一.结构
由ViewPager,和简单的自定义PagerAdapter构成,ScheduledExecutorService实现自动循环。
二.代码
1.XML
主页
<?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"
android:layout_width="match_parent"
android:layout_height="300dp"
android:background="#000000">
</android.support.v4.view.ViewPager>
<LinearLayout
android:id="@+id/bottom_layout"
android:layout_width="match_parent"
android:layout_height="40dp"
android:background="#33000000"
android:orientation="vertical"
android:layout_alignBottom="@+id/viewpager">
<LinearLayout
android:id="@+id/dos_layout"
android:layout_width="match_parent"
android:layout_height="0dp"
android:layout_weight="1"
android:orientation="horizontal"
android:gravity="center">
</LinearLayout>
<TextView
android:id="@+id/title_textview"
android:layout_width="match_parent"
android:textColor="#ffffff"
android:layout_height="0dp"
android:layout_weight="1"
android:layout_gravity="center"
android:gravity="center"/>
</LinearLayout>
</RelativeLayout>
其中ViewPager用来放置图片,LinearLayout用来放置小圆点和图标标题。
另外附上两个小圆点的资源
dot_focused
<?xml version="1.0" encoding="utf-8"?>
<shape xmlns:android="http://schemas.android.com/apk/res/android"
android:shape="oval">
<solid android:color="#000000"/>
</shape>
dot_normal
<?xml version="1.0" encoding="utf-8"?>
<shape xmlns:android="http://schemas.android.com/apk/res/android"
android:shape="oval">
<solid android:color="#ffffff"/>
</shape>
2.JAVA
首先是自定义适配器,在内部声明了一个放置图片的数组
import android.content.Context;
import android.support.annotation.NonNull;
import android.support.v4.view.PagerAdapter;
import android.view.View;
import android.view.ViewGroup;
import android.widget.ImageView;
import java.util.ArrayList;
public class MyPagerAdapter extends PagerAdapter {
private Context context;
private ArrayList<ImageView> imageViews;
public MyPagerAdapter(Context context,ArrayList<ImageView>imageViews){
this.context = context;
this.imageViews = imageViews;
}
@Override
public int getCount() {
return Integer.MAX_VALUE;
}
@Override
public boolean isViewFromObject(@NonNull View view, @NonNull Object o) {
return view == o;
}
@NonNull
@Override
public Object instantiateItem(@NonNull ViewGroup container, int position) {
ImageView imageView = imageViews.get(position%imageViews.size());
container.addView(imageView);
return imageView;
}
@Override
public void destroyItem(@NonNull ViewGroup container, int position, @NonNull Object object) {
container.removeView((ImageView) object);
}
}
activity完成代码
import android.os.Bundle;
import android.os.Handler;
import android.os.Message;
import android.support.annotation.Nullable;
import android.support.v4.view.ViewPager;
import android.support.v7.app.AppCompatActivity;
import android.util.Log;
import android.view.View;
import android.view.ViewGroup;
import android.widget.ImageView;
import android.widget.LinearLayout;
import android.widget.TextView;
import com.example.adefault.banner.R;
import java.util.ArrayList;
import java.util.concurrent.Executors;
import java.util.concurrent.ScheduledExecutorService;
import java.util.concurrent.TimeUnit;
public class BannerTwoActivity extends AppCompatActivity implements View.OnClickListener {
private ViewPager viewPager;
private ArrayList<ImageView> imageViews;
private LinearLayout dos_layout;
private ArrayList<TextView>textViews;
private TextView textView;
private int[] imageIds =new int[]{
R.drawable.a,
R.drawable.b,
R.drawable.c,
R.drawable.d,
R.drawable.e,
};
private String[] titles = new String[]{
"第一张图片",
"第二张图片",
"第三张图片",
"第四张图片",
"第五张图片",
};
private ScheduledExecutorService scheduledExecutorService;
private int currentItem = 1;
private int oldItem = 0;
@Override
protected void onCreate(@Nullable Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_bannertwo);
bindViews();
initData();
setAdapter();
}
private void bindViews() {
viewPager = (ViewPager)findViewById(R.id.viewpager);
viewPager.setOnClickListener(this);
textView = (TextView)findViewById(R.id.title_textview);
textView.setText(titles[0]);
dos_layout = (LinearLayout)findViewById(R.id.dos_layout);
}
private void initData() {
imageViews = new ArrayList<ImageView>();
textViews = new ArrayList<TextView>();
for (int i = 0;i < imageIds.length;i++){
ImageView imageView = new ImageView(this);
imageView.setBackgroundResource(imageIds[i]);
imageView.setOnClickListener(this);
imageViews.add(imageView);
TextView textView = new TextView(this);
textView.setBackgroundResource(R.drawable.dot_normal);
if (i == 0){
textView.setBackgroundResource(R.drawable.dot_focused);
}
LinearLayout.LayoutParams layoutParams = new LinearLayout.LayoutParams(ViewGroup.LayoutParams.WRAP_CONTENT, ViewGroup.LayoutParams.WRAP_CONTENT);
layoutParams.height = 20;
layoutParams.width = 20;
layoutParams.setMargins(5,0,5,0);
textView.setLayoutParams(layoutParams);
textViews.add(textView);
dos_layout.addView(textView);
}
}
private void setAdapter() {
MyPagerAdapter pagerAdapter = new MyPagerAdapter(this,imageViews);
viewPager.setAdapter(pagerAdapter);
viewPager.setOnPageChangeListener(new ViewPager.OnPageChangeListener() {
@Override
public void onPageScrolled(int i, float v, int i1) {
}
@Override//选中某一页的监听
public void onPageSelected(int i) {
TextView currentTextView = textViews.get(i%textViews.size());
TextView oldTextView = textViews.get(oldItem);
currentTextView.setBackgroundResource(R.drawable.dot_focused);
oldTextView.setBackgroundResource(R.drawable.dot_normal);
oldItem = i%textViews.size();
currentItem = i;
}
@Override
public void onPageScrollStateChanged(int i) {
}
});
}
@Override
protected void onStart() {
super.onStart();
scheduledExecutorService = Executors.newSingleThreadScheduledExecutor();
scheduledExecutorService.scheduleWithFixedDelay(
new ViewPageTask(),
2,
2,
TimeUnit.SECONDS
);
}
@Override
public void onClick(View view) {
int index = viewPager.getCurrentItem()%imageIds.length;
Message message = new Message();
Bundle bundle = new Bundle();
bundle.putInt("index",index);
message.setData(bundle);
message.what = 1;
handler.sendMessage(message);
Log.e("胖虎","点击了:"+index);
}
//图片轮播任务
private class ViewPageTask implements Runnable{
@Override
public void run() {
handler.sendEmptyMessage(0);
}
}
private Handler handler = new Handler(){
@Override
public void handleMessage(Message msg) {
if (msg.what == 0){
viewPager.setCurrentItem(currentItem);
textView.setText(titles[(currentItem)%titles.length]);
currentItem += 1;
}else {
Bundle bundle = msg.getData();
int index = bundle.getInt("index");
}
};
};
@Override
protected void onStop() {
super.onStop();
if (scheduledExecutorService != null){
scheduledExecutorService.shutdown();
scheduledExecutorService = null;
}
}
}