能够监听是否滑动到底部和顶部的scrollView
package com.danale.cloud.ui.widget;import com.danale.cloud.utils.LogUtil;import android.content.Context;import android.util.AttributeSet;import android.util.Log;import android.view.View;import android.widget.ScrollView;public class BottomTopScrollView extends ScrollView {public BottomTopScrollView(Context context, AttributeSet attrs,int defStyleAttr) {super(context, attrs, defStyleAttr);}public BottomTopScrollView(Context context, AttributeSet attrs) {super(context, attrs);}public BottomTopScrollView(Context context) {super(context);}@Overrideprotected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {super.onMeasure(widthMeasureSpec, heightMeasureSpec);int childCount = getChildCount();//计算子view的高度childHeightCount = 0;for(int i = 0 ; i < childCount ; i++){View childAt = getChildAt(i);int measuredHeight = childAt.getMeasuredHeight();LayoutParams params = (LayoutParams) childAt.getLayoutParams();childHeightCount += measuredHeight + params.topMargin + params.bottomMargin;}}private int childHeightCount;/*** clampedX : 表示在x方向是否可以移动 ,能移动false ,不能移动 true* clampedY : 表示在y方向是否可以移动* * 通过上面的参数和scrollxx参数就可以知道其是否滑到底部和滑到顶部*/@Overrideprotected void onOverScrolled(int scrollX, int scrollY, boolean clampedX,boolean clampedY) {super.onOverScrolled(scrollX, scrollY, clampedX, clampedY);LogUtil.e("BottomTopScrollView", "childHeightCount : "+childHeightCount);if(scrollY <= 0){mScrollState = ScrollState.TOP_STATE;if(scrollY >= childHeightCount - getMeasuredHeight()){mScrollState = ScrollState.BOTH_STATE;//表示scrollview 要比childs要高,不需要scrollview 去滑动}}else if(scrollY > 0){mScrollState = ScrollState.SCROLL_STATE;if(scrollY >= childHeightCount - getMeasuredHeight()){mScrollState = ScrollState.BOTTOM_STATE;//表示scrollview 要比childs要高,不需要scrollview 去滑动}}LogUtil.e("BottomTopScrollView", "scrollstate : " + mScrollState + "/ scrollY:" + scrollY);}private ScrollState mScrollState;public ScrollState getScrollState(){LogUtil.e("BottomTopScrollView", "childHeightCount : "+childHeightCount + "/ measuredHeight : " + getMeasuredHeight());if(childHeightCount <= getMeasuredHeight()){return ScrollState.BOTH_STATE;}return mScrollState;}/** 滑动位置的状态 TOP_STATE 到达顶部, BOTTOM_STATE 到达底部 , BOTH_STATE 即到达底部也达到了顶部, SCROLL_STATE 可滑动状态*/public enum ScrollState{TOP_STATE , BOTTOM_STATE , BOTH_STATE , SCROLL_STATE;}}
PullToRefreshScrollView
package com.danale.cloud.ui.widget;import com.danale.cloud.R;import com.danale.cloud.ui.widget.BottomTopScrollView.ScrollState;import com.danale.cloud.utils.LogUtil;import android.content.Context;import android.util.AttributeSet;import android.view.MotionEvent;import android.view.View;import android.view.ViewConfiguration;import android.widget.LinearLayout;import android.widget.Scroller;/***类似于qq中的界面,能够上下的拉动*/public class PullToRefreshScrollView extends LinearLayout {private BottomTopScrollView mScrollView;private float downY;private Scroller mScroller;private int mScaledTouchSlop;private boolean isInControl = false;private final int REFRESH_MIN_SCROLL_HEIGH = 100;public PullToRefreshScrollView(Context context, AttributeSet attrs) {super(context, attrs);mScroller = new Scroller(context);mScaledTouchSlop = ViewConfiguration.get(context).getScaledTouchSlop();}@Overrideprotected void onFinishInflate() {super.onFinishInflate();View view = findViewById(R.id.danale_cloud_id_pull_to_refresh_scrollview);if(!(view instanceof BottomTopScrollView)){throw new IllegalArgumentException("must be used by scrollview to viewgroup's child view !");}mScrollView = (BottomTopScrollView) view;}@Overrideprotected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {super.onMeasure(widthMeasureSpec, heightMeasureSpec);LayoutParams layoutParams = (LayoutParams) mScrollView.getLayoutParams();layoutParams.height = getMeasuredHeight() - getPaddingTop() - getPaddingBottom();layoutParams.weight = getMeasuredWidth() - getPaddingLeft() - getPaddingRight();}@Overridepublic boolean onTouchEvent(MotionEvent event) {int action = event.getAction();LogUtil.e("PullToRefreshScrollView", "onTouchEvent " + event.getX());switch (action) {case MotionEvent.ACTION_DOWN:downY = event.getY();return true;case MotionEvent.ACTION_MOVE:float moveY = event.getY();float dY = (moveY - downY)/1.5f;scrollBy(0, (int) -dY);downY = moveY;isInControl = false;break;case MotionEvent.ACTION_UP:float downY = event.getY();float scrollY = getScrollY();handlerPullToRefresh(scrollY);mScroller.startScroll(0, (int)scrollY, 0, (int)-scrollY, (int)Math.abs(scrollY));invalidate();break;default:break;}return super.onTouchEvent(event);}private void handlerPullToRefresh(float scrollY) {if(scrollY < -REFRESH_MIN_SCROLL_HEIGH && mListener != null){mListener.onRefresh();}}@Overridepublic void computeScroll() {if(puteScrollOffset()){scrollTo(0, mScroller.getCurrY());invalidate();}}@Overridepublic boolean dispatchTouchEvent(MotionEvent ev) {int action = ev.getAction();switch (action) {case MotionEvent.ACTION_DOWN:downY = ev.getX();break;case MotionEvent.ACTION_MOVE:float moveY = ev.getY();float dY = moveY - downY;int scrollY = getScrollY();if(Math.abs(dY) > mScaledTouchSlop){if(!isInControl && dY > 0 && (ScrollState.TOP_STATE.equals(mScrollView.getScrollState()) ||ScrollState.BOTH_STATE.equals(mScrollView.getScrollState())) && scrollY == 0){ // 上滑 ,满足该条件可下拉刷新isInControl = true;ev.setAction(MotionEvent.ACTION_CANCEL);MotionEvent ev2 = MotionEvent.obtain(ev);dispatchTouchEvent(ev);ev2.setAction(MotionEvent.ACTION_DOWN);return dispatchTouchEvent(ev2);}else if(!isInControl && dY < 0 &&(ScrollState.BOTTOM_STATE.equals(mScrollView.getScrollState()) ||ScrollState.BOTH_STATE.equals(mScrollView.getScrollState())) && scrollY == 0){//下滑,满足该条件可上拉加载isInControl = true;ev.setAction(MotionEvent.ACTION_CANCEL);MotionEvent ev2 = MotionEvent.obtain(ev);dispatchTouchEvent(ev);ev2.setAction(MotionEvent.ACTION_DOWN);return dispatchTouchEvent(ev2);}}break;default:break;}return super.dispatchTouchEvent(ev);}@Overridepublic boolean onInterceptTouchEvent(MotionEvent ev) {LogUtil.e("PullToRefreshScrollView","onInterceptTouchEvent");int action = ev.getAction();switch (action) {case MotionEvent.ACTION_DOWN:downY = ev.getY();break;case MotionEvent.ACTION_MOVE:float moveY = ev.getY();float dY = moveY - downY;if(Math.abs(dY) > mScaledTouchSlop){if(dY > 0 && (ScrollState.TOP_STATE.equals(mScrollView.getScrollState()) ||ScrollState.BOTH_STATE.equals(mScrollView.getScrollState()))){ // 上滑 ,满足该条件可下拉刷新return true;}else if(dY < 0 &&(ScrollState.BOTTOM_STATE.equals(mScrollView.getScrollState()) ||ScrollState.BOTH_STATE.equals(mScrollView.getScrollState()))){//下滑,满足该条件可上拉加载return true;}}break;default:break;}return super.onInterceptTouchEvent(ev);}public interface OnPullToRefreshListener{public void onRefresh();}private OnPullToRefreshListener mListener;public void setOnPullToRefreshListener(OnPullToRefreshListener listener){this.mListener = listener;}}
布局相关的问题
<?xml version="1.0" encoding="utf-8"?><LinearLayout xmlns:android="/apk/res/android"android:layout_width="match_parent"android:layout_height="match_parent"android:orientation="vertical" ><com.example.drawable_ui.view.PullToRefreshScrollViewandroid:id="@+id/pull_to_refresh_scroll"android:layout_width="match_parent"android:layout_height="match_parent" ><com.example.drawable_ui.view.BottomTopScrollViewandroid:id="@id/id_pull_to_refresh_scrollview"android:layout_width="match_parent"android:layout_height="match_parent" ><LinearLayoutandroid:layout_width="match_parent"android:layout_height="wrap_content"android:orientation="vertical" ><TextViewandroid:layout_width="match_parent"android:layout_height="200dp"android:background="#ffa22c"android:gravity="center_vertical"android:text="sdfadaddddad" android:clickable="true"android:onClick="clickTv3" />若干个textview....</LinearLayout></com.example.drawable_ui.view.BottomTopScrollView></com.example.drawable_ui.view.PullToRefreshScrollView></LinearLayout>
values 文件加下 ids.xml
<?xml version="1.0" encoding="utf-8"?><resources> <item name="id_pull_to_refresh_scrollview" type="id"></item></resources>
在代码中设置setOnPullToRefreshListener(OnPullToRefreshListener listener),就可以实现下拉刷新了
