureSpec.makeMeasureSpec(0,MeasureSpec.UNSPECIFIED);

view.measure(w,h);
mChildHeight = view.getMeasuredHeight();
mChildWidth = view.getMeasuredWidth();

//计算每次加载多少个View
//  mCountOneScreen = (mScreenWidth/mChildWidth == 0)?mScreenWidth/mChildWidth+1:mScreenWidth/mChildWidth+2;
mCountOneScreen = mScreenWidth / mChildWidth+2;
}
//初始化第一屏幕的元素
initFirstScreenChildren(mCountOneScreen);

}

/**
* 加载第一屏的view
* @param mCountOneScreen
*/
private void initFirstScreenChildren(int mCountOneScreen) {
mContainer = (LinearLayout) getChildAt(0);
mContainer.removeAllViews();
mViewPos.clear();
for (int i = 0; i < mCountOneScreen; i++) {
View view = mAdapter.getView(i,null,mContainer);
view.setOnClickListener(this);
mContainer.addView(view);
mViewPos.put(view,i);
mCurrentIndex = i;

}

if(mListener != null){
notifyCurrentImgChanged();
}
}

@Override
public boolean onTouchEvent(MotionEvent ev) {
switch (ev.getAction()){
case MotionEvent.ACTION_MOVE:
int scrollX = getScrollX();
//如果当前scrollX为view的宽度，加载下一张，移除第一张
if(scrollX >= mChildWidth){
loadNextImg();
}
//如果当前scrollX = 0，往前设置一张，移除最后一张
if(scrollX == 0){
loadPreImg();
}
break;
}
return super.onTouchEvent(ev);
}

@Override
public void onClick(View v) {
if(mOnClickListener != null){
for (int i = 0; i < mContainer.getChildCount(); i++) {
mContainer.getChildAt(i).setBackgroundColor(Color.WHITE);
}
mOnClickListener.onClick(v,mViewPos.get(v));

}

}

public void setOnItemClickListener(OnItemClickListener mOnClickListener){
this.mOnClickListener = mOnClickListener;
}
public void  setmCurrentImageChangeListener( CurrentImageChangeListener mListener){
this.mListener = mListener;
}

}

Main

public class Main2Activity extends Activity {
private MyHorizontalScrollView mHorizontalScrollView;
private HorizontalScrollViewAdapter mAdapter;
private ImageView mImg;
private List<Integer> mDatas = new ArrayList<>(Arrays.asList(R.mipmap.a,
R.mipmap.b,R.mipmap.c,R.mipmap.d,R.mipmap.e,R.mipmap.f,R.mipmap.g,
R.mipmap.h,R.mipmap.l));
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
requestWindowFeature(Window.FEATURE_NO_TITLE);
setContentView(R.layout.activity_main2);

mImg = (ImageView) findViewById(R.id.id_content);
mHorizontalScrollView = (MyHorizontalScrollView) findViewById(R.id.id_horizontalScrollView);
mAdapter = new HorizontalScrollViewAdapter(this,mDatas);
//添加回滚回调
mHorizontalScrollView.setmCurrentImageChangeListener(new MyHorizontalScrollView.CurrentImageChangeListener() {
@Override
public void onCurrentImgChanged(int position, View viewIndicator) {
mImg.setImageResource(mDatas.get(position));
viewIndicator.setBackgroundColor(Color.parseColor("#aa024da4"));
}
});

//添加点击回调
mHorizontalScrollView.setOnItemClickListener(new MyHorizontalScrollView.OnItemClickListener() {
@Override
public void onClick(View view, int pos) {
mImg.setImageResource(mDatas.get(pos));
view.setBackgroundColor(Color.parseColor("#aa024da4"));
}
});

//设置适配器
mHorizontalScrollView.initDatas(mAdapter);

}
}