使用viewpager滑动图像(而不是布局)

Question

我的代码做了什么:

这是我的代码,用于在xml布局之间滑动的viewpager(名为left.xml,right.xml和center.xml).

我想要它做什么

我想在图像之间滑动(存储在drawable文件夹中).当我用R.drawable.image替换R.layout.xml时,我的应用程序崩溃了.任何人都可以帮我搞清楚吗？

public class MainActivity extends Activity {

@Override
public void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main);

    MyPagerAdapter adapter = new MyPagerAdapter();
    ViewPager myPager = (ViewPager) findViewById(R.id.myfivepanelpager);
    myPager.setAdapter(adapter);
    myPager.setCurrentItem(0);
}

@Override
public boolean onCreateOptionsMenu(Menu menu) {
    getMenuInflater().inflate(R.menu.activity_main, menu);
    return true;
}

class MyPagerAdapter extends PagerAdapter {

    public int getCount() {
        return 3;
    }

    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.left;
            break;
        case 1:
            resId = R.layout.center;
            break;
        case 2:
            resId = R.layout.right;
            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 boolean isViewFromObject(View arg0, Object arg1) {
        return arg0 == ((View) arg1);

    }

    @Override
    public Parcelable saveState() {
        return null;
    }
}

}

Answer 1

如果您使用相同的实现,只是添加R.drawable.XXX而不是R.layout.YYY那时问题就在那里.您正在使用LayoutInflater膨胀ImageViews,布局不足,因为它本身表明它会在整体布局中膨胀View.

而不是那样尝试ImageView通过代码创建对象然后在return新创建的返回ImageView.一些示例代码将是:

public Object instantiateItem(View collection, int position) {

    ImageView img = new ImageView(context); //this is a variable that stores the context of the activity
    //set properties for the image like width, height, gravity etc...

    int resId = 0;
    switch (position) {
        case 0:
            resId = R.drawable.img1;
            break;
        case 1:
            resId = R.drawable.img2;
            break;
        case 2:
            resId = R.drawable.img3;
            break;
    }

    img.setImageResource(resId); //setting the source of the image
    return img;
}

如果您只是使用特定数量的图像或页面,则应考虑将其添加到包含ViewPager而不是动态创建的xml中ViewPager.