布局
<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="match_parent"
android:layout_height="match_parent">
<android.support.v4.view.ViewPager
android:id="@+id/viewpager_vp"
android:layout_width="wrap_content"
android:layout_height="250dp"></android.support.v4.view.ViewPager>
<LinearLayout
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:background="#88000000"
android:orientation="vertical"
android:padding="8dp"
android:gravity="center_horizontal"
android:layout_alignBottom="@+id/viewpager_vp">
<TextView
android:id="@+id/ViewPager_tv"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:textColor="@android:color/white"
android:text="你是满天星"/>
<LinearLayout
android:id="@+id/ll_dot"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:orientation="horizontal">
<!--<View
android:layout_width="5dp"
android:layout_height="5dp"
android:background="@drawable/dot_normal"/>-->
</LinearLayout>
</LinearLayout>
</RelativeLayout>
实现类
package com.example.getname;
import android.os.Handler;
import android.os.Message;
import android.support.annotation.NonNull;
import android.support.v4.view.PagerAdapter;
import android.support.v4.view.ViewPager;
import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.view.MotionEvent;
import android.view.View;
import android.view.ViewGroup;
import android.widget.ImageView;
import android.widget.LinearLayout;
import android.widget.TextView;
import java.util.ArrayList;
public class MainActivity extends AppCompatActivity {
private LinearLayout ll_dot;
private TextView viewPager_tv;
private ViewPager viewpager_vp;
private ArrayList<ImageView> imageViews = new ArrayList<>();
private Handler handler = new Handler() {
@Override
public void handleMessage(Message msg) {
switch (msg.what) {
case 1:
//得到当前VIewPager和用户交互的item条目.VIewPager对象.getCurrentItem 333
int currentItem = viewpager_vp.getCurrentItem();
//设置ViewPager当前显示的界面,得到的ITem+1
viewpager_vp.setCurrentItem(currentItem + 1);
//通过静态方法sendEmptyMessageDelayed,延时重复执行命令.注意不是sendEmptyMessageAtTime 333
sendEmptyMessageDelayed(1, 3000);
break;
default:
break;
}
}
};
private int[] imageResIds = {
R.drawable.a,
R.drawable.b,
R.drawable.c,
R.drawable.d,
R.drawable.e,
};
private String[] descs = {
"巩俐不低俗，我就不能低俗",
"扑树又回来啦！再唱经典老歌引万人大合唱",
"揭秘北京电影如何升级",
"乐视网TV版大派送",
"热血屌丝的反杀",
};
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
init();
}
private void init() {
ll_dot = findViewById(R.id.ll_dot);
viewPager_tv = findViewById(R.id.ViewPager_tv);
viewpager_vp = findViewById(R.id.viewpager_vp);
for (int i = 0; i < imageResIds.length; i++) {
ImageView imageView = new ImageView(this);
imageView.setBackgroundResource(imageResIds[i]);
imageViews.add(imageView);
createDot(i);
}
viewpager_vp.setAdapter(new Myadapter());
viewpager_vp.addOnPageChangeListener(new ViewPager.OnPageChangeListener() {
@Override
public void onPageScrolled(int i, float v, int i1) {
int currentItem = viewpager_vp.getCurrentItem();
//通过得到的这个item,给text和点进行选中的设置.
changeTextandDot(currentItem % imageResIds.length);
}
@Override
public void onPageSelected(int i) {
}
@Override
public void onPageScrollStateChanged(int i) {
}
});
viewpager_vp.setCurrentItem(Integer.MAX_VALUE / 2 - 3);
handler.sendEmptyMessageDelayed(1, 3000);
ViewPagerTouchEvent();
}
class Myadapter extends PagerAdapter{
@Override
public int getCount() {
return Integer.MAX_VALUE;
}
@Override
public boolean isViewFromObject(@NonNull View view, @NonNull Object o) {
return view == o;
}
@Override
public Object instantiateItem(ViewGroup container, int position) {
//根据条目所在位置(利用Position),从ImageViews集合里获取相对应的ImageVIew图片.
ImageView imageView = imageViews.get(position % imageResIds.length);
//把得到ImageView对象,添加给VIewPager对象,也就是container,使用addView
container.addView(imageView);
//注意:你添加给VIewPager什么控件,就要返回该控件,给isViewFromObject进行比较判断,这里添加的是ImageView,返回的就是ImageView
return imageView;
}
@Override
public void destroyItem(ViewGroup container, int position, Object object) {
container.removeView((View) object);
}
}
private void changeTextandDot(int currentItem) {
viewPager_tv.setText(descs[currentItem]);
for(int x=0; x< imageResIds.length; x++){
//.getChildAt(x);拿到容器的子控件.得到VIew对象
View childAt = ll_dot.getChildAt(x);
//为View设置背景图片,,使用三元运算符.
childAt.setBackgroundResource(x==currentItem?R.drawable.dot_focus:R.drawable.dot_normal);
}
}
private void createDot(int i) {
View view = new View(this);
view.setBackgroundResource(R.drawable.dot_normal);
LinearLayout.LayoutParams layoutParams = new LinearLayout.LayoutParams(8,8);
layoutParams.leftMargin =8;
view.setLayoutParams(layoutParams);
ll_dot.addView(view);
}
public void ViewPagerTouchEvent() {
viewpager_vp.setOnTouchListener(new View.OnTouchListener() {
@Override
public boolean onTouch(View view, MotionEvent motionEvent) {
switch (motionEvent.getAction()) {
case MotionEvent.ACTION_DOWN:
//当时MotionEvent.ACTION_DOWN和ACTION_MOVE,就移除handler发送的message.removeMessages.333
handler.removeMessages(1);
break;
case MotionEvent.ACTION_MOVE:
handler.removeMessages(1);
break;
//当用户手松开时ACTION_UP,就继续使用sendEmptyMessageDelayed发送handler的消息.333
case MotionEvent.ACTION_UP:
handler.sendEmptyMessageDelayed(1, 3000);
default:
break;
}
return false;
}
});
}
@Override
protected void onDestroy() {
super.onDestroy();
handler.removeMessages(1);
}
}