Android开发ScrollView上下左右滑动事件冲突整理一(根据事件)
主要通过重写 onInterceptTouchEvent 事件来解决,代码如下:
- package com.cm.android.pad.view.itemView;
- import android.content.Context;
- import android.util.AttributeSet;
- import android.util.DisplayMetrics;
- import android.util.Log;
- import android.view.MotionEvent;
- import android.view.VelocityTracker;
- import android.view.ViewConfiguration;
- import android.view.WindowManager;
- import android.widget.ScrollView;
- import android.widget.Scroller;
- public class MultiScroll extends ScrollView {
- private static final int ANIMATION_SCREEN_SET_DURATION_MILLIS = 500;
- // What fraction (1/x) of the screen the user must swipe to indicate a page change
- private static final int FRACTION_OF_SCREEN_WIDTH_FOR_SWIPE = 4;
- private static final int INVALID_SCREEN = -1;
- /*
- * Velocity of a swipe (in density-independent pixels per second) to force a swipe to the
- * next/previous screen. Adjusted into mDensityAdjustedSnapVelocity on init.
- */
- private static final int SNAP_VELOCITY_DIP_PER_SECOND = 600;
- // Argument to getVelocity for units to give pixels per second (1 = pixels per millisecond).
- private static final int VELOCITY_UNIT_PIXELS_PER_SECOND = 1000;
- private static final int TOUCH_STATE_REST = 0;
- private static final int TOUCH_STATE_HORIZONTAL_SCROLLING = 1;
- private static final int TOUCH_STATE_VERTICAL_SCROLLING = -1;
- private int mCurrentScreen;
- private int mDensityAdjustedSnapVelocity;
- private boolean mFirstLayout = true;
- private float mLastMotionX;
- private float mLastMotionY;
- //private OnScreenSwitchListener mOnScreenSwitchListener;
- private int mMaximumVelocity;
- private int mNextScreen = INVALID_SCREEN;
- private Scroller mScroller;
- private int mTouchSlop;
- private int mTouchState = TOUCH_STATE_REST;
- private VelocityTracker mVelocityTracker;
- private int mLastSeenLayoutWidth = -1;
- public MultiScroll(Context context) {
- super(context);
- init();
- }
- public MultiScroll(Context context, AttributeSet attrs, int defStyle) {
- super(context, attrs, defStyle);
- init();
- }
- public MultiScroll(Context context, AttributeSet attrs) {
- super(context, attrs);
- init();
- }
- private void init() {
- mScroller = new Scroller(getContext());
- // Calculate the density-dependent snap velocity in pixels
- DisplayMetrics displayMetrics = new DisplayMetrics();
- ((WindowManager) getContext().getSystemService(Context.WINDOW_SERVICE)).getDefaultDisplay()
- .getMetrics(displayMetrics);
- mDensityAdjustedSnapVelocity =
- (int) (displayMetrics.density * SNAP_VELOCITY_DIP_PER_SECOND);
- final ViewConfiguration configuration = ViewConfiguration.get(getContext());
- mTouchSlop = configuration.getScaledTouchSlop();
- mMaximumVelocity = configuration.getScaledMaximumFlingVelocity();
- }
- @Override
- public boolean onInterceptTouchEvent(final MotionEvent ev) {
- /*
- * By Yoni Samlan: Modified onInterceptTouchEvent based on standard ScrollView's
- * onIntercept. The logic is designed to support a nested vertically scrolling view inside
- * this one; once a scroll registers for X-wise scrolling, handle it in this view and don't
- * let the children, but once a scroll registers for y-wise scrolling, let the children
- * handle it exclusively.
- */
- final int action = ev.getAction();
- boolean intercept = false;
- switch (action) {
- case MotionEvent.ACTION_MOVE:
- /*
- * If we're in a horizontal scroll event, take it (intercept further events). But if
- * we're mid-vertical-scroll, don't even try; let the children deal with it. If we
- * haven't found a scroll event yet, check for one.
- */
- if (mTouchState == TOUCH_STATE_HORIZONTAL_SCROLLING) {
- // Let children handle the events for the duration of the scroll event.
- intercept = false;
- } else if (mTouchState == TOUCH_STATE_VERTICAL_SCROLLING) {
- /*
- * We've already started a horizontal scroll; set intercept to true so we can
- * take the remainder of all touch events in onTouchEvent.
- */
- intercept = true;
- } else { // We haven't picked up a scroll event yet; check for one.
- /*
- * If we detected a horizontal scroll event, start stealing touch events (mark
- * as scrolling). Otherwise, see if we had a vertical scroll event -- if so, let
- * the children handle it and don't look to intercept again until the motion is
- * done.
- */
- final float x = ev.getX();
- final int xDiff = (int) Math.abs(x - mLastMotionX);
- boolean xMoved = xDiff > mTouchSlop;
- final float y = ev.getY();
- final int yDiff = (int) Math.abs(y - mLastMotionY);
- boolean yMoved = yDiff > mTouchSlop;
- if (xMoved) {
- // Scroll if the user moved far enough along the X axis
- if(xDiff>=yDiff)
- mTouchState = TOUCH_STATE_HORIZONTAL_SCROLLING;
- mLastMotionX = x;
- }
- if (yMoved) {
- if(yDiff>xDiff)
- mTouchState = TOUCH_STATE_VERTICAL_SCROLLING;
- mLastMotionY = y;
- }
- }
- break;
- case MotionEvent.ACTION_CANCEL:
- case MotionEvent.ACTION_UP:
- // Release the drag.
- mTouchState = TOUCH_STATE_REST;
- intercept = false;
- break;
- case MotionEvent.ACTION_DOWN:
- /*
- * No motion yet, but register the coordinates so we can check for intercept at the
- * next MOVE event.
- */
- //Log.i("ViewPager-->", "Action_Down");
- mTouchState = TOUCH_STATE_REST;
- mLastMotionY = ev.getY();
- mLastMotionX = ev.getX();
- break;
- default:
- break;
- }
- Log.i("MultiScroll-->", intercept+"");
- return intercept;
- }
- }