我已经使用 android view pager 来显示图像和文本，现在我想要的是，如果用户没有更改图像，那么它应该在几秒钟后自动开始更改图像，当用户再次开始使用他的手指时，然后图像不应自动更改？
我尝试使用处理程序来创建延迟，但它对我不起作用？
请帮助任何人
public class SimpleImageViewerActivity extends Activity implements ViewPager.OnPageChangeListener{
private Handler handler;
ViewPager myPager;
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.imageslideshow);
MyPagerAdapter adapter = new MyPagerAdapter();
myPager = (ViewPager) findViewById(R.id.slideShowPager);
myPager.setAdapter(adapter);
myPager.setCurrentItem(0);
handler = new Handler();
myPager.setOnPageChangeListener(this);
}
private class MyPagerAdapter extends PagerAdapter {
public int getCount() {
return 5;
}
public Object instantiateItem(View collection, int position) {
LayoutInflater inflater = (LayoutInflater) collection.getContext()
.getSystemService(Context.LAYOUT_INFLATER_SERVICE);
int resId = 0;
switch (position) {
case 0:
resId = R.layout.farleft;
break;
case 1:
resId = R.layout.left;
break;
case 2:
resId = R.layout.middle;
break;
case 3:
resId = R.layout.right;
break;
case 4:
resId = R.layout.farright;
break;
}
View view = inflater.inflate(resId, null);
((ViewPager) collection).addView(view, 0);
return view;
}
@Override
public void destroyItem(View arg0, int arg1, Object arg2) {
((ViewPager) arg0).removeView((View) arg2);
}
@Override
public void finishUpdate(View arg0) {
// TODO Auto-generated method stub
}
@Override
public boolean isViewFromObject(View arg0, Object arg1) {
return arg0 == ((View) arg1);
}
@Override
public void restoreState(Parcelable arg0, ClassLoader arg1) {
// TODO Auto-generated method stub
}
@Override
public Parcelable saveState() {
// TODO Auto-generated method stub
return null;
}
@Override
public void startUpdate(View arg0) {
// TODO Auto-generated method stub
}
}
@Override
public void onPageScrollStateChanged(int arg0) {
// TODO Auto-generated method stub
}
@Override
public void onPageScrolled(int arg0, float arg1, int arg2) {
// TODO Auto-generated method stub
updateUI(arg2);
}
@Override
public void onPageSelected(int arg0) {
// TODO Auto-generated method stub
//updateUI(arg0);
}
public void onNothingSelected(AdapterView<?> adapterView) {
final int i =0;
adapterView.postDelayed(new Runnable(){
@Override
public void run() {
// TODO Auto-generated method stub
updateUI(i);
}
}, 5000);
Toast.makeText(this, "In nothing selected method",Toast.LENGTH_SHORT).show();
}
private void updateUI(final int fi) {
/* handler.post(new Runnable() {
public void run() {
gallery.setSelection(i);
viewPager.setCurrentItem(i);
//textView.setText("Photo #" + i);
}
});*/
handler.postDelayed(new Runnable() {
public void run() {
int i=fi;
int j = i;
myPager.setCurrentItem(j++);
System.out.println("Hello");
}
},1000);
}
}
使用javautil计时器并设置一个，在计时器结束时您可以使用
class UpdateTimeTask extends TimerTask {
public void run() {
//Code for the viewPager to change view
}
}
// Code to schedule the timer
timer = new Timer();
timer.schedule(new UpdateTimeTask(), 100, 200);
希望这有帮助，请使用 android 文档进行准确的 API 调用
<ViewPager>.setCurrentitem(i++%<MaxViews>)
就 UI 更新而言，您可以通过处理程序来完成，因此在timertask类中调用处理程序，您可以执行以下操作：
Timer timer=null;
static int time_tomove = 0;
class UpdateTimeTask extends TimerTask {
public void run() {
//Code for the viewPager to change view
System.out.println("The value of the time_tomove ");
time_tomove++;
Message msg = handler_timer.obtainMessage();
Bundle b = new Bundle();
b.putInt("time", time_tomove);
msg.setData(b);
handler_timer.sendMessage(msg);
}
}
public static Handler handler_timer = new Handler(){
@Override
public void handleMessage(Message msg) {
super.handleMessage(msg);
magazineHolder.setCurrentItem(time_tomove);
}
};
完成此操作后，您可以在 onresume 或 oncreate() 方法中调用以下两行
timer = new Timer();
timer.schedule(new UpdateTimeTask(), 100, 2000);
这是来自 Fragment 上下文，如果您处于 Activity 中，请删除
requireActivity()private var timer: Timer? = null
private var page = 0
private var maxPages = 4
// Use this method to setup your viewpager in your onCreate() or onActivityCreated() methods
fun setupViewPager(){
viewPager2.adapter = MyAdapter()
viewPager2.isUserInputEnabled = false
pageSwitcher(5)
}
fun pageSwitcher(seconds: Int) {
timer = Timer()
timer!!.scheduleAtFixedRate(RemindTask(), 0, seconds * 1000.toLong())
}
class RemindTask:TimerTask(){
override fun run() {
requireActivity().runOnUiThread {
if(page == maxPages){
page = 0
}else{
viewPager2.setCurrentItem(page++,true)
}
}
}
}
用于 kotlin 的简短扩展
private fun ViewPager2.postDelayScroll(totalPages: Int): Timer {
val timer = Timer()
var currentPage =0
timer.schedule(object : TimerTask() {
override fun run() {
handler.post {
if ( currentItem == totalPages -1) {
currentPage = 0;
}
[email protected](currentPage++, true);
}
}
},100,1000 * DELAY_IN_SECONDS)
return timer
}