今天给大家介绍一下如何实现androd主页面的左右拖动效果。实现起来很简单,就是使用ViewFlipper来将您要来回拖动的View装在一起,然 后与GestureDetector手势识别类来联动,确定要显示哪个View,加上一点点动画效果即可。比如当手指向左快速滑动时跳转到上一个 View,手指向右快速滑动时跳转到下一个View,本例中使用图片作为各个View的页面,实现左右快速滑动显示不同的图片。
转自 http://www.ideasandroid.com/archives/414
<linearlayout android:layout_height="fill_parent" android:layout_width="fill_parent" android:orientation="vertical" xmlns:android="http://schemas.android.com/apk/res/android"> <viewflipper android:id="@+id/flipper" android:layout_below="@+id/CockpitLayout" android:layout_height="fill_parent" android:layout_width="fill_parent"> <include android:id="@+id/firstlayout" layout="@layout/first"></include> <include android:id="@+id/secondlayout" layout="@layout/second"></include> <include android:id="@+id/thirdlayout" layout="@layout/third"></include> <include android:id="@+id/fourthlayout" layout="@layout/fourth"></include> </viewflipper> </linearlayout>
<linearlayout android:gravity="center_vertical" android:layout_height="fill_parent" android:layout_width="fill_parent" xmlns:android="http://schemas.android.com/apk/res/android"> <imageview android:layout_height="wrap_content" android:layout_width="wrap_content" android:src="@drawable/v1"> </imageview> </linearlayout>
package com.ideasandroid.demo; import android.app.Activity; import android.os.Bundle; import android.view.GestureDetector; import android.view.MotionEvent; import android.view.View; import android.view.GestureDetector.OnGestureListener; import android.view.View.OnTouchListener; import android.view.animation.AccelerateInterpolator; import android.view.animation.Animation; import android.view.animation.TranslateAnimation; import android.widget.ViewFlipper; public class ViewFlipperDemo extends Activity implements OnGestureListener,OnTouchListener{ private ViewFlipper mFlipper; GestureDetector mGestureDetector; private int mCurrentLayoutState; private static final int FLING_MIN_DISTANCE = 100; private static final int FLING_MIN_VELOCITY = 200; @Override public void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.main); mFlipper = (ViewFlipper) findViewById(R.id.flipper); //注册一个用于手势识别的类 mGestureDetector = new GestureDetector(this); //给mFlipper设置一个listener mFlipper.setOnTouchListener(this); mCurrentLayoutState = 0; //允许长按住ViewFlipper,这样才能识别拖动等手势 mFlipper.setLongClickable(true); } /** * 此方法在本例中未用到,可以指定跳转到某个页面 * @param switchTo */ public void switchLayoutStateTo(int switchTo) { while (mCurrentLayoutState != switchTo) { if (mCurrentLayoutState > switchTo) { mCurrentLayoutState--; mFlipper.setInAnimation(inFromLeftAnimation()); mFlipper.setOutAnimation(outToRightAnimation()); mFlipper.showPrevious(); } else { mCurrentLayoutState++; mFlipper.setInAnimation(inFromRightAnimation()); mFlipper.setOutAnimation(outToLeftAnimation()); mFlipper.showNext(); } } ; } /** * 定义从右侧进入的动画效果 * @return */ protected Animation inFromRightAnimation() { Animation inFromRight = new TranslateAnimation( Animation.RELATIVE_TO_PARENT, +1.0f, Animation.RELATIVE_TO_PARENT, 0.0f, Animation.RELATIVE_TO_PARENT, 0.0f, Animation.RELATIVE_TO_PARENT, 0.0f); inFromRight.setDuration(500); inFromRight.setInterpolator(new AccelerateInterpolator()); return inFromRight; } /** * 定义从左侧退出的动画效果 * @return */ protected Animation outToLeftAnimation() { Animation outtoLeft = new TranslateAnimation( Animation.RELATIVE_TO_PARENT, 0.0f, Animation.RELATIVE_TO_PARENT, -1.0f, Animation.RELATIVE_TO_PARENT, 0.0f, Animation.RELATIVE_TO_PARENT, 0.0f); outtoLeft.setDuration(500); outtoLeft.setInterpolator(new AccelerateInterpolator()); return outtoLeft; } /** * 定义从左侧进入的动画效果 * @return */ protected Animation inFromLeftAnimation() { Animation inFromLeft = new TranslateAnimation( Animation.RELATIVE_TO_PARENT, -1.0f, Animation.RELATIVE_TO_PARENT, 0.0f, Animation.RELATIVE_TO_PARENT, 0.0f, Animation.RELATIVE_TO_PARENT, 0.0f); inFromLeft.setDuration(500); inFromLeft.setInterpolator(new AccelerateInterpolator()); return inFromLeft; } /** * 定义从右侧退出时的动画效果 * @return */ protected Animation outToRightAnimation() { Animation outtoRight = new TranslateAnimation( Animation.RELATIVE_TO_PARENT, 0.0f, Animation.RELATIVE_TO_PARENT, +1.0f, Animation.RELATIVE_TO_PARENT, 0.0f, Animation.RELATIVE_TO_PARENT, 0.0f); outtoRight.setDuration(500); outtoRight.setInterpolator(new AccelerateInterpolator()); return outtoRight; } public boolean onDown(MotionEvent e) { // TODO Auto-generated method stub return false; } /* * 用户按下触摸屏、快速移动后松开即触发这个事件 * e1:第1个ACTION_DOWN MotionEvent * e2:最后一个ACTION_MOVE MotionEvent * velocityX:X轴上的移动速度,像素/秒 * velocityY:Y轴上的移动速度,像素/秒 * 触发条件 : * X轴的坐标位移大于FLING_MIN_DISTANCE,且移动速度大于FLING_MIN_VELOCITY个像素/秒 */ public boolean onFling(MotionEvent e1, MotionEvent e2, float velocityX, float velocityY) { if (e1.getX() - e2.getX() > FLING_MIN_DISTANCE && Math.abs(velocityX) > FLING_MIN_VELOCITY) { // 当像左侧滑动的时候 //设置View进入屏幕时候使用的动画 mFlipper.setInAnimation(inFromRightAnimation()); //设置View退出屏幕时候使用的动画 mFlipper.setOutAnimation(outToLeftAnimation()); mFlipper.showNext(); } else if (e2.getX() - e1.getX() > FLING_MIN_DISTANCE && Math.abs(velocityX) > FLING_MIN_VELOCITY) { // 当像右侧滑动的时候 mFlipper.setInAnimation(inFromLeftAnimation()); mFlipper.setOutAnimation(outToRightAnimation()); mFlipper.showPrevious(); } return false; } public void onLongPress(MotionEvent e) { // TODO Auto-generated method stub } public boolean onScroll(MotionEvent e1, MotionEvent e2, float distanceX, float distanceY) { return false; } public void onShowPress(MotionEvent e) { // TODO Auto-generated method stub } public boolean onSingleTapUp(MotionEvent e) { // TODO Auto-generated method stub return false; } public boolean onTouch(View v, MotionEvent event) { // 一定要将触屏事件交给手势识别类去处理(自己处理会很麻烦的) return mGestureDetector.onTouchEvent(event); } }