我在我的应用程序中实现了一个ViewPager，其中包含两张幻灯片。我可以从first slide转到second slide并反转。但我在这里有一个特例。如果用户从First Slide转到Second Slide。他不应该回到First slide。我需要在进入First Slide后禁用返回Second Slide。
这是我的代码：
public class BotConnectionDialog extends DialogFragment {
private RelativeLayout toolbar;
private ImageView toolbarCloseButton;
private View layoutView;
private ViewPager viewPager;
private BotConnectionDialogAdapter myViewPagerAdapter;
private LinearLayout dotsLayout;
private TextView[] dots;
int width, height;
DisplayMetrics metrics;
private int[] layouts;
private final String TAG = BotConnectionDialog.class.getSimpleName();
private Button btnSkip, btnNext;
View.OnClickListener myListener = new View.OnClickListener() {
@Override
public void onClick(View view) {
Handler handler = new Handler();
handler.post(new Runnable() {
@Override
public void run() {
getActivity().getSupportFragmentManager().popBackStackImmediate();
}
});
}
};
@Override
public void onCreate(@Nullable Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setStyle(DialogFragment.STYLE_NORMAL, android.R.style.Theme_Black_NoTitleBar_Fullscreen);
}
@Nullable
@Override
public View onCreateView(LayoutInflater inflater, @Nullable ViewGroup container, @Nullable Bundle savedInstanceState) {
View rootView = inflater.inflate(R.layout.botconnection_layout, container, false);
Typeface typeface = Typeface.createFromAsset(getActivity().getAssets(), "fonts/corbert.otf");
toolbar = (RelativeLayout) rootView.findViewById(R.id.customAppBarLayout);
toolbar.setBackgroundColor(Color.parseColor("#00000000"));
toolbarCloseButton = (ImageView) rootView.findViewById(R.id.toolbarCloseButton);
toolbarCloseButton.setOnClickListener(myListener);
viewPager = (ViewPager) rootView.findViewById(R.id.view_pager);
dotsLayout = (LinearLayout) rootView.findViewById(R.id.layoutDots);
btnSkip = (Button) rootView.findViewById(R.id.btn_skip);
btnSkip.setTypeface(typeface);
btnNext = (Button) rootView.findViewById(R.id.btn_next);
btnNext.setTypeface(typeface);
metrics = getResources().getDisplayMetrics();
width = metrics.widthPixels;
height = metrics.heightPixels;
// layouts of all welcome sliders
// add few more layouts if you want
layouts = new int[]{
R.layout.slide1,
R.layout.slide2};
// adding bottom dots
addBottomDots(0);
myViewPagerAdapter = new BotConnectionDialogAdapter();
viewPager.setAdapter(myViewPagerAdapter);
viewPager.addOnPageChangeListener(viewPagerPageChangeListener);
btnNext.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
// checking for last page
// if last page home screen will be launched
int current = getItem(+1);
if (current < layouts.length) {
// move to next screen
viewPager.setCurrentItem(current);
} else {
}
}
});
return rootView;
}
private void addBottomDots(int currentPage) {
dots = new TextView[layouts.length];
int[] colorsActive = getResources().getIntArray(R.array.array_dot_active);
int[] colorsInactive = getResources().getIntArray(R.array.array_dot_inactive);
dotsLayout.removeAllViews();
for (int i = 0; i < dots.length; i++) {
dots[i] = new TextView(getActivity());
dots[i].setText(Html.fromHtml("•"));
dots[i].setTextSize(35);
dots[i].setTextColor(colorsInactive[currentPage]);
dotsLayout.addView(dots[i]);
}
if (dots.length > 0)
dots[currentPage].setTextColor(colorsActive[currentPage]);
}
private int getItem(int i) {
return viewPager.getCurrentItem() + i;
}
// viewpager change listener
ViewPager.OnPageChangeListener viewPagerPageChangeListener = new ViewPager.OnPageChangeListener() {
@Override
public void onPageSelected(int position) {
addBottomDots(position);
// changing the next button text 'NEXT' / 'GOT IT'
if (position == layouts.length - 1) {
// last page. make button text to GOT IT
btnNext.setText(getString(R.string.start));
btnSkip.setVisibility(View.GONE);
/**
* bluetooth connection the bot
*/
Toast.makeText(getActivity(), "Finished", Toast.LENGTH_SHORT).show();
} else {
// still pages are left
btnNext.setText(getString(R.string.next));
btnSkip.setVisibility(View.VISIBLE);
/**
* First page
*/
Toast.makeText(getActivity(), "2nd page", Toast.LENGTH_SHORT).show();
}
}
@Override
public void onPageScrolled(int arg0, float arg1, int arg2) {
}
@Override
public void onPageScrollStateChanged(int arg0) {
}
};
@NonNull
@Override
public Dialog onCreateDialog(Bundle savedInstanceState) {
Dialog dialog = super.onCreateDialog(savedInstanceState);
//dialog.getWindow().setBackgroundDrawable(new ColorDrawable(android.graphics.Color.TRANSPARENT));
dialog.getWindow().requestFeature(Window.FEATURE_NO_TITLE);
return dialog;
}
@Override
public void onResume() {
super.onResume();
// getDialog().getWindow().setLayout((7 * width) / 7, (4 * height) / 5);
}
public class BotConnectionDialogAdapter extends PagerAdapter {
/**
* View pager adapter
*/
private LayoutInflater layoutInflater;
public BotConnectionDialogAdapter() {
}
@Override
public Object instantiateItem(ViewGroup container, int position) {
layoutInflater = (LayoutInflater) getActivity().getSystemService(Context.LAYOUT_INFLATER_SERVICE);
View view = layoutInflater.inflate(layouts[position], container, false);
container.addView(view);
return view;
}
@Override
public int getCount() {
return layouts.length;
}
@Override
public boolean isViewFromObject(View view, Object obj) {
return view == obj;
}
@Override
public void destroyItem(ViewGroup container, int position, Object object) {
View view = (View) object;
container.removeView(view);
}
}
}
答案 0 :(得分：1)
/**
* To disable and enable scrolling on ViewPager, just set shouldScroll to true or false.
*/
public class ScrollableViewPager extends ViewPager {
private boolean shouldScroll = true;
public ScrollableViewPager(Context context, AttributeSet attrs) {
super(context, attrs);
}
public void setShouldScroll(boolean shouldScroll) {
this.shouldScroll = shouldScroll;
}
@Override
public boolean onTouchEvent(MotionEvent ev) {
return shouldScroll && super.onTouchEvent(ev);
}
@Override
public boolean onInterceptTouchEvent(MotionEvent ev) {
return shouldScroll && super.onInterceptTouchEvent(ev);
}
}
现在使用此 ScrollableViewPager 代替默认的 ViewPager 并在onPageSelected（）回调中使用 检查位置。如果它是最后一个位置，请在viewPager实例上调用 setShouldScroll（false）方法，这将使我们的ScrollableViewPager类中的 shouldScroll 为false，并最终使滚动无效为我们已覆盖 onTouchEvent（）和 onInterceptTouchEvent（）方法，该方法会检查 shouldScroll 的值。