在Android应用中,一般TabActivity和若干个Tab选项卡(TabWidget)。如果选项卡的数量超过了5个,就不适合放到一个屏幕中,这样可以让这些选项卡滑动起来。
滑动的选项卡的实现有好几种方式,在这些方式中,最简单也是我最满意的还是在原生的TabActivity上修改,将上面的选项卡改为可滑动的状态。这样既有新的滑动的效果,也保留了原有TabActivity的各项功能。
实现Tab可滑动基本的思路就是把上面的TabWidget放到一个HorizontalScrollView中,让TabWidget滑动起来。不过如果仅仅修改XML还是会产生问题,就是没有办法控制每个选项卡的宽度。所以还是需要在程序中设置每个选项卡的宽度。例如:
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自定义TabActivity主界面的XML:
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效果图如下
上面的tab是可以滑动的,屏幕左右滑动,tab也会切换
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这是模仿qq的滑动实现,和tab不是一个思路,也比较美观实用可以借鉴
滑动的选项卡的实现有好几种方式,在这些方式中,最简单也是我最满意的还是在原生的TabActivity上修改,将上面的选项卡改为可滑动的状态。这样既有新的滑动的效果,也保留了原有TabActivity的各项功能。
实现Tab可滑动基本的思路就是把上面的TabWidget放到一个HorizontalScrollView中,让TabWidget滑动起来。不过如果仅仅修改XML还是会产生问题,就是没有办法控制每个选项卡的宽度。所以还是需要在程序中设置每个选项卡的宽度。例如:
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// 设置窗口的宽度
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DisplayMetrics dm = new DisplayMetrics();
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getWindowManager().getDefaultDisplay().getMetrics(dm);
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int screenWidth = dm.widthPixels;
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if (count < 4) {
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for (int i = 0; i < count; i++) {
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// 设置每个选项卡的宽度
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tabWidget.getChildTabViewAt(i).setMinimumWidth(screenWidth / 4);
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}
- }
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<linearlayout xmlns:android="http://schemas.android.com/apk/res/android"
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android:orientation="vertical" android:layout_width="fill_parent"
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android:layout_height="fill_parent">
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<tabhost android:id="@android:id/tabhost" android:layout_width="fill_parent"
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android:layout_height="fill_parent">
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<linearlayout android:orientation="vertical"
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android:layout_width="fill_parent" android:layout_height="fill_parent">
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<horizontalscrollview android:layout_height="wrap_content"
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android:layout_width="fill_parent" android:scrollbars="none">
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<tabwidget android:id="@android:id/tabs"
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android:layout_width="fill_parent" android:layout_height="60dp" />
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<framelayout android:id="@android:id/tabcontent"
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android:layout_width="fill_parent" android:layout_height="wrap_content"
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android:layout_weight="1" />
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上面的tab是可以滑动的,屏幕左右滑动,tab也会切换
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package com.xu81.testflip;
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import java.util.Vector;
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import android.content.Context;
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import android.util.AttributeSet;
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import android.view.MotionEvent;
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import android.view.VelocityTracker;
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import android.view.View;
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import android.view.ViewConfiguration;
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import android.view.ViewGroup;
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import android.widget.Scroller;
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public class ScrollLayout extends ViewGroup {
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private Scroller mScroller;
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private VelocityTracker mVelocityTracker;
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private int mCurScreen;
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private int mDefaultScreen = 0;
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private static final int TOUCH_STATE_REST = 0;
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private static final int TOUCH_STATE_SCROLLING = 1;
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private static final int SNAP_VELOCITY = 500;
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private int mTouchState = TOUCH_STATE_REST;
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private int mTouchSlop;
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private float mLastMotionX;
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private int sensitivity = 30;
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private boolean spring;
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private Vector listeners;
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public ScrollLayout(Context context, AttributeSet attrs) {
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super(context, attrs);
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// TODO Auto-generated constructor stub
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mScroller = new Scroller(context);
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mCurScreen = mDefaultScreen;
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mTouchSlop = ViewConfiguration.get(getContext()).getScaledTouchSlop();
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listeners = new Vector();
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}
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public void addChangeListener(LayoutChangeListener listener) {
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listeners.add(listener);
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}
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@Override
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protected void onLayout(boolean changed, int l, int t, int r, int b) {
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// TODO Auto-generated method stub
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int childLeft = 0;
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final int childCount = getChildCount();
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for (int i = 0; i < childCount; i++) {
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final View childView = getChildAt(i);
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if (childView.getVisibility() != View.GONE) {
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final int childWidth = childView.getMeasuredWidth();
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childView.layout(childLeft, 0, childLeft + childWidth,
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childView.getMeasuredHeight());
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childLeft += childWidth;
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}
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}
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}
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@Override
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protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {
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super.onMeasure(widthMeasureSpec, heightMeasureSpec);
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final int width = MeasureSpec.getSize(widthMeasureSpec);
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final int widthMode = MeasureSpec.getMode(widthMeasureSpec);
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if (widthMode != MeasureSpec.EXACTLY) {
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throw new IllegalStateException(
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"ScrollLayout only canmCurScreen run at EXACTLY mode!");
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}
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final int heightMode = MeasureSpec.getMode(heightMeasureSpec);
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if (heightMode != MeasureSpec.EXACTLY) {
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throw new IllegalStateException(
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"ScrollLayout only can run at EXACTLY mode!");
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}
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// The children are given the same width and height as the scrollLayout
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final int count = getChildCount();
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for (int i = 0; i < count; i++) {
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getChildAt(i).measure(widthMeasureSpec, heightMeasureSpec);
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}
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scrollTo(mCurScreen * width, 0);
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}
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public void snapToDestination() {
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final int screenWidth = getWidth();
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final int destScreen = (getScrollX() + screenWidth / 2) / screenWidth;
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snapToScreen(destScreen);
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}
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public void snapToScreen(int whichScreen) {
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// get the valid layout page
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int lastIndex = mCurScreen;
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whichScreen = Math.max(0, Math.min(whichScreen, getChildCount() - 1));
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if (getScrollX() != (whichScreen * getWidth())) {
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final int delta = whichScreen * getWidth() - getScrollX();
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mScroller.startScroll(getScrollX(), 0, delta, 0,
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Math.abs(delta) * 2);
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mCurScreen = whichScreen;
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invalidate(); // Redraw the layout
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}
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for (LayoutChangeListener listener : listeners)
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listener.doChange(lastIndex, whichScreen);
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}
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public void setToScreen(int whichScreen) {
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whichScreen = Math.max(0, Math.min(whichScreen, getChildCount() - 1));
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mCurScreen = whichScreen;
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scrollTo(whichScreen * getWidth(), 0);
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}
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public int getCurScreen() {
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return mCurScreen;
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}
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@Override
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public void computeScroll() {
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// TODO Auto-generated method stub
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if (mScroller.computeScrollOffset()) {
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scrollTo(mScroller.getCurrX(), mScroller.getCurrY());
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postInvalidate();
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}
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}
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public boolean isSpring() {
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return spring;
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}
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public void setSpring(boolean spring) {
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this.spring = spring;
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}
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@Override
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public boolean onTouchEvent(MotionEvent event) {
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// TODO Auto-generated method stub
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if (mVelocityTracker == null)
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mVelocityTracker = VelocityTracker.obtain();
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mVelocityTracker.addMovement(event);
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final int action = event.getAction();
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final float x = event.getX();
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switch (action) {
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case MotionEvent.ACTION_DOWN:
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if (!mScroller.isFinished())
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mScroller.abortAnimation();
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mLastMotionX = x;
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break;
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case MotionEvent.ACTION_MOVE:
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int deltaX = (int) (mLastMotionX - x);
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if (Math.abs(deltaX) > sensitivity) {
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// 左滑动为正数、右为负数
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if (spring) {
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scrollBy(deltaX, 0);
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mLastMotionX = x;
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} else {
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final int childCount = getChildCount();
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boolean max = mCurScreen < childCount - 1;
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boolean min = mCurScreen > 0;
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boolean canMove = deltaX > 0 ? (max ? true : false)
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: (min ? true : false);
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if (canMove) {
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scrollBy(deltaX, 0);
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mLastMotionX = x;
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}
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}
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}
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break;
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case MotionEvent.ACTION_UP:
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final VelocityTracker velocityTracker = mVelocityTracker;
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velocityTracker.computeCurrentVelocity(1000);
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int velocityX = (int) velocityTracker.getXVelocity();
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if (velocityX > SNAP_VELOCITY && mCurScreen > 0) {
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// Fling enough to move left
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snapToScreen(mCurScreen - 1);
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} else if (velocityX < -SNAP_VELOCITY
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&& mCurScreen < getChildCount() - 1) {
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// Fling enough to move right
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snapToScreen(mCurScreen + 1);
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} else {
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snapToDestination();
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}
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if (mVelocityTracker != null) {
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mVelocityTracker.recycle();
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mVelocityTracker = null;
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}
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mTouchState = TOUCH_STATE_REST;
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break;
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case MotionEvent.ACTION_CANCEL:
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mTouchState = TOUCH_STATE_REST;
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break;
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}
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return true;
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}
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@Override
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public boolean onInterceptTouchEvent(MotionEvent ev) {
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// TODO Auto-generated method stub
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final int action = ev.getAction();
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if ((action == MotionEvent.ACTION_MOVE)
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&& (mTouchState != TOUCH_STATE_REST))
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return true;
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final float x = ev.getX();
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switch (action) {
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case MotionEvent.ACTION_MOVE:
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final int xDiff = (int) Math.abs(mLastMotionX - x);
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if (xDiff > mTouchSlop)
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mTouchState = TOUCH_STATE_SCROLLING;
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break;
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case MotionEvent.ACTION_DOWN:
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mLastMotionX = x;
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mTouchState = mScroller.isFinished() ? TOUCH_STATE_REST
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: TOUCH_STATE_SCROLLING;
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break;
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case MotionEvent.ACTION_CANCEL:
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case MotionEvent.ACTION_UP:
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mTouchState = TOUCH_STATE_REST;
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break;
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}
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return mTouchState != TOUCH_STATE_REST;
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}
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- }

这是模仿qq的滑动实现,和tab不是一个思路,也比较美观实用可以借鉴