在android中ScrollView嵌套ScrollView解决方案
大家好,众所周知,android里两个相同方向的ScrollView是不能嵌套的,那要是有这样的需求怎么办?(这个需求一般都是不懂android的人提出来的)
难道就真的不能嵌套吗?当然可以,只要你再写一个ScrollView,在里面做点脚,它就支持嵌套了。
目前做的这个只支持两个ScrollView嵌套,两个以上还有待改进,能套两个就已经能满足很多需求了,呵呵,另外现在只做了纵向scrollview的支持,横向的还没来的急做哦。
效果截图:
先上核心代码吧。代码里头我加了注释,方便大家阅读
代码如下:
package com.sun.shine.study.innerscrollview.view;
import android.content.Context;
import android.util.AttributeSet;
import android.view.MotionEvent;
import android.view.View;
import android.widget.ScrollView;
public class InnerScrollView extends ScrollView {
/**
*/
public ScrollView parentScrollView;
public InnerScrollView(Context context, AttributeSet attrs) {
super(context, attrs);
}
private int lastScrollDelta = 0;
public void resume() {
overScrollBy(0, -lastScrollDelta, 0, getScrollY(), 0, getScrollRange(), 0, 0, true);
lastScrollDelta = 0;
}
int mTop = 10;
/**
* 将targetView滚到最顶端
*/
public void scrollTo(View targetView) {
int oldScrollY = getScrollY();
int top = targetView.getTop() - mTop;
int delatY = top - oldScrollY;
lastScrollDelta = delatY;
overScrollBy(0, delatY, 0, getScrollY(), 0, getScrollRange(), 0, 0, true);
}
private int getScrollRange() {
int scrollRange = 0;
if (getChildCount() > 0) {
View child = getChildAt(0);
scrollRange = Math.max(0, child.getHeight() - (getHeight()));
}
return scrollRange;
}
int currentY;
@Override
public boolean onInterceptTouchEvent(MotionEvent ev) {
if (parentScrollView == null) {
return super.onInterceptTouchEvent(ev);
} else {
if (ev.getAction() == MotionEvent.ACTION_DOWN) {
// 将父scrollview的滚动事件拦截
currentY = (int)ev.getY();
setParentScrollAble(false);
return super.onInterceptTouchEvent(ev);
} else if (ev.getAction() == MotionEvent.ACTION_UP) {
// 把滚动事件恢复给父Scrollview
setParentScrollAble(true);
} else if (ev.getAction() == MotionEvent.ACTION_MOVE) {
}
}
return super.onInterceptTouchEvent(ev);
}
@Override
public boolean onTouchEvent(MotionEvent ev) {
View child = getChildAt(0);
if (parentScrollView != null) {
if (ev.getAction() == MotionEvent.ACTION_MOVE) {
int height = child.getMeasuredHeight();
height = height - getMeasuredHeight();
// System.out.println("height=" + height);
int scrollY = getScrollY();
// System.out.println("scrollY" + scrollY);
int y = (int)ev.getY();
// 手指向下滑动
if (currentY < y) {
if (scrollY <= 0) {
// 如果向下滑动到头,就把滚动交给父Scrollview
setParentScrollAble(true);
return false;
} else {
setParentScrollAble(false);
}
} else if (currentY > y) {
if (scrollY >= height) {
// 如果向上滑动到头,就把滚动交给父Scrollview
setParentScrollAble(true);
return false;
} else {
setParentScrollAble(false);
}
}
currentY = y;
}
}
return super.onTouchEvent(ev);
}
/**
* 是否把滚动事件交给父scrollview
*
* @param flag
*/
private void setParentScrollAble(boolean flag) {
parentScrollView.requestDisallowInterceptTouchEvent(!flag);
}
}