【发布时间】：2017-08-03 07:11:24
【问题描述】：
我正在使用 ViewPager 插件 API 处理图片库。我正在从 sdcard 中的特定文件夹加载图像。我的目标是在 ViewPager 中每个屏幕只显示 9 张图像，这是我无法实现的。下面的代码是mainactivity。
public class AndroidSwipeGalleryActivity extends Activity {
private int size;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
super.setContentView(R.layout.image_gallery);
File file = new File(Environment.getExternalStorageDirectory()+"/xxxxxxx/images");
if (file.exists()) {
size = file.listFiles().length;
System.out.println("=====File exists====Length is====="+size);
double quo = (double)size/9;
System.out.println("====Dividing by 9====" + quo);
size = (int) Math.ceil(quo);
System.out.println("===Math===== "+size);
} else {
System.out.println("======File does not exists====");
}
MyPagerAdapter adapter = new MyPagerAdapter(this);
adapter.setScrCount(size);
ViewPager myPager = (ViewPager) findViewById(R.id.viewpager);
myPager.setAdapter(adapter);
myPager.setCurrentItem(0);
}
}
Pager Adapter 和 Image Adapter 在下面的类中：
public class MyPagerAdapter extends PagerAdapter {
private TextView tv;
private GridView gv;
private int scrCount;
private int count;
public int imageCount;
private Cursor cursor;
private int columnIndex;
private Activity act;
public MyPagerAdapter(Activity act) {
this.act = act;
}
public int getCount() {
return getScrCount();
}
public Object instantiateItem(View collection, int position) {
// /////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////
// Create the cursor pointing to the SDCard
String uri = MediaStore.Images.Media.DATA;
String condition = uri + " like '%/beverlyhills/images%'";
cursor = act.getContentResolver().query(MediaStore.Images.Media.EXTERNAL_CONTENT_URI, null, condition, null, null);
count = cursor.getCount();
System.out.println("Cursor count::::"+count);
// Get the column index of the Thumbnails Image ID
columnIndex = cursor.getColumnIndexOrThrow(MediaStore.Images.Thumbnails._ID);
// ////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////
LayoutInflater inflater = (LayoutInflater) collection.getContext().getSystemService(Context.LAYOUT_INFLATER_SERVICE);
int resId = 0;
for (int i = 0; i < getScrCount() ; i++) {
if (count > 9) {
if (position == i) {
int num = 0;
num = count - 9;
count = num;
imageCount = 9;
}
} else {
imageCount = count;
}
}
resId = R.layout.number_one;
View view = inflater.inflate(resId, null);
((ViewPager) collection).addView(view, 0);
tv = (TextView) collection.findViewById(R.id.swipeTitleTextView);
tv.setText("Swipe Gallery");
gv = (GridView) collection.findViewById(R.id.galleryGridView);
ImageAdapter imageAdapter = new ImageAdapter(collection.getContext(), imageCount);
gv.setAdapter(imageAdapter);
// Set up a click listener
gv.setOnItemClickListener(new OnItemClickListener() {
public void onItemClick(@SuppressWarnings("rawtypes") AdapterView parent, View v, int position, long id) {
// Get the data location of the image
String[] projection = {MediaStore.Images.Media.DATA};
cursor = act.managedQuery( MediaStore.Images.Media.EXTERNAL_CONTENT_URI,
projection, // Which columns to return
null, // Return all rows
null,
null);
columnIndex = cursor.getColumnIndexOrThrow(MediaStore.Images.Media.DATA);
cursor.moveToPosition(position);
// Get image filename
String imagePath = cursor.getString(columnIndex);
// Use this path to do further processing, i.e. full screen display
System.out.println("=====Image Path:::::"+imagePath);
}
});
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;
}
@Override
public void finishUpdate(View arg0) {
// TODO Auto-generated method stub
}
@Override
public void restoreState(Parcelable arg0, ClassLoader arg1) {
// TODO Auto-generated method stub
}
@Override
public void startUpdate(View arg0) {
// TODO Auto-generated method stub
}
public int getScrCount() {
return scrCount;
}
public void setScrCount(int scrCount) {
this.scrCount = scrCount;
}
private class ImageAdapter extends BaseAdapter {
private int count;
public ImageAdapter(Context ctx, int count) {
this.count = count;
}
@Override
public int getCount() {
return count;
}
@Override
public Object getItem(int position) {
return position;
}
@Override
public long getItemId(int position) {
return position;
}
@Override
public View getView(int position, View convertView, ViewGroup parent) {
ImageView picturesView;
if (convertView == null) {
picturesView = new ImageView(act);
// Move cursor to current position
cursor.moveToPosition(position);
// Get the current value for the requested column
int imageID = cursor.getInt(columnIndex);
// Set the content of the image based on the provided URI
picturesView.setImageURI(Uri.withAppendedPath(
MediaStore.Images.Thumbnails.EXTERNAL_CONTENT_URI, "" + imageID));
picturesView.setScaleType(ImageView.ScaleType.FIT_CENTER);
picturesView.setPadding(8, 8, 8, 8);
picturesView.setLayoutParams(new GridView.LayoutParams(100, 100));
}
else {
picturesView = (ImageView)convertView;
}
return picturesView;
}
}
}
问题是我能够加载图像并将它们显示在屏幕上，但无法在每个屏幕上准确显示 9 个图像。请过一遍代码，并不复杂。
【问题讨论】：
标签： android image gridview android-viewpager