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ViewPager做导航想不想有这样的效果：
比如说有四张图片，下面有四个圆点，当页面滑动的时候一个点变大一个点变小（或者是一个点变小一个点变大），等于说同时在执行两个动画。
package com.example.day_2014_10_17_viewpager;import java.util.ArrayList;
import java.util.HashMap;
import java.util.LinkedHashMap;import android.app.Activity;
import android.content.Context;
import android.os.Bundle;
import android.widget.ImageView;import com.nineoldandroids.view.ViewHelper;
import com.panpass.adapter.MyViewPagerAdapter;
import com.panpass.view.MyViewPager;
import com.panpass.view.MyViewPager.DiyPageScrollListener;public class MainActivity extends Activity {private Context mContext = this;private MyViewPager mViewPager;private ImageView imageView1, imageView2, imageView3, imageView4;private ArrayList<ImageView> mList;private HashMap<Integer, ImageView> mHashMap = new LinkedHashMap<Integer, ImageView>();private static final float SCALE_MAX = 0.55f;@Overrideprotected void onCreate(Bundle savedInstanceState) {super.onCreate(savedInstanceState);setContentView(R.layout.activity_main);mList = new ArrayList<ImageView>();ImageView img = new ImageView(mContext);img.setBackgroundResource(R.drawable.guide_page1);mList.add(img);img = new ImageView(mContext);img.setBackgroundResource(R.drawable.guide_page2);mList.add(img);img = new ImageView(mContext);img.setBackgroundResource(R.drawable.guide_page3);mList.add(img);img = new ImageView(mContext);img.setBackgroundResource(R.drawable.guide_page4);mList.add(img);mViewPager = (MyViewPager) findViewById(R.id.view_pager);mViewPager.setAdapter(new MyViewPagerAdapter(mList));imageView1 = (ImageView) findViewById(R.id.imageView1);imageView2 = (ImageView) findViewById(R.id.imageView2);imageView3 = (ImageView) findViewById(R.id.imageView3);imageView4 = (ImageView) findViewById(R.id.imageView4);ViewHelper.setScaleX(imageView2, SCALE_MAX);ViewHelper.setScaleY(imageView2, SCALE_MAX);ViewHelper.setScaleX(imageView3, SCALE_MAX);ViewHelper.setScaleY(imageView3, SCALE_MAX);ViewHelper.setScaleX(imageView4, SCALE_MAX);ViewHelper.setScaleY(imageView4, SCALE_MAX);mHashMap.put(0, imageView1);mHashMap.put(1, imageView2);mHashMap.put(2, imageView3);mHashMap.put(3, imageView4);mViewPager.setDiyOnPageScrollListener(new DiyPageScrollListener() {@Overridepublic void diyOnPageScrollListener(int position,float positionOffset, int positionOffsetPixels,boolean left, boolean right) {// 获取左边的ViewImageView mLeftImg = mHashMap.get(position);// 获取右边的ViewImageView mRightImg = mHashMap.get(position + 1);// 判断滑动的方向float mScaleRight;float mScaleLeft;/*** 注意事件： 1 注意你要很灵敏的判断ViewPager的切换方向是很难的，对于要求很高的应用来说是做不到了。 2* 不管是向左滑动还是向右滑动，他们有的都是同一种算法*/if (mRightImg != null) {/*** 缩小比例 如果手指从右到左的滑动（切换到后一个）：0.0~1.0，即从一半到最大* 如果手指从左到右的滑动（切换到前一个）：1.0~0，即从最大到一半*/mScaleRight = (1-SCALE_MAX) * positionOffset + SCALE_MAX;/*** x偏移量： 如果手指从右到左的滑动（切换到后一个）：0-720 如果手指从左到右的滑动（切换到前一个）：720-0*/ViewHelper.setScaleX(mRightImg, mScaleRight);ViewHelper.setScaleY(mRightImg, mScaleRight);}if (mLeftImg != null) {mScaleLeft = (1-SCALE_MAX) * (1 - positionOffset) + SCALE_MAX;/*** x偏移量： 如果手指从右到左的滑动（切换到后一个）：0-720 如果手指从左到右的滑动（切换到前一个）：720-0*/ViewHelper.setScaleX(mLeftImg, mScaleLeft);ViewHelper.setScaleY(mLeftImg, mScaleLeft);}}});}
}
package com.panpass.adapter;import java.util.ArrayList;import android.support.v4.view.PagerAdapter;
import android.view.View;
import android.view.ViewGroup;
import android.widget.ImageView;public class MyViewPagerAdapter extends PagerAdapter {private ArrayList<ImageView> imgList;public MyViewPagerAdapter(ArrayList<ImageView> imgList) {super();this.imgList = imgList;}@Overridepublic int getCount() {return imgList.size();}@Overridepublic Object instantiateItem(ViewGroup container, int position) {ImageView img = imgList.get(position);container.addView(img);return img;}@Overridepublic void destroyItem(ViewGroup container, int position, Object object) {container.removeView((ImageView)object);}@Overridepublic boolean isViewFromObject(View arg0, Object arg1) {return arg0 == (View)arg1;}}
package com.panpass.view;import android.content.Context;
import android.support.v4.view.ViewPager;
import android.util.AttributeSet;public class MyViewPager extends ViewPager {private boolean left = false; private boolean right = false; private boolean isScrolling = false; private int lastValue = -1; private ChangeViewCallback changeViewCallback = null; public MyViewPager(Context context, AttributeSet attrs) { super(context, attrs); init(); } public MyViewPager(Context context) { super(context); init(); } private DiyPageScrollListener listener1;public interface DiyPageScrollListener{void diyOnPageScrollListener(int position, float positionOffset, int positionOffsetPixels,boolean left,boolean right);}public void setDiyOnPageScrollListener(DiyPageScrollListener listener){this.listener1 = listener;}@Overrideprotected void onPageScrolled(int position, float positionOffset, int positionOffsetPixels) {listener1.diyOnPageScrollListener(position, positionOffset, positionOffsetPixels,left,right);super.onPageScrolled(position, positionOffset, positionOffsetPixels);}/** * init method . */ private void init() {
// setOnPageChangeListener(listener); } /** * listener ,to get move direction . */ public OnPageChangeListener listener = new OnPageChangeListener() { @Override public void onPageScrollStateChanged(int arg0) { if (arg0 == 1) { isScrolling = true; } else { isScrolling = false; } if (arg0 == 2) { if(changeViewCallback!=null){ changeViewCallback.changeView(left, right); } right = left = false; } } @Override public void onPageScrolled(int arg0, float arg1, int arg2) { if (isScrolling) { if (lastValue > arg2) { // 递减，向右侧滑动 right = true; left = false; } else if (lastValue < arg2) { // 递减，向右侧滑动 right = false; left = true; } else if (lastValue == arg2) { right = left = false; } } lastValue = arg2; } @Override public void onPageSelected(int arg0) { if(changeViewCallback!=null){ changeViewCallback.getCurrentPageIndex(arg0); } } }; /** * 得到是否向右侧滑动 * @return true 为右滑动 */ public boolean getMoveRight(){ return right; } /** * 得到是否向左侧滑动 * @return true 为左做滑动 */ public boolean getMoveLeft(){ return left; } /** * 滑动状态改变回调 * @author zxy * */ public interface ChangeViewCallback{ public void changeView(boolean left,boolean right); public void getCurrentPageIndex(int index); } public void setChangeViewCallback(ChangeViewCallback callback){ changeViewCallback = callback; } }
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"xmlns:tools="http://schemas.android.com/tools"android:layout_width="match_parent"android:layout_height="match_parent" ><com.panpass.view.MyViewPagerandroid:id="@+id/view_pager"android:layout_width="match_parent"android:layout_height="match_parent" /><LinearLayoutandroid:layout_width="match_parent"android:layout_height="wrap_content"android:layout_alignParentBottom="true"android:layout_centerHorizontal="true"android:layout_marginBottom="50dp"android:gravity="center" ><ImageViewandroid:id="@+id/imageView1"android:layout_width="wrap_content"android:layout_height="wrap_content"android:src="@drawable/banner_circle_big" /><ImageViewandroid:id="@+id/imageView2"android:layout_width="wrap_content"android:layout_height="wrap_content"android:layout_marginLeft="15dp"android:src="@drawable/banner_circle_big" /><ImageViewandroid:id="@+id/imageView3"android:layout_width="wrap_content"android:layout_height="wrap_content"android:layout_marginLeft="15dp"android:src="@drawable/banner_circle_big" /><ImageViewandroid:id="@+id/imageView4"android:layout_width="wrap_content"android:layout_height="wrap_content"android:layout_marginLeft="15dp"android:src="@drawable/banner_circle_big" /></LinearLayout></RelativeLayout>这篇关于Android ViewPager导航------平凡中有奇迹的文章就介绍到这儿，希望我们推荐的文章对编程师们有所帮助！
