TextView不能在ListeView中单独的滚动原因
默认ListView将会拦截MOVE事件向下传递
参见源码
case MotionEvent.ACTION_MOVE: {switch (mTouchMode) {case TOUCH_MODE_DOWN:int pointerIndex = ev.findPointerIndex(mActivePointerId);if (pointerIndex == -1) {pointerIndex = 0;mActivePointerId = ev.getPointerId(pointerIndex);}final int y = (int) ev.getY(pointerIndex);initVelocityTrackerIfNotExists();mVelocityTracker.addMovement(ev);if (startScrollIfNeeded((int) ev.getX(pointerIndex), y, null)) {//此处将会拦截事件的传递return true;}break;}break;}
方案
使用NestedScrollChild\NestedScrollParent进行实现
Android 5.0 Lollipop 提供该套功能的API,NestedScrollChild\NestedScrollParent的定义集成到了View,ViewGroup中，V4包中提供向前兼容的API
具体步骤-此处采用集成的API，而未采用直接继承NestedScrollChild/NestedScrollParent
xml文件设置
TextView设置属性：android:nestedScrollingEnable=”true” //允许进行嵌套滚动
代码设置
ListeView中的改写
改写事件拦截条件，默认拦截ACTION_MOVE,不传递给子View
改写实现
/**
* 改写MotionEvent 拦截条件,当子View中有需要请求nested scroll 的时候不进行拦截
*/
override fun onInterceptTouchEvent(ev: MotionEvent): Boolean {
var superIntecept: Boolean
val actionMasked = ev.actionMasked
//先不改变ListView的默认实现，在下面的代码中根据情况进行拦截修改
superIntecept = super.onInterceptTouchEvent(ev)
//当进行移动，且有子View需nested scroll,则一定不拦截when (actionMasked) {MotionEvent.ACTION_MOVE -> {//选择性的拦截-有需要配合nested scroll的子View则不拦截，否则拦截//nestedScrollAxes默认为SCROLL_AXIS_NONE=0，即没有子View调用startNestedScroll向其进行nestedScroll的请求if (nestedScrollAxes and ViewCompat.SCROLL_AXIS_VERTICAL == ViewCompat.SCROLL_AXIS_VERTICAL) {val parent = parentparent?.requestDisallowInterceptTouchEvent(true)return false}}}return superIntecept
}
TextView中的改写
改写onTouchEvent，当刚触摸时立即请求NestedScroll ，即调用startNestedScroll（View中已实现）
具体实现
override fun onTouchEvent(event: MotionEvent?): Boolean {var action = event!!.actionMaskedwhen (action) {//down之后就开始nested scroll声明，并请求父View不拦截 touch eventMotionEvent.ACTION_DOWN -> {startNestedScroll(ViewCompat.SCROLL_AXIS_VERTICAL)val parent = parentparent?.requestDisallowInterceptTouchEvent(true)}}return super.onTouchEvent(event)
}
附-NestedScrollChild/NestedScrollParent使用介绍相关博客
https://blog.csdn.net/chen930724/article/details/50307193
https://blog.csdn.net/lmj623565791/article/details/52204039
http://www.jcodecraeer.com/a/anzhuokaifa/androidkaifa/2015/0822/3342.html
https://segmentfault.com/a/1190000002873657
