我正在使用网格视图，它会从布局中展开custom_layout。网格视图正在从手机加载视频并以缩略图的形式填充它。一切都很好。滚动网格视图时出现问题。它的滚动速度很慢，而且手机的API＆gt; 20正在提供消息应用未响应
我已经关注此链接，但没有找到完美的解决方案： Gridview is scrolling slow
我使用异步任务从图库中加载视频。我正在给出相同的代码。这是我的片段：
1。 AddFragment.java
public class AddFragment extends Fragment {
private ImageButton imageButton;
private GridView gridView;
private ProgressDialog videoProgressDialog;
ArrayList<File> list = new ArrayList<>();
ImageAdapter imageAdapter;
public AddFragment() {
// Required empty public constructor
}
@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
// Inflate the layout for this fragment
View view = inflater.inflate(R.layout.fragment_add, container, false);
imageButton = (ImageButton) view.findViewById(R.id.gotoButton);
gridView = (GridView) view.findViewById(R.id.grid_view);
gridView.setChoiceMode(ListView.CHOICE_MODE_MULTIPLE);
Log.e("ADD_VIDEOS","FRAGMENT CREATED");
videoProgressDialog = new ProgressDialog(getContext());
videoProgressDialog.setTitle("Loading Videos");
videoProgressDialog.setMessage("please wait.....");
videoProgressDialog.setCancelable(false);
videoProgressDialog.show();
LoadVideoTask videoTask = new LoadVideoTask();
videoTask.execute(new File("/mnt"));
return view;
}
//reading the file from the storage
void videoReader(File root) {
File[] file = root.listFiles();
if (file != null) {
for (File aFile : file) {
if (!aFile.isDirectory()) {
if (aFile.getName().endsWith(".mp4")) {
Log.e("VIDEO_FILE=====", aFile.getName());
list.add(aFile);
}
} else
videoReader(aFile);
}
} else{}
}
//Show hide select button if images are selected or deselected
public void showSelectButton() {
ArrayList<String> selectedItems = imageAdapter.getCheckedItems();
Log.e("CHECKED_ITEMS",imageAdapter.getCheckedItems().toString());
if (selectedItems.size() > 0) {
imageButton.setVisibility(View.VISIBLE);
} else
imageButton.setVisibility(View.GONE);
}
class ImageAdapter extends BaseAdapter {
private Bitmap bitmap;
private LayoutInflater inflater;
SparseBooleanArray mSparseBooleanArray;
private final Context context;
private ImageAdapter(Context c) {
context = c;
//changes done from here
mSparseBooleanArray = new SparseBooleanArray();
}
//Method to return selected Images
public ArrayList<String> getCheckedItems() {
ArrayList<String> mTempArry = new ArrayList<String>();
for (int i = 0; i < list.size(); i++) {
if (mSparseBooleanArray.get(i)) {
mTempArry.add(list.get(i).toString());
}
}
return mTempArry;
}
//for the video numbers
@Override
public int getCount() {
return list.size();
}
//for getting the video items position vise
@Override
public Object getItem(int position) {
return list.get(position);
}
@Override
public long getItemId(int i) {
return i;
}
@Override
public View getView(int position, View convertView, ViewGroup viewGroup) {
View v;
if (convertView == null) {
inflater = (LayoutInflater) context.getSystemService(Context.LAYOUT_INFLATER_SERVICE);
v = inflater.inflate(R.layout.custom_gridview,viewGroup,false);
v.setLayoutParams(new AbsListView.LayoutParams(215,215));
} else {
// picturesView = (ImageView) convertView;
v = (View)convertView;
}
Viewholder viewHolder = new Viewholder(v);
//viewHolder.imageView.setId(position);
viewHolder.id = position;
//convertView.setTag(viewHolder);
//loading images from the videos
if (list.get(position).toString().contains(".jpg")) {
bitmap = BitmapFactory.decodeFile(list.get(position).toString()); //Creation of Thumbnail of image
// viewHolder.imageView.setImageBitmap(bitmap);
} else {
if (list.get(position).toString().contains(".mp4")) {
bitmap = ThumbnailUtils.createVideoThumbnail(list.get(position).toString(), 1); //Creation of Thumbnail of video
viewHolder.imageView.setImageBitmap(bitmap);
}
}
//picturesView.setScaleType(ImageView.ScaleType.CENTER_CROP);
//picturesView.setAdjustViewBounds(true);
//picturesView.setLayoutParams(new GridView.LayoutParams(215, 215));
//picturesView.setImageBitmap(bitmap);
//setting layout params for every device
viewHolder.checkBox.setTag(position);
viewHolder.checkBox.setChecked(mSparseBooleanArray.get(position));
CompoundButton.OnCheckedChangeListener mCheckedChangeListener = new CompoundButton.OnCheckedChangeListener() {
@Override
public void onCheckedChanged(CompoundButton compoundButton, boolean isChecked) {
mSparseBooleanArray.put((Integer) compoundButton.getTag(), isChecked);//Insert selected checkbox value inside boolean array
showSelectButton();
}
};
viewHolder.checkBox.setOnCheckedChangeListener(mCheckedChangeListener);
//return picturesView;
return v;
}
class Viewholder {
public ImageView imageView;
public CheckBox checkBox;
public int id;
public Viewholder(View v){
imageView = (ImageView) v.findViewById(R.id.galleryImageView);
checkBox = (CheckBox) v.findViewById(R.id.selectCheckBox);
}
}
}
//asynch task has been done to do the processing in the background for loading the videos
//three parametres are Params,Progress,Result
private class LoadVideoTask extends AsyncTask<File,Integer, Integer>{
@Override
protected Integer doInBackground(File... files) {
for(int i=0;i<files.length;i++) {
videoReader(files[i]);
Log.e("VIDEO_LOAD", files[i].toString());
}
return files.length;
}
@Override
protected void onProgressUpdate(Integer... values) {
super.onProgressUpdate(values);
videoProgressDialog.setProgress(values[0]);
}
@Override
protected void onPostExecute(Integer integer) {
super.onPostExecute(integer);
updateUI();
}
}
private void updateUI() {
videoProgressDialog.dismiss();
//calling imageadapter class in here
imageAdapter = new ImageAdapter(getContext());
//for not repeating of the files
LinkedHashSet<File> fileList = new LinkedHashSet<>();
fileList.addAll(list);
list.clear();
list.addAll(fileList);
gridView.setAdapter(imageAdapter);
imageButton.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View view) {
Intent intent = new Intent(getContext(), EditVideoActivity.class);
intent.putExtra("sendData", imageAdapter.getCheckedItems()); //passing the data
Log.e("SEND_DATA", imageAdapter.getCheckedItems().toString());
startActivity(intent);
}
});
}}
由于存在大量数据，而且我知道由于数据量很大，因此滚动速度不慢。我需要一个解决方案。谢谢你提前。
EDITS
在关注此链接后，我得到了一个结果，并根据解决方案对getView（）进行了一些更改，但仍无法解决我的问题。
链接：GridView Smooth Scrolling Solution
我的getView（）现在是这样的：
我的Adapter类中的getView（）方法
@Override
public View getView(int position, View convertView, ViewGroup viewGroup) {
Viewholder viewHolder = null;
if (convertView == null) {
viewHolder = new Viewholder();
inflater = (LayoutInflater) context.getSystemService(Context.LAYOUT_INFLATER_SERVICE);
convertView = inflater.inflate(R.layout.custom_gridview,viewGroup,false);
convertView.setLayoutParams(new AbsListView.LayoutParams(215,215));
convertView.setTag(viewHolder);
} else {
viewHolder = (Viewholder) convertView.getTag();
}
viewHolder.imageView = (ImageView) convertView.findViewById(R.id.galleryImageView);
viewHolder.checkBox = (CheckBox) convertView.findViewById(R.id.selectCheckBox);
viewHolder.id = position;
//loading images from the videos
if (list.get(position).toString().contains(".jpg")) {
bitmap = BitmapFactory.decodeFile(list.get(position).toString()); //Creation of Thumbnail of image
// viewHolder.imageView.setImageBitmap(bitmap);
} else {
if (list.get(position).toString().contains(".mp4")) {
bitmap = ThumbnailUtils.createVideoThumbnail(list.get(position).toString(), 1); //Creation of Thumbnail of video
viewHolder.imageView.setImageBitmap(bitmap);
}
}
viewHolder.checkBox.setTag(position);
viewHolder.checkBox.setChecked(mSparseBooleanArray.get(position));
CompoundButton.OnCheckedChangeListener mCheckedChangeListener = new CompoundButton.OnCheckedChangeListener() {
@Override
public void onCheckedChanged(CompoundButton compoundButton, boolean isChecked) {
mSparseBooleanArray.put((Integer) compoundButton.getTag(), isChecked);//Insert selected checkbox value inside boolean array
showSelectButton();
}
};
viewHolder.checkBox.setOnCheckedChangeListener(mCheckedChangeListener);
return convertView;
}
答案 0 :(得分：0)
位图很容易耗尽应用程序的内存预算。
如果您的应用正在将多个位图加载到内存中，则需要熟练地管理内存和磁盘缓存。 因此，无论何时从视频加载图像，都必须耗尽应用程序的内存预算。
我建议使用Picasso库。（http://square.github.io/picasso/）
Picasso.with(context).load(new File(YOUR_FILE_PATH)).into(imageView);
您必须在源代码中更改它。
if (list.get(position).toString().contains(".mp4")) {
bitmap = ThumbnailUtils.createVideoThumbnail(list.get(position).toString(), 1); //Creation of Thumbnail of video
Picasso.with(context).load(getImageUri(context, bitmap)).into(viewHolder.imageView);}
public Uri getImageUri(Context inContext, Bitmap inImage) {
ByteArrayOutputStream bytes = new ByteArrayOutputStream();
inImage.compress(Bitmap.CompressFormat.JPEG, 100, bytes);
String path = MediaStore.Images.Media.insertImage(inContext.getContentResolver(), inImage, "Title", null);
return Uri.parse(path);
}
另请阅读
solving-the-android-image-loading-problem-volley-vs-picasso/