Android ViewPager导航------平凡中有奇迹
浏览数：19 /
时间：2015年06月11日
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;
@Override
protected 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() {
@Override
public void diyOnPageScrollListener(int position,
float positionOffset, int positionOffsetPixels,
boolean left, boolean right) {
// 获取左边的View
ImageView mLeftImg = mHashMap.get(position);
// 获取右边的View
ImageView 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;
}
@Override
public int getCount() {
return imgList.size();
}
@Override
public Object instantiateItem(ViewGroup container, int position) {
ImageView img = imgList.get(position);
container.addView(img);
return img;
}
@Override
public void destroyItem(ViewGroup container, int position, Object object) {
container.removeView((ImageView)object);
}
@Override
public 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;
}
@Override
protected 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.MyViewPager
android:id="@+id/view_pager"
android:layout_width="match_parent"
android:layout_height="match_parent" />
<LinearLayout
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:layout_alignParentBottom="true"
android:layout_centerHorizontal="true"
android:layout_marginBottom="50dp"
android:gravity="center" >
<ImageView
android:id="@+id/imageView1"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:src="@drawable/banner_circle_big" />
<ImageView
android:id="@+id/imageView2"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_marginLeft="15dp"
android:src="@drawable/banner_circle_big" />
<ImageView
android:id="@+id/imageView3"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_marginLeft="15dp"
android:src="@drawable/banner_circle_big" />
<ImageView
android: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>郑重声明：本站内容如果来自互联网及其他传播媒体，其版权均属原媒体及文章作者所有。转载目的在于传递更多信息及用于网络分享，并不代表本站赞同其观点和对其真实性负责，也不构成任何其他建议。
