android 自定义viewpager _自定义View

别裁伪体亲风雅，转益多师是汝师。这篇文章主要讲述android 自定义viewpager相关的知识，希望能为你提供帮助。

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× 当前代码只实现了自定义 viewpager 指定大小显示，滑动事件，单击事件
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package com.example.myviewpager.views; import android.content.Context; import android.graphics.Color; import android.os.SystemClock; import android.util.AttributeSet; import android.view.MotionEvent; import android.view.View; import android.view.ViewGroup; import android.widget.Scroller; public class MyViewPager extends ViewGroup {private static final String TAG = "Tag"; private int mWidth; //总宽度 private int mHeight; //总高 private float startX; //记录点击时位置 private int pagerWidth; //每个孩子宽度 private int currentItem; //显示当前孩子index private Scroller scroller; private long downTime; private OnViewPagerItemClickListener onViewPagerItemClickListener; private OnScrollListener onScrollListener; public OnScrollListener getOnScrollListener() { return onScrollListener; }public void setOnScrollListener(OnScrollListener onScrollListener) { this.onScrollListener = onScrollListener; }public MyViewPager.OnViewPagerItemClickListener getOnViewPagerClickListener() { return onViewPagerItemClickListener; }public void setOnViewPagerClickListener(MyViewPager.OnViewPagerItemClickListener onViewPagerItemClickListener) { this.onViewPagerItemClickListener = onViewPagerItemClickListener; }public MyViewPager(Context context) { super(context); }public MyViewPager(final Context context, AttributeSet attrs) { super(context, attrs); scroller = new Scroller(context); ViewGroup.LayoutParams lp = new LayoutParams(LayoutParams.MATCH_PARENT, LayoutParams.MATCH_PARENT); for (int i = 0; i < 3; i++) { View view = new View(context); if (i == 0) view.setBackgroundColor(Color.RED); if (i == 1) view.setBackgroundColor(Color.YELLOW); if (i == 2) view.setBackgroundColor(Color.BLUE); view.setLayoutParams(lp); view.setTag(i); addView(view); } }public MyViewPager(Context context, AttributeSet attrs, int defStyleAttr) { super(context, attrs, defStyleAttr); }@Override protected void onLayout(boolean changed, int l, int t, int r, int b) { if (changed) { int childCount = getChildCount(); for (int i = 0; i < childCount; i++) {//布局每个孩子 View child = getChildAt(i); child.layout(i * pagerWidth, 0, (i + 1) * pagerWidth, mHeight); } } }@Override protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) { super.onMeasure(widthMeasureSpec, heightMeasureSpec); int childCount = getChildCount(); if (childCount > 0) { View childAt = getChildAt(0); childAt.measure(widthMeasureSpec, heightMeasureSpec); int measuredHeight = childAt.getMeasuredHeight(); int measuredWidth = childAt.getMeasuredWidth(); mWidth = measuredWidth * childCount; mHeight = measuredHeight; pagerWidth = measuredWidth; setMeasuredDimension(pagerWidth, mHeight); //设置pager 尺寸，宽度为一个孩子宽度， // 如果为所有孩子宽度之和会显示所有孩子（当pager没有沾满屏幕） } }@Override public boolean onInterceptTouchEvent(MotionEvent ev) { return true; }boolean isclick = false; @Override public void computeScroll() { super.computeScroll(); if (scroller.computeScrollOffset()) { scrollTo(scroller.getCurrX(), 0); if (onScrollListener != null) { onScrollListener.onScroll(currentItem, getScrollX()); } postInvalidate(); } }boolean once = false; @Override public boolean onTouchEvent(MotionEvent event) { super.onTouchEvent(event); switch (event.getAction()) { case MotionEvent.ACTION_DOWN: downTime = SystemClock.currentThreadTimeMillis(); startX = event.getX(); break; case MotionEvent.ACTION_MOVE: if (!once) {//只要滑动距离有一次大于指定的距离就认为是滑动状态，后续滑动不受距离限制 float distance = event.getX() - startX; if (Math.abs(distance) > 8) { once = true; isclick = false; //不是单击，而是滑动 } else isclick = true; } else { float distance = event.getX() - startX; scrollBy(-(int) distance, 0); if (getScrollX() < = 0) {//当是第一页时禁止右滑 scrollTo(0, 0); currentItem = 1; } if (getScrollX() - pagerWidth * (getChildCount() - 1) > 0) {//当是最后一页禁止左滑 scrollTo(pagerWidth * (getChildCount() - 1), 0); currentItem = getChildCount(); } if (onScrollListener != null) {//调用滑动监听 onScrollListener.onScroll(currentItem, getScrollX()); } startX = event.getX(); isclick = false; } break; case MotionEvent.ACTION_UP: long upTime = SystemClock.currentThreadTimeMillis(); long useTime = upTime - downTime; if (once & & !isclick) { startX = 0; int scrolleX = getScrollX(); int index = (scrolleX + pagerWidth / 2) / pagerWidth; //滑动超半下一个，否则还原上一个 scroller.startScroll(scrolleX, 0, index * pagerWidth - scrolleX, 0); currentItem = index; postInvalidate(); once = false; } if (!once & & isclick & & useTime < 50) {//调用点击监听，小于50毫秒认为是点击，大于是长按没实现长按 if (onViewPagerItemClickListener != null) onViewPagerItemClickListener.onClick(currentItem); isclick = true; } break; }return true; }public interface OnViewPagerItemClickListener { void onClick(int position); }public interface OnScrollListener { void onScroll(int pageNum, int scrolx); } }

【android 自定义viewpager】