时间：2021-11-23 11:45:35 | 栏目：Android代码 | 点击：次
android新特性页面，ViewPager拖拽到最后一页再拖拽打开其他Activity.实现的方式有很多，效果比较好的就是到了最后一页再拖拽出现禁止蓝色条时再跳转activity
方式一：拿到ViewPager的边界条EdgeEffectCompat，判断是否到了边界（获取EdgeEffectCompat通过反射，方法来自网络最后边会给出原文）
/**
* 初始化view
*/
private void initView(){
pager = (ViewPager) findViewById(R.id.help_viewpages);
try {
Field leftEdgeField = pager.getClass().getDeclaredField("mLeftEdge");
Field rightEdgeField = pager.getClass().getDeclaredField("mRightEdge");
if (leftEdgeField != null && rightEdgeField != null) {
leftEdgeField.setAccessible(true);
rightEdgeField.setAccessible(true);
leftEdge = (EdgeEffectCompat) leftEdgeField.get(pager);
rightEdge = (EdgeEffectCompat) rightEdgeField.get(pager);
}
} catch (Exception e) {
e.printStackTrace();
}
pager.setOnPageChangeListener(new OnPageChangeListener() {
@Override
public void onPageScrollStateChanged(int arg0) {
if(rightEdge!=null&&!rightEdge.isFinished()){//到了最后一张并且还继续拖动，出现蓝色限制边条了
startActivity(new Intent(HelpActivity.this, MainActivity.class));
HelpActivity.this.finish();
}
}
@Override
public void onPageSelected(int arg0) {
}
@Override
public void onPageScrolled(int arg0, float arg1, int arg2) {
}
});
方法二：也是在OnPageChangeListener里判断当前滚动的页数是不是最后一页
pager.setOnPageChangeListener(new OnPageChangeListener() {
@Override
public void onPageSelected(int arg0) {
}
@Override
public void onPageScrolled(int arg0, float arg1, int arg2) {
}
@Override
public void onPageScrollStateChanged(int arg0) {
//判断当前页数是否==总页数
}
});
在此小编推荐方法一，方法二需要判断PageScrollStateChanged(int arg0)的滚动状态，也可以实现一样的效果
转载高手ViewPager在拖拽到左边和右边的时候，禁止显示黄色或者蓝色的渐变图片的解决方法（以备自己以后查阅）
package com.example.viewpagertest;
import java.lang.reflect.Field;
import java.util.ArrayList;
import java.util.List;
import android.app.Activity;
import android.os.Bundle;
import android.support.v4.view.PagerAdapter;
import android.support.v4.view.ViewPager;
import android.support.v4.view.ViewPager.OnPageChangeListener;
import android.support.v4.widget.EdgeEffectCompat;
import android.view.View;
import android.view.ViewGroup;
import android.widget.ImageView;
public class MainActivity extends Activity implements OnPageChangeListener {
private ViewPager viewpager;
private List<ImageView> views;
private EdgeEffectCompat leftEdge;
private EdgeEffectCompat rightEdge;
private int[] ids = {R.drawable.iframe_4,R.drawable.iframe_5,R.drawable.iframe_6,R.drawable.iframe_7,R.drawable.iframe_8};
private MyAdapter adapter;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
initView();
}
private void initView() {
viewpager = (ViewPager) findViewById(R.id.viewpager);
initViewPager();
initData();
}
private void initData() {
views = new ArrayList<ImageView>();
for(int i=0;i<ids.length;i++){
ImageView iv = new ImageView(this);
iv.setImageResource(ids[i]);
views.add(iv);
}
adapter = new MyAdapter();
viewpager.setAdapter(adapter);
viewpager.setOnPageChangeListener(this);
}
class MyAdapter extends PagerAdapter{
@Override
public int getCount() {
return views.size();
}
@Override
public boolean isViewFromObject(View arg0, Object arg1) {
return arg0==arg1;
}
@Override
public void destroyItem(ViewGroup container, int position, Object object) {
((ViewPager)container).removeView(views.get(position));
}
@Override
public Object instantiateItem(ViewGroup container, int position) {
((ViewPager)container).addView(views.get(position));
return views.get(position);
}
}
@Override
public void onPageScrollStateChanged(int arg0) {
}
@Override
public void onPageScrolled(int arg0, float arg1, int arg2) {
if (leftEdge != null && rightEdge != null) {
leftEdge.finish();
rightEdge.finish();
leftEdge.setSize(0, 0);
rightEdge.setSize(0, 0);
}
}
@Override
public void onPageSelected(int arg0) {
}
private void initViewPager() {
try {
Field leftEdgeField = viewpager.getClass().getDeclaredField("mLeftEdge");
Field rightEdgeField = viewpager.getClass().getDeclaredField("mRightEdge");
if (leftEdgeField != null && rightEdgeField != null) {
leftEdgeField.setAccessible(true);
rightEdgeField.setAccessible(true);
leftEdge = (EdgeEffectCompat) leftEdgeField.get(viewpager);
rightEdge = (EdgeEffectCompat) rightEdgeField.get(viewpager);
}
} catch (Exception e) {
e.printStackTrace();
}
}
}