android - 如何在 Android 上开发图像轮播？

Question

我正在尝试在 Android 屏幕的上半部分放置一个旋转木马。

我喜欢 Bootstrap 轮播，例如:

http://www.w3schools.com/bootstrap/bootstrap_carousel.asp

我不确定处理此问题的最佳方法？我是否在屏幕的上半部分使用 GridView？？

Answer 1

首先，您必须在您的 xml 中创建一个 Viewpager，例如:

<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/pager"
        android:layout_width="match_parent"
        android:layout_height="match_parent">
    </android.support.v4.view.ViewPager>

</RelativeLayout>

对于自定义 Adapter，您需要创建一个 res/layout/pager_item.xml，它将用于膨胀并生成 Adapter 的 View :

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

    <ImageView
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        android:id="@+id/imageView" />

</LinearLayout>

之后，您可以创建自定义 Adapter 来设置您的 ViewPager:

public class CustomPagerAdapter extends PagerAdapter {

    private Context mContext;
    private LayoutInflater mLayoutInflater;
    private int[] mResources;

    public CustomPagerAdapter(Context context, int[] resources) {
        mContext = context;
        mResources = resources;
        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);
    }

}

然后将以下代码放入Activity中的onCreate:

mViewPager = (ViewPager) findViewById(R.id.pager);

// This is just an example. You can use whatever collection of images.
int[] mResources = {
    R.drawable.first,
    R.drawable.second,
    R.drawable.third,
    R.drawable.fourth,
    R.drawable.fifth,
    R.drawable.sixth
};

CustomPagerAdapter mCustomPagerAdapter = new CustomPagerAdapter(this, mResources);

mViewPager.setAdapter(mCustomPagerAdapter);

查看以下教程了解更多详情:http://codetheory.in/android-image-slideshow-using-viewpager-pageradapter/