Question

好的，所以我正在开发一个利用ViewPager来显示页面的Android应用程序。

在每个页面中，我有一组用于在页面之间导航的按钮（除了在页面之间滑动）。这些按钮用于“第一页”，“上一页”，“下一页”和“最后一页”。

我无法弄清楚该怎么做是设计一种机制，以便在按钮点击时启用页面更改。

有人有什么想法吗？

ETA：为了更好地解释设置，按钮在每个页面的布局中声明，并在PagerAdapter中用其余布局充气。我的问题是我无法在PagerAdapter中引用ViewPager。或者至少，我想不出办法。

Answer 1

按钮：

Button yourButton = (Button)findViewById(R.id.button1);
    yourButton.setOnClickListener(new OnClickListener() {

     @Override
           public void onClick(View view) {
               mViewPager.setCurrentItem(getItem(+1), true); //getItem(-1) for previous
           }
        });

功能：

private int getItem(int i) {
       return mViewPager.getCurrentItem() + i;
}

希望这会有所帮助：）

Answer 2

yourButton.setOnClickListener(new OnClickListener() {
   @Override
   public void onClick(View view) {
      yourViewPager.setCurrentItem(page, smoothScroll);
   }
});

Answer 3

我用这段代码完成了这个项目。

vPager = (ViewPager) findViewById(R.id.viewpager);
    View tempView1 = inflater.inflate(R.layout.ani_dialog1, null);
    firstView = (ImageView) tempView1.findViewById(R.id.ani_dialog_next);
    views.add(tempView1);
    firstView.setOnClickListener(new OnClickListener() {

        @Override
        public void onClick(View v) {
            // TODO Auto-generated method stub
            vPager.setCurrentItem(1, true);

        }
    });

Answer 4

1）制作布局

      <RelativeLayout
                android:layout_width="match_parent"
                android:layout_height="200dp"
                android:background="@color/white"
                android:weightSum="1">



                <android.support.v4.view.ViewPager
                    android:id="@+id/images_pager"
                    android:layout_width="match_parent"
                    android:layout_height="match_parent"
                    >
                </android.support.v4.view.ViewPager>

                <ImageView
                    android:id="@+id/img_next"
                    android:layout_width="35dp"
                    android:layout_height="35dp"
                    android:src="@drawable/forward_white"
                    android:background="@color/colorPrimary"
                    android:layout_centerVertical="true"
                    android:layout_alignParentRight="true"
                    android:layout_marginRight="5dp"
                    android:paddingTop="5dp"
                    android:paddingBottom="5dp"
                    />


                <ImageView
                    android:id="@+id/img_previous"
                    android:layout_width="35dp"
                    android:layout_height="35dp"
                    android:src="@drawable/back_white"
                    android:background="@color/colorPrimary"
                    android:layout_centerVertical="true"
                    android:layout_marginLeft="5dp"
                    android:layout_alignParentLeft="true"
                    android:paddingTop="5dp"
                    android:paddingBottom="5dp"/>


            </RelativeLayout>

2）设置自定义适配器

        CustomViewPagerAdapter  custompageradpter;
        ViewPager   mViewPager;
        mViewPager = (ViewPager)shareImagesDialouge.findViewById(R.id.images_pager); 
         custompageradpter = new CustomViewPagerAdapter(this);
         mViewPager.setAdapter(custompageradpter);

    public class CustomViewPagerAdapter  extends PagerAdapter {


        Context mContext;
        LayoutInflater mLayoutInflater;

        int[] mResources = {
                R.drawable.emoji_1,
                R.drawable.emoji_2,
                R.drawable.emoji_3,
                R.drawable.emoji_4,
                R.drawable.emoji_5,
                R.drawable.emoji_6
        };

        public CustomViewPagerAdapter(Context context) {
            mContext = context;
            mLayoutInflater = (LayoutInflater) mContext.getSystemService(Context.LAYOUT_INFLATER_SERVICE);
        }

        @Override
        public int getCount() {
            return mResources.length;
        }

        @Override
        public boolean isViewFromObject(View view, Object object) {
            return view == ((LinearLayout) object);
        }

        @Override
        public Object instantiateItem(ViewGroup container, int position) {
            View itemView = mLayoutInflater.inflate(R.layout.pager_item, container, false);

            ImageView imageView = (ImageView) itemView.findViewById(R.id.imageView);
            imageView.setImageResource(mResources[position]);

            container.addView(itemView);

            return itemView;
        }

        @Override
        public void destroyItem(ViewGroup container, int position, Object object) {
            container.removeView((LinearLayout) object);
        }

    }

3）对于下一个和上一个按钮

         case R.id.img_previous:
                    mViewPager.setCurrentItem(getItemofviewpager(-1), true);
                    break;

                case R.id.img_next:
                    mViewPager.setCurrentItem(getItemofviewpager(+1), true);
                    break;

4）制作此功能

  private int getItemofviewpager(int i) {
        return mViewPager.getCurrentItem() + i;
    }

Answer 5

防病毒升级到sweggersen's和Alex Orlov's，

// For scrolling to next item
nextPageButton.setOnClickListener(new OnClickListener() {

    @Override
    public void onClick(View view) {
        viewPager.setCurrentItem(getNextPossibleItemIndex(1), true);
    }
});

// For scrolling to previous item
previousPageButton.setOnClickListener(new OnClickListener() {

    @Override
    public void onClick(View view) {
        viewPager.setCurrentItem(getNextPossibleItemIndex(-1), true);
    }
});

在Activity / Fragment中添加getNextPossibleItemIndex（）方法，

private int getNextPossibleItemIndex (int change) {

    int currentIndex = viewPager.getCurrentItem();
    int total = viewPager.getAdapter().getCount();

    if (currIndex + change < 0) {
        return 0;
    }

    return Math.abs((currentIndex + change) % total) ;
}

这样，您就可以更改currentItem而无需担心IndexOutOfBoundsException as suggested by Heinrich's comment。请注意，使用此方法，项目将显示为圆形列表。

1 -> 2 -> 3 -> 1 -> 2 -> 3 -> 1

但回过头来，它会停在第一项

1 <- 1 <- 2 <- 3

Answer 6

更新代码

Button preButton = (Button)findViewById(R.id.pre_button);
        Button nextButton = (Button)findViewById(R.id.next_button);

        preButton.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {

                mViewPager.setCurrentItem(mViewPager.getCurrentItem()-1, true); 


            }
        });

        nextButton.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {

                mViewPager.setCurrentItem(mViewPager.getCurrentItem()+1, true); 

            }
        });

Answer 7

这样做：

from pynput.keyboard import Key, Controller
def game():
    keyboard = Controller()
    if key.press():
        s = Sound()
        s.read("Cymatics - Guitar Chord Loop 2 - 128 BPM Dmaj")
        s.play()

print "Welcome to soundboard"
print "You will see a list of sound names, just write the name of it"
print "If you want to stop it type stop"
print "Type start"

start = input()
if start.lower() == "start":
    while True:
        game()
else:
    print "Ups, try again.."

要防止IndexOutOfBoundsException，您应该隐藏并显示两个按钮，如下所示：

backButton=(Button)findViewById(R.id.back_button);
nextButton=(Button)findViewById(R.id.next_button);
backButton.setVisibility(View.INVISIBLE);//you can use GONE or even disable it. It depends on your layout 


    nextButton.setOnClickListener(new OnClickListener() {

        @Override
        public void onClick(View view) {
            viewPager.setCurrentItem(viewPager.getCurrentItem()+1, true);
        }
    });


    backButton.setOnClickListener(new OnClickListener() {

        @Override
        public void onClick(View view) {
            viewPager.setCurrentItem(viewPager.getCurrentItem()-1, true);
        }
    });
}

Answer 8

首先创建一个界面

public interface OnPageChangedListener {
void OnPageChanged(int position);      }

下一步，使用OnPageChangedListener接口实现您的活动并执行以下操作

private void setupViewPager(ViewPager viewPager){
    viewPagerAdapter = new ViewPagerAdapter(getSupportFragmentManager());
    viewPagerAdapter.addFragment(new Fragment1(this));
    viewPagerAdapter.addFragment(new Fragment2(this));
    viewPagerAdapter.addFragment(new Fragment3(this));
    viewPagerAdapter.addFragment(new Fragment4(this));
    viewPagerAdapter.addFragment(new Fragment5(this));
    viewPagerAdapter.addFragment(new Fragment6(this));
    viewPager.setAdapter(viewPagerAdapter);
}
@Override
public void OnPageChanged(int position) {
    viewPager.setCurrentItem(position);
}

在片段中，使用创建一个

private OnPageChangedListener listener;

public Fragment1(OnPageChangedListener listener1) {
    this.listener = listener1;
}

ViewPagerAdapter

public class ViewPagerAdapter extends FragmentPagerAdapter {
private final List<Fragment> mFragmentList = new ArrayList<>();

public ViewPagerAdapter(FragmentManager manager) {
    super(manager);
}

@Override
public Fragment getItem(int position) {
    switch (position) {
    }
    return mFragmentList.get(position);
}

@Override
public int getCount() {
    return mFragmentList.size();
}

public void addFragment(Fragment fragment) {
    mFragmentList.add(fragment);
}}

希望这对您有帮助

Answer 9

public void onClick(View v) {
     int currentItem = mViewPager.getCurrentItem();
     mViewPager.setCurrentItem(currentItem+1); //(currentItem-1)
}

按钮单击中只有此代码： @Override

getcurrentitem是viewpager中的实际项目，下一项是currentItem + 1

Android ViewPager上一个/下一个按钮

9 个答案: