ViewPager 删除一个页面

Question

如何从查看寻呼机中永久删除一个页面。当用户按下该屏幕上的按钮时，我想删除一个页面。我为此苦苦挣扎。我阅读了 pageradapter 的文档并找到了 destroyitem 但它对我帮助不大。我能够在 viewpager 中添加图像，但删除仍然给我带来困难。请帮忙。

下面是 activity 的代码，其中获取图像，我想根据用户请求删除图像。

public class ImageDisplayActivity extends Activity {
private List<String> filePaths;

@Override
public void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_display1);


    // Get Image Paths for the PagerAdapter
    filePaths = getIntent().getExtras().getStringArrayList("filePaths");
    int currPosition = getIntent().getExtras().getInt("position");

    ViewPager viewPager = (ViewPager) findViewById(R.id.view_pager);
    viewPager.setCurrentItem(currPosition);

    ImagePagerAdapter adapter = new ImagePagerAdapter();
    viewPager.setAdapter(adapter);
}

private class ImagePagerAdapter extends PagerAdapter {
    @Override
    public int getCount() {
        return filePaths.size();
    }

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

    @Override
    public Object instantiateItem(ViewGroup container, int position) {
        Context context = ImageDisplayActivity.this;
        ImageView imageView = new ImageView(context);

        int padding = 16;
        imageView.setPadding(padding, padding, padding, padding);
        imageView.setScaleType(ImageView.ScaleType.CENTER_INSIDE);

        // Get Image
        BitmapFactory.Options bmOptions = new BitmapFactory.Options();
        bmOptions.inJustDecodeBounds = false;
        bmOptions.inSampleSize = 4;
        bmOptions.inPurgeable = true;
        Bitmap bitmap = BitmapFactory.decodeFile(filePaths.get(position), bmOptions);

        // Display Image
        imageView.setImageBitmap(bitmap);

        ((ViewPager) container).addView(imageView, 0);
        return imageView;
    }

    @Override
    public void destroyItem(ViewGroup container, int position, Object imageView) {
        ((ViewPager) container).removeView((ImageView) imageView);
    }
}

}

Answer 1

正如@Kuffs 所说，从文件路径中删除项目，然后通知适配器底层数据已更改：

filePaths.remove(...); // Remove whatever you want
adapter.notifyDatasetChanged(); // Tell the adapter that it's time to update views

Answer 2

我正在发布一个答案，因为我无法发表评论。

您可以尝试将其从适配器中移除。将此添加到您的 destroyItem:

if(position == conditionToRemove){
    filePaths.remove(position); 
    adapter.notifyDatasetChanged()
}

并且，您必须将 ImagePagerAdapter 设为全局变量。希望这对您有所帮助！

ViewPager 删除一个页面

ViewPager delete a page

android

android-viewpager