自定义左右滑动图片列表

Posted 2020-09-19 翻滚的咸鱼

xml引用

代码初始化

控件代码

package com.feilu.investadviser.ui.main.widget;

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.WindowManager;
import android.widget.HorizontalScrollView;
import android.widget.LinearLayout;

import com.feilu.investadviser.ui.main.adapter.HorizontalScrollViewAdapter;

import java.util.HashMap;
import java.util.Map;


public class HzScrollView extends HorizontalScrollView implements View.OnClickListener {

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

    /**
     * 条目点击时的回调
     *
     */
    public interface OnItemClickListener {
        void onClick(View view, int pos);
    }

    private CurrentImageChangeListener mListener;

    private OnItemClickListener mOnClickListener;

    private static final String TAG = "HzScrollView";

    /**
     * HorizontalListView中的LinearLayout
     */
    private LinearLayout mContainer;
    /**
     * 子元素的宽度
     */
    private int mChildWidth;
    /**
     * 子元素的高度
     */
    private int mChildHeight;
    /**
     * 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;
    /**
     * 当前第一个View
     */
    private View mFirstView;
    /**
     * 数据适配器
     */
    private HorizontalScrollViewAdapter mAdapter;
    /**
     * 每屏幕最多显示的个数
     */
    private int mCountOneScreen;
    /**
     * 屏幕的宽度
     */
    private int mScreenWitdh;

    /**
     * 保存View与位置的键值对
     */
    private Map<View, Integer> mViewPos = new HashMap<View, Integer>();

    public HzScrollView(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);
        mScreenWitdh = 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，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
        mFristIndex++;
        // 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 (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) {
            // mContainer = (LinearLayout) getChildAt(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) {
                notifyCurrentImgChanged();

            }
        }
    }

    /**
     * 滑动时的回调
     */
    public 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(mFristIndex, mContainer.getChildAt(0));

    }

    /**
     * 初始化数据，设置数据适配器
     *
     */
    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, view.getMeasuredWidth() + "," + view.getMeasuredHeight());
            mChildHeight = view.getMeasuredHeight();
            // 计算每次加载多少个View
            mCountOneScreen = mScreenWitdh / mChildWidth + 2;

            Log.e(TAG, "mCountOneScreen = " + mCountOneScreen
                    + " ,mChildWidth = " + mChildWidth);

        }
        // 初始化第一屏幕的元素
        initFirstScreenChildren(mAdapter.getCount());
    }

    /**
     * 加载第一屏的View
     *
     * @param mCountOneScreen
     */
    public 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:
                // Log.e(TAG, getScrollX() + "");

                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 setCurrentImageChangeListener(
            CurrentImageChangeListener mListener) {
        this.mListener = mListener;
    }

}

View Code

adapter

package com.feilu.investadviser.ui.main.adapter;

import android.content.Context;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.ImageView;
import android.widget.TextView;

import com.feilu.investadviser.R;
import com.feilu.investadviser.ui.main.bean.RanksRenQiEntity;

import java.util.List;

public class HorizontalScrollViewAdapter {

    private Context context;
    private LayoutInflater mInflater;
    private List<RanksRenQiEntity.DataBean> mDatas;

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

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

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

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

    public void setList(List<RanksRenQiEntity.DataBean> mDatas){
        this.mDatas.clear();
        this.mDatas.addAll(mDatas);
    }

    public View getView(int position, View convertView, ViewGroup parent) {
        ViewHolder holder = null;
        if (convertView == null) {
            holder = new ViewHolder();
            convertView = mInflater.inflate(R.layout.item_ranks_scroll,
                    parent, false);
//            holder.mImg = (ImageView) convertView.findViewById(R.id.img);
//            holder.del = (ImageView) convertView.findViewById(R.id.del);

            convertView.setTag(holder);
        } else {
            holder = (ViewHolder) convertView.getTag();
        }

        return convertView;
    }

    static class ViewHolder {

    }

}

View Code