Question

我的应用程序中有一个viewpager，它显示了一个字符串幻灯片。但是当我运行应用程序时，viewpager卡在第一个字符串上。然后才知道问题是什么？如何使字符串的幻灯片显示工作？

我的custompageradapter课程，我添加了我的主要活动

int [] mResources ={R.string.app_name, R.string.tip1, R.string.tip2};

class CustomPagerAdapter extends PagerAdapter {

    Context mContext;
    LayoutInflater mLayoutInflater;

    public CustomPagerAdapter(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);

        TextView pagertips = (TextView) itemView.findViewById(R.id.pagertext);
        pagertips.setText(mResources[position]);

        container.addView(itemView);

        return itemView;
    }

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

我将此添加到我的oncrease（）

CustomPagerAdapter mCustomPagerAdapter = new CustomPagerAdapter(this);

    ViewPager mViewPager = (ViewPager) findViewById(R.id.tipspager);
    mViewPager.setAdapter(mCustomPagerAdapter);

这是我的布局pager_item.xml

<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:orientation="vertical" android:layout_width="match_parent"
android:layout_height="match_parent">

<TextView
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:id="@+id/pagertext" />
</LinearLayout>

我添加了一个viewpager，这是我的主要布局文件 的 main.xml中

<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:paddingLeft="@dimen/activity_horizontal_margin"
android:paddingRight="@dimen/activity_horizontal_margin"
android:paddingTop="@dimen/activity_vertical_margin"
android:paddingBottom="@dimen/activity_vertical_margin"
android:id="@+id/relativeLayout">


<android.support.v4.view.ViewPager xmlns:android="http://schemas.android.com/apk/res/android"
    android:id="@+id/tipspager"
    android:layout_width="match_parent"
    android:layout_height="match_parent">
</android.support.v4.view.ViewPager>

</RelativeLayout>

Answer 1

Viewpager本质上不是自动的。您必须为其添加自动代码。在onCreate中添加以下代码

    Timer swipeTimer;
    final Handler handler = new Handler();

    final Runnable Update = new Runnable() {
        int currentPage = 0;
        public void run() {
            if (currentPage == (mResources.length)) {
                currentPage = 0;
            }
            viewPager.setCurrentItem(currentPage++, true);
        }
    };

    swipeTimer = new Timer();
    swipeTimer.schedule(new TimerTask() {

        @Override
        public void run() {
            handler.post(Update);
        }
    }, 100, 1000);

Answer 2

尝试这种方式会有所帮助

public class MainActivity extends Activity {

    // Declare Variables
    ViewPager viewPager;
    PagerAdapter adapter;
    String[] rank;
    String[] country;
    String[] population;
    int[] flag;

    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        // Get the view from viewpager_main.xml
        setContentView(R.layout.viewpager_main);

        // Generate sample data
        rank = new String[] { "1", "2", "3", "4", "5", "6", "7", "8", "9", "10" };

        country = new String[] { "China", "India", "United States",
                "Indonesia", "Brazil", "Pakistan", "Nigeria", "Bangladesh",
                "Russia", "Japan" };

        population = new String[] { "1,354,040,000", "1,210,193,422",
                "315,761,000", "237,641,326", "193,946,886", "182,912,000",
                "170,901,000", "152,518,015", "143,369,806", "127,360,000" };

        flag = new int[] { R.drawable.china, R.drawable.india,
                R.drawable.unitedstates, R.drawable.indonesia,
                R.drawable.brazil, R.drawable.pakistan, R.drawable.nigeria,
                R.drawable.bangladesh, R.drawable.russia, R.drawable.japan };

        // Locate the ViewPager in viewpager_main.xml
        viewPager = (ViewPager) findViewById(R.id.pager);
        // Pass results to ViewPagerAdapter Class
        adapter = new ViewPagerAdapter(MainActivity.this, rank, country, population, flag);
        // Binds the Adapter to the ViewPager
        viewPager.setAdapter(adapter);

    }
}

viewpager_main.xml

<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="fill_parent"
    android:layout_height="fill_parent" >

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

</RelativeLayout>

ViewPagerAdapter.java

public class ViewPagerAdapter extends PagerAdapter {
    // Declare Variables
    Context context;
    String[] rank;
    String[] country;
    String[] population;
    int[] flag;
    LayoutInflater inflater;

    public ViewPagerAdapter(Context context, String[] rank, String[] country,
            String[] population, int[] flag) {
        this.context = context;
        this.rank = rank;
        this.country = country;
        this.population = population;
        this.flag = flag;
    }

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

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

    @Override
    public Object instantiateItem(ViewGroup container, int position) {

        // Declare Variables
        TextView txtrank;
        TextView txtcountry;
        TextView txtpopulation;
        ImageView imgflag;

        inflater = (LayoutInflater) context
                .getSystemService(Context.LAYOUT_INFLATER_SERVICE);
        View itemView = inflater.inflate(R.layout.viewpager_item, container,
                false);

        // Locate the TextViews in viewpager_item.xml
        txtrank = (TextView) itemView.findViewById(R.id.rank);
        txtcountry = (TextView) itemView.findViewById(R.id.country);
        txtpopulation = (TextView) itemView.findViewById(R.id.population);

        // Capture position and set to the TextViews
        txtrank.setText(rank[position]);
        txtcountry.setText(country[position]);
        txtpopulation.setText(population[position]);

        // Locate the ImageView in viewpager_item.xml
        imgflag = (ImageView) itemView.findViewById(R.id.flag);
        // Capture position and set to the ImageView
        imgflag.setImageResource(flag[position]);

        // Add viewpager_item.xml to ViewPager
        ((ViewPager) container).addView(itemView);

        return itemView;
    }

    @Override
    public void destroyItem(ViewGroup container, int position, Object object) {
        // Remove viewpager_item.xml from ViewPager
        ((ViewPager) container).removeView((RelativeLayout) object);

    }
}

viewpager_item.xml

<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="fill_parent"
    android:layout_height="fill_parent"
    android:gravity="center"
    android:padding="10dp" >

    <TextView
        android:id="@+id/ranklabel"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="@string/ranklabel" />

    <TextView
        android:id="@+id/rank"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_toRightOf="@+id/ranklabel" />

    <TextView
        android:id="@+id/countrylabel"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_below="@+id/ranklabel"
        android:text="@string/countrylabel" />

    <TextView
        android:id="@+id/country"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_below="@+id/rank"
        android:layout_toRightOf="@+id/countrylabel" />

    <TextView
        android:id="@+id/populationlabel"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_below="@+id/countrylabel"
        android:text="@string/populationlabel" />

    <TextView
        android:id="@+id/population"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_below="@+id/country"
        android:layout_toRightOf="@+id/populationlabel" />

    <ImageView
        android:id="@+id/flag"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_alignParentRight="true"
        android:background="#000000"
        android:padding="1dp" />

</RelativeLayout>

如果您想要自动连续更改视图，则必须在活动中使用处理程序

Handler handler = new Handler();

        Runnable Update = new Runnable() {
            public void run() {
                if (currentPage == No_of_pages - 1) {
                    currentPage = 0;
                }
                featureViewPager.setCurrentItem(currentPage++, true);
            }
        };

        swipeTimer = new Timer();
        swipeTimer.schedule(new TimerTask() {

            @Override
            public void run() {
                handler.post(Update);
            }
        }, 100, 500);

查看寻呼机幻灯片无效

2 个答案: