ScrollView滑动到底部或顶部后，再继续滑动达到一定距离的监听；
ScrollView滑动到底部或顶部的监听；
/**
* 监听ScrollView滚动到顶部或者底部做相关事件拦截
*/
public class ContinueSlideScrollView extends ScrollView {
private boolean isScrolledToTop = true;// 初始化的时候设置一下值
private boolean isScrolledToBottom = false;
private Context context;
private ISmartScrollChangedListener mSmartScrollChangedListener;
public ContinueSlideScrollView(Context context) {
super(context);
this.context = context;
}
public ContinueSlideScrollView(Context context, AttributeSet attrs) {
super(context, attrs);
this.context = context;
}
public ContinueSlideScrollView(Context context, AttributeSet attrs, int defStyleAttr) {
super(context, attrs, defStyleAttr);
this.context = context;
}
/**
* 滑动到顶部或底部的监听接口
* */
public interface ISmartScrollChangedListener {
void onScrolledToBottom();
void onScrolledToTop();
}
public void setScanScrollChangedListener(ISmartScrollChangedListener smartScrollChangedListener) {
mSmartScrollChangedListener = smartScrollChangedListener;
}
@Override
protected void onOverScrolled(int scrollX, int scrollY, boolean clampedX, boolean clampedY) {
super.onOverScrolled(scrollX, scrollY, clampedX, clampedY);
if (scrollY == 0) {
isScrolledToTop = clampedY;
isScrolledToBottom = false;
} else {
isScrolledToTop = false;
isScrolledToBottom = clampedY;
}
notifyScrollChangedListeners();
}
@Override
protected void onScrollChanged(int l, int t, int oldl, int oldt) {
super.onScrollChanged(l, t, oldl, oldt);
if (android.os.Build.VERSION.SDK_INT < 9) { // API 9及之后走onOverScrolled方法监听
if (getScrollY() == 0) {
isScrolledToTop = true;
isScrolledToBottom = false;
} else if (getScrollY() + getHeight() - getPaddingTop()-getPaddingBottom() == getChildAt(0).getHeight()) {
isScrolledToBottom = true;
isScrolledToTop = false;
} else {
isScrolledToTop = false;
isScrolledToBottom = false;
}
notifyScrollChangedListeners();
}
}
private void notifyScrollChangedListeners() {
if (isScrolledToTop) {
if (mSmartScrollChangedListener != null) {
mSmartScrollChangedListener.onScrolledToTop();
}
} else if (isScrolledToBottom) {
if (mSmartScrollChangedListener != null) {
mSmartScrollChangedListener.onScrolledToBottom();
}
}
}
public boolean isScrolledToTop() {
return isScrolledToTop;
}
public boolean isScrolledToBottom() {
return isScrolledToBottom;
}
/**
* 继续滑动的代码
*/
private float down,move;
private boolean isExecute = false; //是否要执行
private int TRIGGER_DISTANCE = 160; //继续滑动效果触发间距 dp
@Override
public boolean onTouchEvent(MotionEvent ev) {
switch (ev.getAction()){
case MotionEvent.ACTION_DOWN:
down = ev.getY();
isExecute = true;
break;
case MotionEvent.ACTION_MOVE:
move = ev.getY();
if (isExecute && isScrolledToTop() && move - down > dp2px(context,TRIGGER_DISTANCE)){
isExecute = false;
Log.i("ccb", "onTouchEvent: 回到顶部，继续滑动"+(move - down));
if (continueSlide != null)continueSlide.onContinueSlideTop();
}
if (isExecute && isScrolledToBottom() && move - down < (-dp2px(context,TRIGGER_DISTANCE))){
isExecute = false;
Log.i("ccb", "onTouchEvent: 已经到底，继续滑动"+((move - down)));
if (continueSlide != null)continueSlide.onContinueSlideBottom();
}
break;
case MotionEvent.ACTION_UP:
isExecute = true;
move = 0;
down = 0 ;
break;
}
return super.onTouchEvent(ev);
}
/**
* 滑动到顶部或底部继续滑动到一定距离触发
*/
public interface onContinueSlide{
void onContinueSlideTop();
void onContinueSlideBottom();
}
public onContinueSlide continueSlide;
public void setonContinueSlideListener(onContinueSlide continueSlide){
this.continueSlide = continueSlide;
}
/**
* dip转换px
*/
public static int dp2px(Context content, int dip) {
final float scale = content.getResources().getDisplayMetrics().density;
return (int) (dip * scale + 0.5f);
}
}
实现了一下，仿淘宝从商品页继续上拉进入商品详情页的效果：https://github.com/CuiChenbo/DoubleFragmentSwitch