android 左右滑屏
最近比较闲，想起墨迹左右滑屏的效果该如何实现，如是在网上搜索资料，都没看到理想的效果，于是参照别人的例子自己加以修改，最终效果还行。左右滑屏是通过ViewGroup结合手势划屏来实现，代码如下：
package com.scroll.test;import com.scroll.test.R;import android.app.Activity;import android.os.Bundle;import android.util.Log;import android.view.View;import android.view.View.OnClickListener;import android.view.View.OnFocusChangeListener;import android.widget.Button;public class ScrollLayoutTest extends Activity {private ScrollLayout sl;private Button btn1;private PageControlView pageControlView;@Overridepublic void onCreate(Bundle savedInstanceState) {super.onCreate(savedInstanceState);setContentView(R.layout.main);sl = (ScrollLayout) findViewById(R.id.ScrollLayoutTest);pageControlView = (PageControlView) findViewById(R.id.pageControl);btn1 = (Button) findViewById(R.id.btn1);btn1.setOnClickListener(new OnClickListener() {@Overridepublic void onClick(View v) {sl.snapToScreen(1);}});sl.setOnFocusChangeListener(new OnFocusChangeListener() {@Overridepublic void onFocusChange(View v, boolean hasFocus) {int i = v.getVisibility();Log.v("=sl.i=", i + "=");}});Log.v("=sl.getCurScreen()=", sl.getCurScreen() + "=");pageControlView.bindScrollLayout(sl);}}?
package com.scroll.test;import android.content.Context;import android.graphics.Canvas;import android.util.AttributeSet;import android.util.Log;import android.view.MotionEvent;import android.view.VelocityTracker;import android.view.View;import android.view.ViewConfiguration;import android.view.ViewGroup;import android.widget.Scroller;/** * 仿Launcher中的WorkSapce，可以左右滑动切换屏幕的类 * * * */public class ScrollLayout extends ViewGroup {private static final String TAG = "ScrollLayout";private Scroller mScroller;private VelocityTracker mVelocityTracker;private int mCurScreen;private int mDefaultScreen = 0;private static final int TOUCH_STATE_REST = 0;private static final int TOUCH_STATE_SCROLLING = 1;private static final int SNAP_VELOCITY = 600;private int mTouchState = TOUCH_STATE_REST;private int mTouchSlop;private float mLastMotionX;private float mLastMotionY;public ScrollLayout(Context context, AttributeSet attrs) {this(context, attrs, 0);// TODO Auto-generated constructor stub}public ScrollLayout(Context context, AttributeSet attrs, int defStyle) {super(context, attrs, defStyle);// TODO Auto-generated constructor stubmScroller = new Scroller(context);mCurScreen = mDefaultScreen;mTouchSlop = ViewConfiguration.get(getContext()).getScaledTouchSlop();}@Overrideprotected void onLayout(boolean changed, int l, int t, int r, int b) {// TODO Auto-generated method stubif (changed) {int childLeft = 0;final int childCount = getChildCount();for (int i = 0; i < childCount; i++) {final View childView = getChildAt(i);if (childView.getVisibility() != View.GONE) {final int childWidth = childView.getMeasuredWidth();childView.layout(childLeft, 0, childLeft + childWidth,childView.getMeasuredHeight());childLeft += childWidth;}}}}@Overrideprotected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {Log.e(TAG, "onMeasure");super.onMeasure(widthMeasureSpec, heightMeasureSpec);final int width = MeasureSpec.getSize(widthMeasureSpec);final int widthMode = MeasureSpec.getMode(widthMeasureSpec);if (widthMode != MeasureSpec.EXACTLY) {throw new IllegalStateException("ScrollLayout only canmCurScreen run at EXACTLY mode!");}final int heightMode = MeasureSpec.getMode(heightMeasureSpec);if (heightMode != MeasureSpec.EXACTLY) {throw new IllegalStateException("ScrollLayout only can run at EXACTLY mode!");}// The children are given the same width and height as the scrollLayoutfinal int count = getChildCount();for (int i = 0; i < count; i++) {getChildAt(i).measure(widthMeasureSpec, heightMeasureSpec);}// Log.e(TAG, "moving to screen "+mCurScreen);scrollTo(mCurScreen * width, 0);}/** * According to the position of current layout scroll to the destination * page. */public void snapToDestination() {final int screenWidth = getWidth();final int destScreen = (getScrollX() + screenWidth / 2) / screenWidth;snapToScreen(destScreen);// 设置循环滑屏方法一：// 设置使循环（5表示总共有多少屏）/*if (destScreen == 0) {setToScreen(5);} else if (destScreen == 5) {setToScreen(0);} else {// 设置不循环snapToScreen(destScreen);}*/}public void snapToScreen(int whichScreen) {// get the valid layout pagewhichScreen = Math.max(0, Math.min(whichScreen, getChildCount() - 1));if (getScrollX() != (whichScreen * getWidth())) {final int delta = whichScreen * getWidth() - getScrollX();mScroller.startScroll(getScrollX(), 0, delta, 0,Math.abs(delta) * 2);mCurScreen = whichScreen;onScreenChangeListener.onScreenChange(mCurScreen);invalidate(); // Redraw the layout}}public void setToScreen(int whichScreen) {whichScreen = Math.max(0, Math.min(whichScreen, getChildCount() - 1));mCurScreen = whichScreen;scrollTo(whichScreen * getWidth(), 0);//设置循环滑屏方法二：//onScreenChangeListener.onScreenChange(mCurScreen);}public int getCurScreen() {return mCurScreen;}@Overridepublic void computeScroll() {// TODO Auto-generated method stubif (mScroller.computeScrollOffset()) {scrollTo(mScroller.getCurrX(), mScroller.getCurrY());postInvalidate();}}@Overridepublic boolean onTouchEvent(MotionEvent event) {// TODO Auto-generated method stubif (mVelocityTracker == null) {mVelocityTracker = VelocityTracker.obtain();}mVelocityTracker.addMovement(event);final int action = event.getAction();final float x = event.getX();final float y = event.getY();switch (action) {case MotionEvent.ACTION_DOWN:Log.e(TAG, "event down!");if (!mScroller.isFinished()) {mScroller.abortAnimation();}mLastMotionX = x;break;case MotionEvent.ACTION_MOVE:int deltaX = (int) (mLastMotionX - x);mLastMotionX = x;scrollBy(deltaX, 0);break;case MotionEvent.ACTION_UP:Log.e(TAG, "event : up");// if (mTouchState == TOUCH_STATE_SCROLLING) {final VelocityTracker velocityTracker = mVelocityTracker;velocityTracker.computeCurrentVelocity(1000);int velocityX = (int) velocityTracker.getXVelocity();Log.e(TAG, "velocityX:" + velocityX);if (velocityX > SNAP_VELOCITY && mCurScreen > 0) {// Fling enough to move left// onScreenChangeListener.onScreenChange(mCurScreen - 1);Log.e(TAG, "snap left");snapToScreen(mCurScreen - 1);} else if (velocityX < -SNAP_VELOCITY&& mCurScreen < getChildCount() - 1) {// Fling enough to move rightLog.e(TAG, "snap right");// onScreenChangeListener.onScreenChange(mCurScreen + 1);snapToScreen(mCurScreen + 1);} else {snapToDestination();}if (mVelocityTracker != null) {mVelocityTracker.recycle();mVelocityTracker = null;}// }mTouchState = TOUCH_STATE_REST;break;case MotionEvent.ACTION_CANCEL:mTouchState = TOUCH_STATE_REST;break;}return true;}@Overridepublic boolean onInterceptTouchEvent(MotionEvent ev) {// TODO Auto-generated method stubLog.e(TAG, "onInterceptTouchEvent-slop:" + mTouchSlop);final int action = ev.getAction();if ((action == MotionEvent.ACTION_MOVE)&& (mTouchState != TOUCH_STATE_REST)) {return true;}final float x = ev.getX();final float y = ev.getY();switch (action) {case MotionEvent.ACTION_MOVE:final int xDiff = (int) Math.abs(mLastMotionX - x);if (xDiff > mTouchSlop) {mTouchState = TOUCH_STATE_SCROLLING;}break;case MotionEvent.ACTION_DOWN:mLastMotionX = x;mLastMotionY = y;mTouchState = mScroller.isFinished() ? TOUCH_STATE_REST: TOUCH_STATE_SCROLLING;break;case MotionEvent.ACTION_CANCEL:case MotionEvent.ACTION_UP:mTouchState = TOUCH_STATE_REST;break;}return mTouchState != TOUCH_STATE_REST;}// 监听页面变动public interface OnScreenChangeListener {void onScreenChange(int currentIndex);}private OnScreenChangeListener onScreenChangeListener;public void setOnScreenChangeListener(OnScreenChangeListener onScreenChangeListener) {this.onScreenChangeListener = onScreenChangeListener;}}?
package com.scroll.test;import com.scroll.test.ScrollLayout.OnScreenChangeListener;import com.scroll.test.R;import android.R.integer;import android.content.Context;import android.util.AttributeSet;import android.util.Log;import android.widget.FrameLayout;import android.widget.ImageView;import android.widget.LinearLayout;public class PageControlView extends LinearLayout {private Context context;private int count;public PageControlView(Context context) {super(context);this.context = context;}public PageControlView(Context context, AttributeSet attrs) {super(context, attrs);this.context = context;}public void bindScrollLayout(ScrollLayout scrollLayout) {this.count = scrollLayout.getChildCount();Log.v("=count==", count + "=");// 初始化第一屏generatePageControl(0);scrollLayout.setOnScreenChangeListener(new OnScreenChangeListener() {@Overridepublic void onScreenChange(int currentIndex) {generatePageControl(currentIndex);}});}private void generatePageControl(int currentIndex) {this.removeAllViews();for (int i = 0; i < this.count; i++) {Log.v("=i==", i + "=");ImageView imageView = new ImageView(context);if (i == currentIndex) {imageView.setImageResource(R.drawable.page_indicator_focused);} else {imageView.setImageResource(R.drawable.page_indicator);}this.addView(imageView);}}}?
<?xml version="1.0" encoding="utf-8"?><RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"android:layout_width="fill_parent" android:layout_height="fill_parent"><com.scroll.test.ScrollLayoutxmlns:android="http://schemas.android.com/apk/res/android" android:id="@+id/ScrollLayoutTest"android:layout_width="fill_parent" android:layout_height="fill_parent"><LinearLayout android:background="#FF00"android:layout_width="fill_parent" android:layout_height="fill_parent"></LinearLayout><FrameLayout android:background="#F0F0"android:layout_width="fill_parent" android:layout_height="fill_parent"></FrameLayout><FrameLayout android:background="#F00F"android:layout_width="fill_parent" android:layout_height="fill_parent"></FrameLayout><LinearLayout android:background="#FF00"android:layout_width="fill_parent" android:layout_height="fill_parent"><Button android:layout_width="wrap_content"android:layout_height="wrap_content" android:text="Button1"android:id="@+id/btn1" /></LinearLayout><LinearLayout android:layout_width="wrap_content"android:layout_height="wrap_content"><Button android:layout_width="wrap_content"android:layout_height="wrap_content" android:text="Button2" /></LinearLayout></com.scroll.test.ScrollLayout><com.scroll.test.PageControlViewandroid:id="@+id/pageControl" android:layout_width="wrap_content"android:layout_height="wrap_content" android:layout_centerHorizontal="true"android:layout_alignParentBottom="true"></com.scroll.test.PageControlView></RelativeLayout>
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?? 附近是具体的源码。
，没用android-support-v4就实现了这个效果 2 楼 wwwjiandan 2012-05-31 现在有许多软件在安装后初次打开时,会有图片指示的帮助，也是左右滑动，好像大都是用ViewPager实现的