Android使用HorizontalScrollView实现水平滚动

package com.crazy.horizontalscrollviewtest; import java.io.InputStream;import java.util.ArrayList;import java.util.Arrays;import java.util.List; import com.crazy.horizontalscrollviewtest.MyHorizontalView.CurrentImageChangeListener;import com.crazy.horizontalscrollviewtest.MyHorizontalView.OnItemClickListener; import android.content.Context;import android.graphics.Bitmap;import android.graphics.BitmapFactory;import android.graphics.Color;import android.os.Bundle;import android.util.Log;import android.view.View;import android.widget.ImageView;import android.support.v7.app.AppCompatActivity;  public class MainActivity extends AppCompatActivity {   private ImageView mImageView;  private MyHorizontalView myHorizontalView;  private List<Bitmap> bitmapList;  private MyAdapter adapter;   @Override  protected void onCreate(Bundle savedInstanceState) {    super.onCreate(savedInstanceState);    setContentView(R.layout.activity_main);     init();  }   private void init() {    mImageView = (ImageView)findViewById(R.id.imageView);     bitmapList = new ArrayList<>(Arrays.asList(        readBitMap(this, R.drawable.bricks),        readBitMap(this, R.drawable.dog),        readBitMap(this, R.drawable.flower),        readBitMap(this, R.drawable.grass),        readBitMap(this, R.drawable.stones),        readBitMap(this, R.drawable.wood),        readBitMap(this, R.drawable.bg_01),        readBitMap(this, R.drawable.bg_02),        readBitMap(this, R.drawable.bg_03),        readBitMap(this, R.drawable.bg_04),        readBitMap(this, R.drawable.bg_05),        readBitMap(this, R.drawable.bg_06),        readBitMap(this, R.drawable.bg_07)    ));     myHorizontalView = (MyHorizontalView)findViewById(R.id.my_horizontal);    adapter = new MyAdapter(this, bitmapList);     //设置适配器    myHorizontalView.initDatas(adapter);     //添加滚动回调    myHorizontalView        .setCurrentImageChangeListener(new CurrentImageChangeListener() {          @Override          public void onCurrentImgChanged(int position, View viewIndicator) {            Log.e("==============","===============  " + position);            mImageView.setImageBitmap(bitmapList.get(position));            viewIndicator.setBackgroundColor(Color.parseColor("#AA024DA4"));          }        });     //添加点击回调    myHorizontalView.setOnItemClickListener(new OnItemClickListener() {      @Override      public void onItemClick(View view, int position) {         mImageView.setImageBitmap(bitmapList.get(position));        view.setBackgroundColor(Color.parseColor("#AA024DA4"));      }    });  }   public static Bitmap readBitMap(Context mContext, int resId) {    BitmapFactory.Options opt = new BitmapFactory.Options();    opt.inPreferredConfig = Bitmap.Config.RGB_565;    opt.inPurgeable = true;    opt.inInputShareable = true;     InputStream is = mContext.getResources().openRawResource(resId);    return BitmapFactory.decodeStream(is, null, opt);  } }

package com.crazy.horizontalscrollviewtest; import java.util.ArrayList;import java.util.List; import android.content.Context;import android.graphics.Bitmap;import android.util.Log;import android.view.View;import android.view.ViewGroup;import android.widget.BaseAdapter;import android.widget.ImageView;import android.widget.RelativeLayout; /** * Created by antimage on 2016/1/9. */public class MyAdapter extends BaseAdapter {   private List<Bitmap> bitmapList;  private Context mContext;   public MyAdapter(Context context, List<Bitmap> bitmapList) {    mContext = context;    if (bitmapList == null) {      bitmapList = new ArrayList<Bitmap>();    } else {      this.bitmapList = bitmapList;    }  }   @Override  public int getCount() {    return bitmapList.size();  }   @Override  public Object getItem(int position) {    return bitmapList.get(position);  }   @Override  public long getItemId(int position) {    return position;  }   @Override  public View getView(int position, View convertView, ViewGroup parent) {     ViewHolder viewHolder = null;    View view = null;    // 此处要用相对布局，且与 XML 中的布局相同；    // 如果使用线性布局，则显示不完整    RelativeLayout layout;    if (convertView == null) {       layout = (RelativeLayout) View.inflate(mContext, R.layout.image_item_layout, null);       viewHolder = new ViewHolder();       viewHolder.image = (ImageView) layout.findViewById(R.id.top_image);      layout.setTag(viewHolder);    } else {      layout = (RelativeLayout) convertView;      view = layout;      viewHolder = (ViewHolder) layout.getTag();      Log.e("MyAdapter", "正在检测数据来了没有 ");    }    Bitmap btm = (Bitmap) getItem(position);    viewHolder.image.setImageBitmap(btm);     Log.e("MyAdapter", "信息来了哦！");     return layout;  }   private static class ViewHolder {    ImageView image;  } }

package com.crazy.horizontalscrollviewtest;  import java.util.HashMap;import java.util.Map; import android.app.Activity;import android.content.Context;import android.graphics.Color;import android.util.AttributeSet;import android.util.DisplayMetrics;import android.util.Log;import android.view.MotionEvent;import android.view.View;import android.view.ViewGroup;import android.widget.HorizontalScrollView; /** * Created by antimage on 2016/1/9. */public class MyHorizontalView extends HorizontalScrollView    implements View.OnClickListener {   private String TAG = "MyHorizontalView";   private ViewGroup parent;  private int screenWidth;  /* 当前最后一张图片的index*/  private int mCurrentIndex;  /* 当前第一张图片的下标*/  private int mFristIndex;  /* 每屏幕最多显示的个数*/  private int mCountOneScreen;  /* 子元素的宽度*/  private int mChildWidth;  /* 子元素的高度*/  private int mChildHeight;   private MyAdapter mAdapter;   private CurrentImageChangeListener mListener;   private OnItemClickListener mOnItemClickListener;   /**   * 图片滚动时的回调接口   */  public interface CurrentImageChangeListener {    void onCurrentImgChanged(int position, View viewIndicator);  }   /**   * 点击条目时的回调   */  public interface OnItemClickListener {    void onItemClick(View view, int pos);  }   /* 保存View与位置的键值对 */  private Map<View, Integer> mViewPos = new HashMap<>();   public MyHorizontalView(Context context) {    this(context, null);  }   public MyHorizontalView(Context context, AttributeSet attrs) {    this(context, attrs, 0);  }   public MyHorizontalView(Context context, AttributeSet attrs, int defStyleAttr) {    super(context, attrs, defStyleAttr);     this.setSmoothScrollingEnabled(true);     DisplayMetrics metrics = new DisplayMetrics();    // 取得窗口属性    ((Activity) context).getWindowManager().getDefaultDisplay().getMetrics(metrics);    // 窗口的宽度 （像素）    screenWidth = metrics.widthPixels;  }   /**   * 初始化数据，设置数据适配器   */  public void initDatas(MyAdapter mAdapter) {     if (getChildCount() == 0) {      Log.e(TAG, "必须要有子元素");    }    if (getChildCount() == 0 || mAdapter == null)      return;     this.mAdapter = mAdapter;    parent = (ViewGroup) getChildAt(0);     // 获得适配器中第一个View    final View view = mAdapter.getView(0, null, parent);    parent.addView(view);     // 强制计算当前View的宽和高    if (mChildWidth == 0 && mChildHeight == 0) {      int w = View.MeasureSpec.makeMeasureSpec(0,          View.MeasureSpec.UNSPECIFIED);      int h = View.MeasureSpec.makeMeasureSpec(0,          View.MeasureSpec.UNSPECIFIED);       view.measure(w, h);      mChildHeight = view.getMeasuredHeight();      mChildWidth = view.getMeasuredWidth();      Log.e(TAG, "子组件的宽：" + mChildWidth + ", 子组件的高：" + mChildHeight);       // 计算每次加载多少个View      mCountOneScreen = screenWidth / mChildWidth + 2;       Log.e(TAG, "mCountOneScreen = " + mCountOneScreen          + " ,mChildWidth = " + mChildWidth);    }    //初始化第一屏幕的元素    loadFirstChild(mCountOneScreen);  }   /**   * 加载第一屏的View   */  public void loadFirstChild(int mCountOneScreen) {     parent.removeAllViews();    mViewPos.clear();     for (int i = 0; i < mCountOneScreen; i++) {      View view = mAdapter.getView(i, null, parent);      view.setOnClickListener(this);      parent.addView(view);      mViewPos.put(view, i);      mCurrentIndex = i;    }     if (mListener != null) {      notifyCurrentImageChanged();    }  }   @Override  public boolean onTouchEvent(MotionEvent event) {     switch (event.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) {          loadNextImage();        }        // 如果当前scrollX = 0， 往前设置一张，移除最后一张        if (scrollX == 0) {          loadPreImage();        }        break;    }    // 这里无论返回值是设置 true 还是 false    // HorizontalScrollView都不会滑动    return super.onTouchEvent(event);  }   /**   * 加载下一张图片   */  protected void loadNextImage() {    // 数组边界值计算    if (mCurrentIndex == mAdapter.getCount() - 1) {      return;    }    //移除第一张图片，且将水平滚动位置置0（图片有宽度，所以为置0）    scrollTo(0, 0);    mViewPos.remove(parent.getChildAt(0));    parent.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, parent);    Log.e(TAG, "mCurrentIndex ===" + mCurrentIndex);    view.setOnClickListener(this);    parent.addView(view);    mViewPos.put(view, mCurrentIndex);     //当前第一张图片小标    mFristIndex++;    //如果设置了滚动监听则触发    if (mListener != null) {      notifyCurrentImageChanged();    }   }   /**   * 加载前一张图片   */  protected void loadPreImage() {    //如果当前已经是第一张，则返回    if (mFristIndex == 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 = parent.getChildCount() - 1;      mViewPos.remove(parent.getChildAt(oldViewPos));      parent.removeViewAt(oldViewPos);       //将此View放入第一个位置      View view = mAdapter.getView(index, null, parent);      mViewPos.put(view, index);      parent.addView(view, 0);      view.setOnClickListener(this);      //水平滚动位置向左移动view的宽度个像素      scrollTo(mChildWidth, 0);      //当前位置--，当前第一个显示的下标--      mCurrentIndex--;      mFristIndex--;      //回调      if (mListener != null) {        notifyCurrentImageChanged();      }    }  }   /**   * 滑动时的回调   */  public void notifyCurrentImageChanged() {     int sum = parent.getChildCount();    for (int i = 0; i < sum; i++) {      // 清除所有的背景色，点击时会设置为蓝色      parent.getChildAt(i).setBackgroundColor(Color.WHITE);    }     mListener.onCurrentImgChanged(mFristIndex, parent.getChildAt(0));  }   @Override  public void onClick(View v) {     if (mOnItemClickListener != null) {       int sum = parent.getChildCount();      for (int i = 0; i < sum; i++) {        parent.getChildAt(i).setBackgroundColor(Color.WHITE);      }      mOnItemClickListener.onItemClick(v, mViewPos.get(v));    }  }   public void setOnItemClickListener(OnItemClickListener mOnClickListener) {    this.mOnItemClickListener = mOnClickListener;  }   public void setCurrentImageChangeListener(CurrentImageChangeListener mListener) {    this.mListener = mListener;  }}

<?xml version="1.0" encoding="utf-8"?><RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"  xmlns:app="http://schemas.android.com/apk/res-auto"  xmlns:tools="http://schemas.android.com/tools"  android:layout_width="match_parent"  android:layout_height="match_parent"  android:paddingLeft="5dp"  android:paddingTop="5dp"  android:paddingRight="5dp"  android:paddingBottom="5dp"  app:layout_behavior="@string/appbar_scrolling_view_behavior"  tools:context="com.crazy.horizontalscrollviewtest.MainActivity"  tools:showIn="@layout/activity_main">    <ImageView    android:id="@+id/imageView"    android:layout_width="match_parent"    android:layout_height="380dp"    android:scaleType="centerCrop" />   <com.crazy.horizontalscrollviewtest.MyHorizontalView    android:id="@+id/my_horizontal"    android:layout_below="@id/imageView"    android:layout_alignParentBottom="true"    android:scrollbars="none"    android:layout_width="match_parent"    android:layout_height="wrap_content">     <LinearLayout      android:id="@+id/linear_layout"      android:orientation="horizontal"      android:layout_gravity="center_vertical"      android:layout_width="wrap_content"      android:layout_height="wrap_content">    </LinearLayout>  </com.crazy.horizontalscrollviewtest.MyHorizontalView> </RelativeLayout>

<?xml version="1.0" encoding="utf-8"?><RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"  android:layout_width="match_parent"  android:layout_height="match_parent"  android:orientation="vertical" >    <ImageView     android:id="@+id/top_image"    android:layout_width="wrap_content"    android:layout_height="wrap_content"    android:layout_margin="10dp"    android:scaleType="centerCrop"/> </RelativeLayout>